Descripción: In here you will find an assortment of Biology Paper 1 Multiple choice questions on Topic 1 - Statistical Analysis and Topic 2 - Cells. Please note that these are from the old IB Biology syllabu...
In here you will find an assortment of Biology Paper 1 Multiple choice questions on Topic 1 - Statistical Analysis and Topic 2 - Cells. Please note that these are from the old IB Biology …Full description
In here you will find an assortment of Biology Paper 1 Multiple choice questions on Topic 6 - Human Health and Physiology. Please note that these are from the old IB Biology syllabus (First exam...
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Questions Bank for Molecular Biology Answer SheetDescripción completa
This book includes Multiple Choice Questions along with their answers as well as tutorials on each of the questions. The topics covered are: 1. Eukaryotic Gene Expression 2. Nucleic Acids …Full description
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Human & Social Biology cxc questions
General information about biology. Good reviewer for an exam covering general knowledgeFull description
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Questions Bank for Molecular Biology Answer SheetFull description
This book includes Multiple Choice Questions along with their answers as well as tutorials on each of the questions. The topics covered are: 1. Eukaryotic Gene Expression 2. Nucleic Acids …Full description
This book includes Multiple Choice Questions along with their answers as well as tutorials on each of the questions. The topics covered are: 1. Eukaryotic Gene Expression 2. Nucleic Acids 3. Rec...Full description
This book includes Multiple Choice Questions along with their answers as well as tutorials on each of the questions. The topics covered are: 1. Eukaryotic Gene Expression 2. Nucleic Acids …Descripción completa
1.
Zoom Zoom in on the the neur neuron. on. What What prot protei ein n struc structu ture res s are are imb imbed edde ded d in the the membrane?
2.
What substance is there more more of outside the the neuron? What about inside? inside? (Click “Show concentrations” if ou are unsure!.
%.
"
#ut uts sid ide e ar are sod sodiu ium m ion ions s
"
$nsi $n side de ar are e po pota tass ssiu ium m io ions ns
Click “Show char&e” a.
What is the char&e of the inside of the cell? "
b.
What is the char&e of the outside of the cell? "
c.
'e&atie
)ositie
$f *+ *+ and 'a+ ar are bo both positie ie, how mi mi&ht a ne&atie cha charr&e co come about? " -he potassium electrons are are more ne&atie ne&atie than sodium
ions. -hree sodium ions are epelled for eer two potassium ions admitted and some potassium leaks out of the cell. /.
Zoom Zoom out out and and slow slow the the sim sim down down.. Clic Click k “S “Sti timu mula late te neur neuron on”. ”. 0ol 0ol cow cow escribe what ou saw. saw. " " " " "
4.
-he imp impuls ulse e moes moes dow down n the the neur neuron on and and then then the sod sodium ium ions come in and the char&e swap. 3or eer eer % 'a com comin& in& out out,, 2 )o )otas tassiu sium m is let in. -he char&e swa wap ps. -he pr prote otein in chan channel nel &at &ate e opens opens and lets Sod Sodium ium ion The nerve impulse is a result of a change in concentrations of sodium and potassium ions across the membranes of the neuron.
Which wa did 'a+ moe? -hrou&h what did it moe to &et there? there? "
5rriall of an 5rria an actio action n )ote )otenti ntial al caus causes es depo depolari larisat sation ion of of ad6acent sections of the neuron. •
-his causes local 'a+ di7usion and a current.
•
•
b.
$t is more positie than the outside
Which wa did *+ moe? -hrou&h what did it moe to &et there? "
c.
$f the current is enou&h to rise aboe the threshold, the voltage-gated Na+ channel opens and 'a+ rushes in.
* + channels are opened and * + di7uses out. $nternal char&e is ne&atie a&ain (repolarisation!
What was the wae that moed down the neuron? " -he nere impulse. $t is a result of a chan&e in concentration of sodium and potassium ions across the membranes of the neuron. -hese chan&es are called depolarisation and repolarisation.
d.
escribe what happens to the char&e on the inside and outside after the wae passes. "
e.
Can ou stimulate the neuron a&ain ri&ht after 8rin& it? Wh? "
=.
Some potassium ions di7use back out, leain& the outside more positie and inside more ne&atie.
9es : ;efractor period is when the channels rest between openin&s. -his ensures one"wa impolse
Click the button “)otential chart” Stimulate the neuron and draw the resultin& &raph below. a.
What does this &raph show? "
$t shows an increase as the nere impulse reaches the membrane.
b.
>abel “threshold”, “stimulus”, “restin& potential” and “undershoot” on our &raph. ake the title “5ction )otential” "
Resting potential: •
•
;estin& potential is maintained b actie transport
•
Sodium ion is pumped out
•
)otassium ions pumped in
•
"
-he electrical potential across the plasma membrane of a cell that is not conductin& an impulse
Some potassium ions di7use back out, leain& the outside more positie and the inside more ne&atie
Action potential 1. ;estin& potential is maintained b actie transport 2. 5rrial of an aaction potential causes depolisation of ad6acent sections of the neuron. %. -his causes local 'a+ di7usion and a current. /. * + channels are opened and potassium ions di7uses out.
@.
$s there a wa to make the si&nal an stron&er? $s there a wa to make it stron&er in an actual neuron? 'o
A.
What is the melin sheath? (See notes on ri&ht!..oes this simulation hae one?
B.
0ow would the si&nal be di7erent if there was a melin sheath?
"
"
$n some neurons the aon ma be coered b a fatt white substance called melin which functions as an insulatin& laer. elin is a miture of protein and phospholipids that is produced b &lial cells.
"
1.
-he main purpose of elin sheath is to increase the speed of electrical transmissions ia salutator conduction.
0ow is this simulation similar to and di7erent from an actual neuron? a. i7erenceD the actual neuron impulse traels so much Euicker. b. SimialritD the process of di7usion of the ions in and out of the membrane.
11.
0ow does the si&nal trael from one neuron to the net? (not in simulation! "
Signals move across the snapse, the place where the aon of one neuron meets the dendrite of another, usin& chemicals called neurotransmitters
12. Write a %"4 sentence summar eplainin& how a si&nal traels down a neuron, usin& the followin& termsD •
5ction potential
•
'a+
•
*+
•
Channel
•
'euron -hreshold
•
•
elin sheath
•
;estin& potential •
-he transmission of a nere impulse alon& a neuron from one end to the other occurs as a result of electrical chan&es across the membrane of the neuron. -he membrane of an unstimulated neuron is polariFedGthat is, there is a di7erence in electrical char&e between the outside and inside of the membrane. -he inside is ne&atie with respect to the outside.
