1.
The diagram shows the structure of a synapse. Presynaptic im p u ls e
M ito c h o n d rio n Presynaptic m e m b ra n e
S y n a p tic v e s ic le s
Postsynaptic m e m b ra n e
Postsynaptic im p u l se
(a)
Describe Describe what what would would happen happen in the the presynapt presynaptic ic neurone neurone as a result result of the the arrival arrival of an action potential. .......................................................................... ................................................................................................................ .......................................................... .................... .......................................................................... ................................................................................................................ .......................................................... .................... .......................................................................... ................................................................................................................ .......................................................... .................... .......................................................................... ................................................................................................................ .......................................................... .................... .......................................................................... ................................................................................................................ .......................................................... .................... .......................................................................... ................................................................................................................ .......................................................... .................... (3)
1
(b)
The graphs graphs below show the changes changes in membrane membrane potential potential in the presyna presynaptic ptic neurone neurone and the postsynaptic neurone as an impulse passes across a synapse. +40 Presynaptic neurone
+20 M e m b ra n e p o t e n t ia l /m V
0 1
2
3
4
5
6
T im e /m s
–20 –40 –60 –80 +40 Postsynaptic neurone
+20 M e m b ra n e p o t e n t ia l /m V
0 1
2
3
4
5
6
T im e /m s
–20 –40 –60 –80
(i)
On the the graph graph for for the the postsy postsynapti napticc neurone, neurone, indicate indicate by by using using a letter letter S the point at which the sodium channels open, allowing an increased flow of sodium ions into the neurone. (1)
(ii)
On the the graph graph for for the postsynaptic neurone, indicate by by using using a letter P the point at at which the potassium channels open, allowing an increased flow of potassium ions out of the neurone. (1)
(iii)
Calculate the delay between the arrival of the action potential at the presynaptic presynaptic neurone and the production of an action potential in the postsynaptic neurone. Show your working.
Answer .............................................................. .............................................................. (2)
(iv)
Explain Explain the reason for this delay. ......................................................................... ............................................................................................................... ................................................. ........... ......................................................................... ............................................................................................................... ................................................. ........... ......................................................................... ............................................................................................................... ................................................. ........... ......................................................................... ............................................................................................................... ................................................. ........... (2) (Total 9 marks)
3
2.
In mammals, control of the rate of ventilation ensures that body cells have an adequate supply of oxygen. The diagram summarises the i nfluence of carbon dioxide concentration in the blood upon ventilation rate.
Increase detected
I n c re a s e in C O in t h e b lo o d
I n c r e a s e in v e n ti la t io n r a t e
D e c re a s e in C O in t h e b l o o d
2
O p tim u m c o n c e n tra tio n o f C O in t h e b l o o d
D e c re a s e in C O in t h e b l o o d
2
D e c re a s e detected
(a)
2
2
I n c re a s e in C O in t h e b l o o d
2
D e c r ea s e in v e n ti la t io n r a t e
Give the the term term used used to descri describe be a control control mechanis mechanism m such such as the one one shown shown in the diagram. .......................................................................... ................................................................................................................ .......................................................... .................... (1)
(b) (b)
(i) Nam Name the the type type of recep ecepto torr whic which h dete detect ctss an incr increa easse or decre ecreas asee in the the concentration of carbon dioxide in the blood. ......................................................................... ............................................................................................................... ................................................. ........... (1)
(ii)
Name two places in the body where these receptors are located. 1 ...................................... ............................................................................ ............................................................................ ........................................... ..... 2 ...................................... ............................................................................ ............................................................................ ........................................... ..... (2)
(c) (c)
Iden Identi tify fy one physiological factor, other than a change in blood CO 2 concentration, which would cause an increase in the rate of ventilation. .......................................................................... ................................................................................................................ .......................................................... .................... (1)
(d)
Give one physiological effect, other than an increase in ventilation rate, that is caused by an increase in the concentration of carbon dioxide in the blood. .......................................................................... ................................................................................................................ .......................................................... .................... .......................................................................... ................................................................................................................ .......................................................... .................... (1) (Total 6 marks)
3.
The diagram below shows a section through a human brain.
A
C B
5
Complete the table below by writing in the letter and the name of the region of the brain that carries out each function. Function
Letter
Name of region
Initiating and controlling voluntary muscle movement Coordinating skeletal muscle movement, balance and posture Controlling heart and breathing rate (Total 4 marks)
4.
The diagram shows a longitudinal section through part of the axon of a myelinated neurone.
M y e lin sheath
(a)
Describe Describe the structure structure of the myelin sheath. sheath. ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… (2)
(b)
The table table shows shows the speed speed of conduct conduction ion of of an impuls impulsee along along axons axons with with differen differentt diameters. Data from both myelinated and non-myelinated neurones are included. Diameter of axon /µ m
Speed of conduction /m s –1
Non-myelinated
2
2
Non-myelinated
15
5
Non-myelinated
700
22
Myelinated
10
30
Myelinated
15
80
Type of neurone
With reference to the data, describe and explain the effect that the myelin sheath has on the speed of conduction of a nerve impulse. ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… (5) (Total 7 marks)
5.
Give an account of the role of pigments in the detection of light by flowering plants and animals.
(Allow three lined pages) (Total 10 marks)
7
6.
In an investigation into the effect of a drug on the nervous system, the reaction time of four volunteers was tested by timing how long it took for them to push a button after seeing a lamp light up. Volunteer A drank 50 cm 3 of water. Volunteers B, C and D each drank 50 em’ of a solution containing different concentrations of the drug. The reaction time of each volunteer was then tested every ten minutes during the next hour.
R e a c tio n tim e / s e c o n d s
Volunteer
C o n c e n t ra tio n of drug/ a r b i t r a r y u n i ts
0 m in
1 0 m in
2 0 m in
3 0 m in
4 0 m in
5 0 m in
6 0 m in
A
0
0 .3
0 .3
0 .2
0 .2
0 .2
0 .2
0 .2
B
1
0 .3
0 .4
0 .4
0 .4
0 .3
0 .2
0 .3
C
2
0 .2
0 .5
0 .6
0 .6
0 .5
0 .4
0 .4
D
3
0 .3
0 .8
0 .9
1 .0
1 .0
0 .9
0 .9
(a)
Suggest Suggest what what the data indicate indicate about about the absor absorption ption of the the drug drug into into the bloodstrea bloodstream. m. Give a reason for your answer. ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… (2)
(b)
Describe the effects effects that that the drug had upon the reaction reaction times of the volunteers volunteers during the 60 minutes of the investigation. ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… (3)
(c)
This drug is known to affect synaptic synaptic transmission. transmission. Suggest how the drug drug might might cause cause the the effects you have described in (b). ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… ……………………………………………….……………………………………… (3)
(d)
Give three factors, other than the concentration of the drug, that would need to be taken into account in this investigation. 1 …………………………………………….……………………………………… 2 …………………………………………….……………………………………… 3 …………………………………………….……………………………………… (3) (Total 11 marks)
7.
Multiple sclerosis is a disease of the nervous system in which the myelin sheath around the neurones of the central nervous system is damaged. The symptoms of multiple sclerosis are wide ranging, including loss of limb control, tiredness, speech impairment and eye problems. The exact cause of the disease is unknown, but it appears to involve the body’s immune system attacking the myelin. The myelin is made up of many cell membranes packed closely together, and so consists mostly of lipids and proteins. In multiple sclerosis, it is destroyed and replaced by scar tissue. Describe the role of the myelin sheath and suggest how damage to the myelin sheath could interfere with the transmission of nerve impulses.
(Allow one lined page) (Total 6 marks)
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8.
The diagram below shows the neurones involved in a spinal reflex arc.
Receptor S e n s o ry n e u r o n e
P o r tio n o f spinal cord
N euron e X
E f f e c to r ( m o t o r ) n e u r o n e S y n a p ti c c le f t E ff e c to r
(a) (a)
Name Name neur neuron onee X. .......................................................................... ................................................................................................................ ..................................................... ............... (1)
(b)
Explain Explain the the signifi significance cance of this neurone neurone in a reflex arc. .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... (2)
(c)
Describe Describe how how an action potential potential is produced produced in in the effector effector neuron neurone, e, followin following g the diffusion of transmitter substance across the synaptic cleft. .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... .......................................................................... ................................................................................................................ ..................................................... ............... (4) (Total 7 marks)
9.
The diagram below represents a section through the human retina.
C
o
n
R
o
d
B
i p
G
a
T
o
e c
o
n
l
g b
l r a
11
(a)
Name the retinal retinal pigment pigment found in a rod cell. .......................................................................... ................................................................................................................ .................................................................. ............................ (1)
(b)
Explain Explain how the the pigment pigment in rod cells cells is involved involved in the the conversion conversion of light light energy energy into into nerve impulses. .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ (4)
(c)
Using the information in the diagram, suggest why stimulation of cone cells results in a more detailed image than stimulation of rod cells. .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ (3)
(d)
The eye eye of a species species of of moth moth contains contains three different pigments. The table below shows the wavelengths and colours of light which are most strongly absorbed by these pigments. Pigm Pigmen entt
Wavel avelen eng gth most ost stron trongl gly y abso absorb rbed ed/n /nm m
A
350 (ultraviolet)
B
440 (violet)
C
525 (green)
Using information in the table, and your knowledge of the retinal pigments in the human eye, compare the sensitivity to colour of the moth's eye with that of the human eye. .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ .......................................................................... ................................................................................................................ .................................................................. ............................ (3) (Total 11 marks)
10.
Give an account of the sequence of events by which the arrival of an action potential at a synapse results in an action potential in the post-synaptic neurone.
(Allow two lined pages) (Total 8 marks)
13
11.
The diagram below shows a transverse section of the spinal cord of a mammal.
A B W m
h a
i t e t t e r
C
(a)
Name the parts labelled labelled A, B, and C. A .......................................................................... ................................................................................................................ ............................................................... ......................... B ...................................... .............................................................................. .............................................................................. ........................................................... ..................... C ...................................... .............................................................................. .............................................................................. ........................................................... ..................... (2)
(b)
The white white matter matter in the spinal spinal cord is mainly mainly compos composed ed of of the myelinated myelinated axons of neurones. The graph below shows the conduction velocity of myelinated and nonmyelinated neurones.
8 C
o
n
d
u
c
t i o
–
n
1
v
e
l o
c
i t y
/
m
s
M
y
e
l i n
a
t e
d
6
4
N
o
n
- m
y
e
l i
2
0 0
1
2 A
(i)
x d o i na
m /
3 me t e
4 r
Compare Compare the the conduct conduction ion velocit velocities ies of myelinated myelinated and non-myelin non-myelinated ated neurones. neurones. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… (3)
15
(ii)
Explain Explain the the role of myelin in nerve impulse impulse transmis transmission. sion. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… (2)
(c)
Explain Explain how simple simple reflexe reflexess are importa important nt in the the response responsess of mammals mammals to changes changes in the external environment. …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… (2) (Total 9 marks)
12.
The data below show some of the changes that occur in the cardiovascular system as a result of different levels of exercise. Level of exercise
Heart rate
At rest
Light
Medium
Intense
72
144
160
190
5
13
16
21
–1
/beats min
Cardiac output 3
–1
/dm min
(a)
Using the data data from from the the table, table, calculate calculate the stroke stroke volume volume when exercising exercising at an intense intense level. Show your working.
Answer ......................................... ......................................... (2)
(b)
The graph graph below shows shows typical typical blood blood pressu pressures res at at different different levels of exercise exercise..
2 B
l o
o
d
p
r e
0
0
s s u
r e
1
5
0
1
0
0
5
/
m
m
H
g
0
S p
y
s t r e s
D p
i a s r e s
0 A
(i)
t
r e s Lt L
i g h Mt e v e l
e o
d f
i Iu n m t e n s e e x e r c i s e
Explain Explain what what is meant meant by the term term blood pressure. ……………………………………………………………………………………… ……………………………………………………………………………………… (1)
17
(ii)
With reference to the graph, describe the effect of exercise on blood pressure. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… (3)
(iii)
Using the data in the table and the graph, suggest suggest why the systolic pressure rises with increasing level of exercise. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… (2)
(c)
State two sites in the body where blood pressure receptors are found. 1 ....................................................................... ............................................................................................................. .................................................................. ............................ 2 ....................................................................... ............................................................................................................. .................................................................. ............................ (2) (Total 10 marks)
13.
Parkinson’s disease leads to the gradual loss of balance and movement, often with muscle tremors. This disease is believed to be caused by a lack of the neurotransmitter dopamine in parts of the brain. The disease can be treated with the drug L-dopa. (a)
Explain Explain why the lack lack of of dopamine dopamine leads leads to to the symptoms symptoms of of Parkinson Parkinson’s ’s disease disease.. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(b)
Suggest Suggest why L-dopa, L-dopa, rather rather than than dopamine, dopamine, is is used for the the treatment treatment of of patients patients with with Parkinson’s disease. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (1)
(c)
Multiple Multiple sclerosis sclerosis is a disease disease that causes causes patches patches of inflammat inflammation ion in the the brain. brain. State State the name of an imaging technique and describe how the images could be used to establish which parts of the brain have been damaged in a patient with multiple sclerosis. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3) (Total 6 marks)
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14.
There is much debate about the reasons for variation in human characteristics. One source of evidence in this ‘nature and nurture’ debate is provided by studies of identical (monozygotic or MZ) twins. In one study, which involved 69 pairs of identical twins, fifty pairs of the twins had been brought up together since birth and nineteen pairs of the twins had been brought up apart since birth. The height, body mass and intelligence (IQ) of each twin was measured and the difference between each pair was determined for each characteristic. The table below shows the mean differences between the pairs of twins. Mean difference Char Charac acte teri rist stic ic
50 pair pairss of iden identi tica call twin twinss brought up together
19 pairs of identical twins brought up apart
Height/cm
1.7
1.8
Body mass/kg
1.9
4.5
Intelligence (IQ)
3.1
6.0
(a)
Explain Explain what these figures figures suggest suggest about about the effects effects of nature nature and and nurture nurture on these these three three characteristics. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
(b) (b)
Sug Suggest gest two reasons why the conclusions drawn from the data above should be treated with caution. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 5 marks)
15.
(a) Explain Explain how how nerve nerve impulses impulses are conduct conducted ed along along a myelinated myelinated axon axon after after an action action potential has been initiated. You should write your answer in continuous prose. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (6)
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(b)
Habituation Habituation is a type of of learning learning that allows animals animals to ignore ignore repeated repeated unimpo unimportant rtant stimuli. For example, snails withdraw their tentacles when the tentacles are gently touched, but if the tentacles are repeatedly stimulated in this way they are no longer withdrawn.
The diagram below shows a synapse involved in this type of response.
C a l c i u m C c h a n n e l
N
e
u
r o
n
e
1
2
a+
N
e
u
r
With repeated stimulation the calcium channels become less responsive. Using the diagram of the synapse and your own knowledge, suggest how changes in the functioning of the synapse might bring about habituation. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (4) (Total 10 marks)
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16.
The table below refers to some regions of the brain and their functions. Complete the table by inserting the correct word or words. Region of brain
One function
Medulla Learning and memory
Control of balance and fine movement
Hypothalamus (Total 4 marks)
17.
Neurones transmit electrical impulses along their cell surface membranes when stimulated to do so. These impulses are called action potentials and involve changes in the electrical potential across the membranes due to movement of positive ions. The diagram below shows the distribution of charge inside and outside an unmyelinated axon as an impulse passes along.
D + –
A
x
o
+
+
+
i r e c t i o +
+
+
n
+
o +
f
i m
p
+
+
+
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
+
+
+
n – +
+
+
+
D
+
+
+
C
+
+
B
A
(a)
Use the the most suitable suitable term from the the list list below to to describe describe the the state state of the the axon in regions regions B, C and D. Region A has been done for you. Depolarising
Resting
Repolarising
A
Resting
B
........... ................. ............ ............ ............ ............ ............ ............ ............ ............ ........... .....
C
........... ................. ............ ............ ............ ............ ............ ............ ............ ............ ........... .....
D
........... ................. ............ ............ ............ ............ ............ ............ ............ ............ ........... ..... (2)
(b)
The diagra diagram m below below shows shows two action potentials potentials recorded recorded using using an oscillosc oscilloscope. ope.
+
6
0
M e m b r a n e + 4 0 p o t e n t i a l / m V + 2 0 0
–
–
2
0
–
4
0
–
6
0
–
8
0
1
0 0
X
0 1
2
3
4 T
5
6
7
i m
e /
m
8
9
s
25
(i)
Explain Explain how how the the change change in membrane membrane potential potential between between 0.5 and 2.0 millisecond millisecondss is brought about. ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ ......................................................................... ............................................................................................................... ...................................................... ................ (4)
(ii)
Calculate Calculate the the number number of of action action potentia potentials ls occurrin occurring g per second. second. Show Show your your working.
Answer .................................. per second (2)
(c)
Explain Explain what what is taking place during the period period marked marked X on the diagram diagram in part part (b). .......................................................................... ................................................................................................................ ............................................................ ...................... .......................................................................... ................................................................................................................ ............................................................ ...................... .......................................................................... ................................................................................................................ ............................................................ ...................... .......................................................................... ................................................................................................................ ............................................................ ...................... .......................................................................... ................................................................................................................ ............................................................ ...................... .......................................................................... ................................................................................................................ ............................................................ ...................... (3) (Total 11 marks)
18.
Give an account of the detection of light by pigments in the mammalian eye.
(Allow two lined pages) (Total 9 marks)
(a) The table table below below compares compares three features features of nervous nervous and and hormona hormonall coordinati coordination. on. Complete the table to show the differences between the two types of coordination.
19.
Feature
Nervous coordination
Hormonal coordination
Method of transmission
Speed of transmission
Duration of the response (3)
(b)
Give one similarity between the methods of transmission involved in nervous and hormonal coordination. .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... (1) (Total 4 marks)
20.
Give an account of the location and functions of each of the following areas of the mammalian brain: cerebral hemispheres, cerebellum and medulla.
(Allow two lined pages) (Total 10 marks)
27
21.
The diagram below illustrates some aspects of the regulation of heart rate.
(a)
Complete Complete the the flow diagram diagram by naming naming the part of the the heart heart that receives receives impulse impulsess from from the two nerves (1)
(b)
Strenuous physical activity will will increase increase the volume of blood flowing through the venae cavae and into the right atrium. This will trigger a reflex action. (i)
Name Name the reflex reflex that that will be initiat initiated. ed. ......................................................................... ............................................................................................................... ...................................................... ................ (1)
(ii)
Using your own knowled knowledge ge and and the information information provided, provided, explai explain n how this increase in blood volume in the venae cavae and right atrium causes a change in heart rate. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. ......................................................................... ............................................................................................................... ....................................................... ................. (3)
(c)
The coordination coordination of the heart beat beat is disrupted when the conducting conducting systems systems of of the the heart are damaged. This type of disease is called heart block. Describe how an artificial pacemaker can be used to treat this condition. .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... .......................................................................... ................................................................................................................ ............................................................. ....................... (3) (Total 8 marks)
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22.
The diagram below shows a vertical section through a human brain.
A
E
D
B C
(a) (a)
Usin Using g the the lett letter erss A, B, C, D or E, state which region of the brain: (i) (i)
coor coordi dina nates tes move moveme ment nt ......................................................................... ............................................................................................................... .................................................. ............ (1)
(ii) (ii)
contro controls ls heart heart rate rate ......................................................................... ............................................................................................................... .................................................. ............ (1)
(iii)
receives receives sensory sensory input from the eyes. ......................................................................... ............................................................................................................... .................................................. ............ (1)
(b)
Researcher Researcherss covered covered one one eye of a new born kitten. kitten. Three Three months months later, later, when the the eye was uncovered, the kitten remained blind in that eye. Covering the eye of an adult cat for three months did not blind it. Explain what these results show about how vision develops in cats. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 5 marks)
23.
The graph below shows the effect of light intensity on the area of the pupil in the human eye.
5 4 P /
u m
p 2
i l m
a r e a 3 2 1 0 0
1 L
(a) (a)
(i)
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h
t
i n
3 t e
n
s i t y
/
Des Describ cribee the the effe effect ct of chan chang ging ing lig light inte intens nsit ity y on the the area area of the the pupi pupil. l.
......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (1)
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(ii)
Explain Explain how how the the muscles muscles in the the eye bring about this change. change. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (2)
(b)
Change Change in area area of the the pupil pupil is control controlled led by a reflex reflex action. action. In this this pupil pupil reflex, reflex, name name (i) (i)
the the rece recept ptor or ......................................................................... ............................................................................................................... .................................................. ............ the effector ......................................................................... ............................................................................................................... .................................................. ............ (1)
(ii)
Explain Explain why why the pupil reflex still occurs occurs in an uncons unconscious cious person. person. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (1)
(c)
Atropine Atropine is used to dilate dilate the the pupil pupil to allow allow the the eye to be examined examined more more easily. easily. Atropine inhibits the activity of acetylcholine. Suggest how atropine causes this inhibition. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(d)
The diagram diagram shows shows a light sensit sensitive ive cell cell from the eye. eye. The activity activity of the cell in the dark is shown. D
a
r k
R O u t e r s e g m e n
h
o
d
o
p
s i n
p
t S o d i u m (N a + ) i o n s
I n n s e g
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y
e r m e n
n
a p
t
s e N B
e i p
u
r o o
t r a n
l a r
c e
s m l l
Using the above diagram and your own knowledge, explain how light causes the depolarisation of the bipolar cell. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (5) (Total 12 marks)
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24.
(a) The graph graph below shows shows the changes changes in membra membrane ne potential potential of a myelinated myelinated nerve nerve fibre when a nerve impulse travels along it. The maximum depolarisation in the nerve fibre is +40 mV.
+
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(i)
On the the graph, graph, draw an arrow arrow to show show the the time when the sodium sodium ion channels channels open. (1)
(ii)
Explain Explain the meaning meaning of the term myelinated. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (2)
(iii)
State what what effect effect myelinat myelination ion has on the speed of conductio conduction. n. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (1)
35
(b)
On the graph below show the changes changes in membrane membrane potential potential of of a nerve nerve fibre, fibre, with a resting potential of –60mV and a maximum depolarisation of +35mV, during the passage of an impulse.
+
4
0
+
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V m / l a i t n e t o p
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6 T
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i m
e
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(2) (Total 6 marks)
25.
Nerve impulses travel across a synapse from a sensory neurone to a relay neurone in the spinal cord. Describe how a nerve impulse i mpulse is transmitted across a synapse. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. (Total 6 marks)
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26.
The diagram below shows one type of mammalian neurone.
D
e
C
e l l
N
n
o
S
y
d
b
d
n
r i
o
e
a
o
p
t
(a) (a)
(i)
Nam Name the the type type and and state tate the the role role of the the neu neurone rone sho shown in the the diag diagrram. am.
Type: ..................................... ........................................................................... ........................................................................... ..................................... Role: ....................................................................... ............................................................................................................. .......................................... .... ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (2)
39
(ii)
Draw an an arrow arrow on the diagram diagram to show show the direction direction in in which which an impulse impulse would would travel. (1)
(b)
State precisely precisely where in the the central nervous system the cell body of this type type of neurone is found and explain the importance of the dendrites. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
41
(c)
Describe Describe the the node node of of Ranvier Ranvier and explain explain its importance importance in the the neurone neurone.. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3) (Total 8 marks)
27.
The human brain has many different neurotransmitters which influence behaviour. One of these neurotransmitters is serotonin. A lack of serotonin in the brain can cause depression and an excess can cause anxiety. Drugs that increase levels of serotonin are used as antidepressants. The diagram below shows a synapse in which serotonin acts as a neurotransmitter.
p r e s y n a p p t o i cs t s y n a p t i c m e m b r a mn e e m b r a n e
s y n a p c l e f t
t i c
S e r o t o n i n s y n t h e s i s
V e s i c l e s e r o t o n K
(a)
c
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t a
i n
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i n
e y
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In sufferer suffererss of depres depression sion the the levels levels of serotonin serotonin are reduced. reduced. Using Using the diagram diagram above, above, suggest one explanation for low serotonin levels. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (1)
43
(b)
Use the the diagram diagram and and your your own own knowledg knowledgee of synapt synaptic ic transmis transmission sion to to explain explain how how information is transmitted across a synapse. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (6)
(c)
Using the information information given, given, suggest suggest and explain explain two ways antidepressants work. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(d)
The drug known as ecstasy (MDMA) can cause anxiety. The diagram below represents an ecstasy molecule. Using your knowledge and the diagrams provided suggest how ecstasy may have this effect.
.......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3) (Total 12 marks)
28.
The diagram below shows a vertical section through a human brain.
(a)
On the the diagram, diagram, draw draw an arrow to show show the position position of the hypothalamus. (1)
45
(b)
The forebra forebrain, in, midbrain midbrain and and hindbra hindbrain in are the the three three main regions regions of the human human brain. brain. State in which region of the brain the hypothalamus is found. .......................................................................... ................................................................................................................ ........................................................... ..................... (1)
(c)
Give two functions of the hypothalamus. 1 ....................................................................... ............................................................................................................. ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... 2 ....................................................................... ............................................................................................................. ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 4 marks)
29.
The diagram below shows a section through part of a mammalian retina.
(a)
A
B
C
D
(i)
State which of the parts labelle lled A, B, C or D, contai tains iodopsin.
........................... (1)
(ii)
There are three three differen differentt forms forms of iodopsin iodopsin.. State how many many differen differentt forms of iodopsin would be present in the cells shown in the diagram. ......................................................................... ............................................................................................................... .................................................. ............ (1)
(b) (b)
Expl Explai ain n how how rhodopsin is involved in the conversion of light energy into electrical energy. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (4) (Total 6 marks)
30.
Give an account of how a nerve impulse is generated in a post-synaptic neurone following the release of a neurotransmitter.
(Allow two lined pages). (Total 10 marks)
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(a)
31.
Pavlov carried carried out out experiment experimentss on dogs to invest investigate igate classical classical conditionin conditioning. g.
Explain how the dogs became conditioned to salivate at the sound of a bell in Pa vlov’s experiments. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
(b)
Using operant operant condition conditioning, ing, pigeons pigeons were presen presented ted with with coloured coloured keys keys and and taught taught to peck one particular key. Suggest how this operant conditioning was achieved. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(c)
Briefly Briefly discuss discuss the extent extent to which the study study of learning learning in animals animals can help help us us to understand learning in humans. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(d)
Explain Explain how functional functional magnetic magnetic resonan resonance ce imaging imaging (fMRI) (fMRI) can improve improve our knowled knowledge ge of human brain function. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 9 marks)
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32.
The picture below shows the response of a cat’s pupil to bright light.
(a)
(i) Describe how the nervous system controls the pupil reflex in a mammal such as a cat, in response to bright light. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (4)
(ii)
Describe Describe and explain explain how myelin myelination ation of of neurones neurones is is an advanta advantage ge in this this reflex reflex pathway. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (3)
(b)
Hubel and and Weisel Weisel covered covered one one eye of kittens of different ages ages to to investigate investigate the timing of of visual development in mammals. Kittens which had one eye covered from the fourth to the fifth week subsequently had very poor vision in that eye. Kittens which had one eye covered at earlier or lat er times had normal vision. Suggest an explanation for these observations. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
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(c)
Some people people have ethical ethical objection objectionss to animal animal experiments experiments.. Suggest Suggest how how a biolog biologist ist might justify the use of animals in experiments. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 12 marks)
33.
The diagram below shows a human brain seen from the side. (a)
Name Name the parts parts labelle labelled d B and C. B ...................................... .............................................................................. .............................................................................. .................................................... ..............
.................................................................................................................. ........................................................ ................ C .......................................................................... (2)
(b)
Give two functions of the part labelled A. 1 ....................................................................... ............................................................................................................. ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... 2 ....................................................................... ............................................................................................................. ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 4 marks)
34.
State three ways in which hormonal control differs from nervous control. 1 ........................................ .............................................................................. ............................................................................ .............................................................. ........................ ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. 2 ........................................ .............................................................................. ............................................................................ .............................................................. ........................ ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. 3 ........................................ .............................................................................. ............................................................................ .............................................................. ........................ ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. (Total 3 marks)
35.
(a)
When an action action potent potential ial arrives arrives at a synapt synaptic ic knob, knob, acetylcho acetylcholine line is released released..
Describe how acetylcholine is released into the synaptic cleft. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
53
(b)
The graph graph below below shows shows a recordin recording g of an an action action potential potential produc produced ed after after the binding binding of acetylcholine to receptors on a post-synaptic membrane.
+
3
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M p
o
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i m
e
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m
s
Use the graph graph to state state the the time time at which the sodium sodium channels channels open to allow allow an an increased flow of sodium ions into the neurone. .................................................... .................................................... ms (1)
(ii)
Use the the graph graph to state state the time at which which the the hyperpola hyperpolarisatio risation n is at its greatest greatest.. .................................................... .................................................... ms (1)
(iii)
Calculate the number of action potentials that that could occur in one second second if the stimulus is maintained. Show your working.
Answer ....................................... action potentials per second. (2)
(c)
When a transmitte transmitterr substanc substancee called called gamma-a gamma-aminobu minobutyric tyric acid (GABA) (GABA) is released released at a +
synapse, it causes chloride ion (Cl–) channels and potassium ion (K ) channels to open in the post-synaptic membrane. This results in chloride ions moving into the post-synaptic neurone and potassium ions moving out. Explain why an action potential is less likely to develop when GABA is released at the same time as acetylcholine. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 9 marks)
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36.
Detection of light occurs in both mammals and flowering plants. (a)
In humans, humans, the central central region of the the retina retina has has very very few rod cells. cells. However, However, in a dog about 80–90% of the photoreceptors in the central region of the retina are rod cells. Suggest one advantage to a dog of having more rod cells in this region of the retina. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
(b)
G
r a
Humans Humans have three types of cone cone cell. cell. However, However, dogs dogs only only have two types types of cone cone cell. cell. Graph 1 below shows the percentage of light, of different wavelengths, absorbed by the pigments in the two types of cone cell in a dog’s retina. Graph 2 shows the percentage of light, of different wavelengths, absorbed by the pigments in the three types of cone cell in a human’s retina. p
h
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Three balls, that differed only in their colour, were placed in front of a dog and a human. One ball was red, one yellow and one orange. Using this data, explain why only the human would be able to detect a difference between the colour of the t hree balls. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
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(c)
Describe Describe the detection detection of light in flowering flowering plants. plants. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3) (Total 8 marks)
37.
Give an account of the structure and functions of sensory, relay and effector (motor) neurones.
(Allow two lined pages). (Total 10 marks)
38.
The diagram below shows a rod cell from the retina of the human eye.
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The function of rod cells can be affected by the condition known as retinitis pigmentosa. Retinitis pigmentosa causes the gradual breakdown of photoreceptor cells in the retina. As these cells degenerate and die, patients experience progressive loss of vision. One of the most common forms of retinitis pigmentosa can be caused by a recessive allele inherited from parents who have normal vision.
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With reference to the function of rod cells and rhodopsin as photoreceptors, explain why people with retinitis pigmentosa experience progressive loss of vision. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. ........................................................................... ................................................................................................................. .................................................................... .............................. (Total 4 marks)
39.
Research on visual development in cats has led to knowledge of how information is processed in the visual cortex of the brain. The diagrams below show the growth of neurones in part of the visual cortex after normal visual development and when the left eye has been deprived of sensory information. N
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(a)
Use the the diagrams diagrams above to describ describee differenc differences es in the visual visual cortex cortex after after sensory sensory deprivation. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(b)
Explain Explain how this this type type of experiment experiment has has provided provided evidence evidence which which shows shows the the need for for exposure to sensory information in normal visual development. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2)
(c) (c)
Des Describ cribee one other piece of evidence which suggests that humans must be exposed to particular stimuli if they are to develop normal vision. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (1) (Total 5 marks)
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40.
People with Parkinson’s disease have poor control over their skeletal muscles, caused by a lack of the neurotransmitter dopamine. Large numbers of neurones secreting dopamine are found in the basal ganglia region of the brain. Parkinson’s disease can be diagnosed and monitored using brain scans. The fMRI scans below show the results of a study where subjects did a standard finger-tapping activity to investigate the effectiveness of a new drug treatment. The results below are from a healthy brain, a patient with Parkinson’s disease without drug treatment and a patient with Parkinson’s disease taking drug treatment. The scan shows a horizontal section with the front of the head at the top. The m ost active areas are white.
(a)
Using Using the fMRI fMRI scans scans above, above, discus discusss the effects effects of this this new drug drug on brain brain activit activity. y. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
(b)
Explain Explain how how neurotra neurotransmitt nsmitters, ers, such as dopamin dopamine, e, stimula stimulate te neuron neurones. es. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (4)
(c)
People with Parkin Parkinson’s son’s disease disease have have much much less less dopamine dopamine in their their brain brain than than other other people. Using the information already given in this question and your own knowledge, suggest and explain how Parkinson’s disease can be treated using drugs. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (4) (Total 11 marks)
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41. 41.
Answ Answer er the the follo followi wing ng essa essay y que quest stio ion. n.
You are expected to answer in continuous prose. You should use examples from the biology course you have studied but need not restrict yourself to the course content. You are advised to spend approximately 45 minutes answering Question 3 or Question 4, including planning time. Marks will be awarded in the following areas: Breadth: selecting a range of aspects of biology from different parts of your AS and A2 course which are relevant to the question. (up to 6 marks) Depth: developing the aspects you have chosen by including relevant details, examples and (up to 8 marks) discussion. Balance: have you answered the question asked? for example, by dealing with the bigger ideas which lie beneath the wording of the question, such as discussing implications, weighing up benefits and risks, advantages and disadvantages or the extent to which an assertion in the (up to 6 marks) question is or is not valid. Style: coherence, clarity and expression; for example, good use of technical terms, sentences and paragraphs, and weaving together information and ideas clearly to focus on the question. (up to 4 marks)
Our ability to detect and respond to changes in our external and internal environment has enabled humans to survive on all continents and in a wide variety of potentially hazardous situations. Write an essay on: ‘The importance of control and coordination in the body.’ (Total 20 marks)
42.
(a) The table table below below refers refers to three three function functionss of the human human brain. brain. Complete Complete the the table to show which region of the brain is responsible for each function.
Function
Region of the brain
Ability to learn
Thermoregulation
Control of heartbeat (3)
(b)
The diagra diagram m below below shows shows an image produced produced by by an MRI (magne (magnetic tic resonan resonance ce imaging) imaging) scan. The region labelled X is a tumour.
Source: www.medicalprogress.org
Suggest two pieces of information this scan could give to a surgeon about this tumour. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (2) (Total 5 marks)
43.
The diagram below shows the structures of the neurotransmitter, dopamine, and the drug, Ldopa, used in the treatment of Parkinson’s disease.
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With referen reference ce to the the structure structuress of dopamin dopaminee and L-dopa, L-dopa, suggest suggest why the drug drug L-dopa L-dopa is effective in the treatment of Parkinson’s disease. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (4)
(b)
Scientists Scientists believe believe that the the release release of dopamine dopamine from the presyn presynaptic aptic membrane membrane is triggered by certain emotional responses. Describe how the release of this neurotransmitter generates action potentials in the postsynaptic neurone. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (5) (Total 9 marks)
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44.
The retina of a mammal’s eye contains millions of receptor cells which are highly sensitive to light. These receptor cells are protected from excessively bright light by the iris. The diagram below shows part of a nerve cell pathway involved in the reflex controlling the size of the pupil by the iris. (a)
(i) Put a cross in the the box next to the arrow that correctly shows the the direction of impulse travel in cell A.
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Identify Identify the type of neurone neurone for cell A and cell B by putting a cross in the correct box in the table below. Relay neurone
Motor neurone
Sensory neurone
Cell A Cell B (2)
(b)
(i) Complet lete the equatio tion below to show the the chemica ical changes in rhodopsin in the presence of light. rhodopsin + light → opsin + ................................................ ................................................ (1)
(ii)
Describe Describe the the movement movement of sodium sodium ions across across the rod cell cell membran membrane, e, in the presence of opsin. ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ ......................................................................... ............................................................................................................... .................................................. ............ (3)
(iii)
State the term that describes the electrochemical state of a rod cell in light. ......................................................................... ............................................................................................................... .................................................. ............ (1) (Total 8 marks)
45.
Sea slugs are marine invertebrates with gills for gas exchange on their body surface. A sea slug is able to withdraw its gill when touched. In an investigation into this response, the gill was touched and the time taken for the gill to be exposed again after withdrawal was measured. This was repeated at half-minute intervals. The table below shows the results of this investigation. Touch
Time taken for gill to be exposed again / seconds
First
23.0
Second
9.0
Third
16.0
Fourth
4.5
Fifth
7.5
Sixth
6.5
Seventh
6.0
Eighth
4.5 Ninth
Tenth
5.5 6.5
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(a)
Describe Describe the the effect effect of repeated repeated touching touching on the the time taken for the the gill gill to be be exposed exposed again. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (3)
(b)
Name the type of learnin learning g shown shown by a sea slug in this this investi investigation gation.. .......................................................................... ................................................................................................................ ........................................................... ..................... (1)
(c)
Explain Explain how this learned learned response response may be be of benefit benefit to the the sea sea slug in its natural natural environment. .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... .......................................................................... ................................................................................................................ ........................................................... ..................... (4) (Total 8 marks)
