BIOLOGY MCQ’S 1.
TayTay-sac sachs hs dis disea ease se res resul ults ts due due to to lack lack of of enzy enzyme me-(a) Glucokinase
1.
2.
(b ) HexosaminidaseA
(c) Pyr uva te ki nas e (c) Na+–K+ ATPase (b) Tay-sa Tay-sachs chs is a diseas diseasee which which begins begins to shows shows neuro neurolog logica icall impair impairme ment nt and psych psychom omoto otorr difficu difficulti lties. es. Tay-sachs disease results form a lack of the enzyme hexosaminidase A and the subsequent st orage of its substrate a glycosphingolipid in lysosomes. Cyst Cystic ic fibr fibros osis is is a dis disea ease se in whic whichh(a) Na +ions fail to pass through plasma membrane (b ) Cl+ ions fail to pass through plasma membrane (c) K+ions fail to pass through plasma membrane (d) (d) (a) (a) and and (b) (b) bot both h
2.
(b) Cystic Cystic fibros fibrosis is is a commo common n lethal lethal gene genetic tic dise disease ase amon among g caucas caucasion ionss in the the unite united d states states.. In this this – lethal disease chloride ions (Cl ) fail to pass through plasma membrane channels in t hese patients.
3.
A pro prom motor otor gene gene defi define ness the the (a) Site Site for initia initiall binding binding of RNA RNA polym polymera erase se (b) Direc Directio tion n of trans transcri cripti ption on
3.
4.
(c) (c) Copy Copyin ing g the the stra strand nd (d) (d) All All of of the the abov abovee (a) When When promo promotor tor gene is turne turned d on by bindi binding ng RNA RNA Polyme Polymeras rasee then then trans transcrip cription tion by stru structur ctural al genes takes place. The post posteri erior or part part of the the retin retinaa which which is just just oppos opposite ite to to the lens lens is is called called (a) Co C o r n ea
(b) Ye Yellow spot
(c) Area centralis
(d ) B and C both
4.
(b) The post posteri erior or part part of the the retin retinaa which which is just just oppo opposit sitee to the the lens lens is calle called d area area centra centralis lis or or yellow yellow spot spot which contains only cones and has yellow pigment, the image are normally focussed on this area.
5.
Urinif Urinifero erous us tubul tubules es poste posterio riorr part part of the the kidne kidney y open open into into the the (a) Vas deferens
5.
6.
6.
7.
7.
(b ) Bidder’s canal
(c) Vesicula seminalis (d ) Wolfian duct (b) From each testis testis several several thin vasa efferenti efferentiaa emerg emergee throug through h the the mesor mesorchium chium end join the urinifero uriniferous us tubules of the posterior part of the kidney to open into the Bidder’s canal of the kidney which turn opens into the ureter. The Bow Bowma mann’ nn’ss capsul capsulee along along with with its its glome glomerul rulus us is calle called d (a) Corpusc Corpuscle le tubul tubules es or Malp Malpighi ighian an body body (b) Dista Distall conv convolu oluted ted tubule tubule (c) Semi Semini nife fero rous us tubu tubule le (d) Urin Urinif ifero erous us tubu tubule le (a) The Bowm Bowman’ an’ss capsul capsulee along along with with its its glome glomerul rulus us is call called ed malpi malpighi ghian an body body or corp corpusc uscle le tubul tubulee then then opens into the collecting tubule which finally opens into the ureter. Which Which one is corr correct ect about about auto autonom nomic ic nerv nervous ous system system (a) It is partly partly indepen independent dent and and not under under volunta voluntary ry control control (b) It is partly independent independent and not under under involuntary involuntary control (c) It is fully independent independent and and not not under under involuntary involuntary control (d) It is fully fully depende dependent nt and and not under under volunta voluntary ry control control (a) Pancreat Pancreatic ic juice juice is a water watery y alkal alkaline ine fluid fluid conta containin ining g three three powerfu powerfull enzym enzymes es calle called d tryps trypsinog inogen, en, amylopsin, trypsin
8.
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9.
9.
10.
Interphase (a) Is the same as prophase, metaphase anaphase and telophase (b) Include stages G1, S and G2 (c) Requires the use of polar fibres and kinetochore fibres (d) Rarely occurs (b) Interphase is a resting stage of the cell. It includes G1, S and G2 stages. During the G1 stage the cell grows in size and the cellular organelles increase in number. During the G2 stage various metablolic events occur in preparation for mitosis. S is the synthetic phase. In which phase of mitosis the chromosome move forward the poles ? (a) Prophase (b) Metaphase (c) Telophase (d) Anaphase (d) At the start of anaphase, the centromere of each duplicated chromosome divides. Daughter chromosomes each with a centromere and single chromatid, begin to move toward opposite poles. Electron transport system is located in (a) Mitochondrial matrix (b) Cytosol (c)
Cristae
10.
(d) All of the above (c) The electron transport system is located in the cristae of the mitochondria is a series of carriers that pass electrons from one to the other.
11.
Which one is correct about glycolysis? (a)
Breakdown of glucose to two molecules of pyruvate
(b) Occurs in cytoplasm (c) Two NAD+accept two electrons and become NADH 11.
12.
(d) All of the above (d) Glycolysis is the breakdown of glucose to two molecules of pyruvate. This pathway is a series of enzymatic reactions that occur in the cytosol. Two NAD+ accepts two electrons and become NADH. Then substrate level phosphorylation produces a net gain of two ATP molecules. The NADH either gives electrons to pyruvate or takes them to mitochondria. A phosphate bond contains an energy : (a) 7.3 k cal (c) 10 k cal
(a) 8.3 k cal (a) 11.7 k cal
12.
(a) An ATP phosphate bond has energy content of 7.3 k cal, and 36 of these are produced during glucose breakdown. 36 phosphates are equivalent to a total of 263 k cal.
13.
In anaerobic respiration the process takes place is : (a)
Kreb’s cycle
(b) Glycolysis (c) Oxidative phosphorylation 13.
(d) Glycolysis and Kreb’s cycle (b) During fermentation, the hydrogen atoms are generated by glycolysis and NAD+ is regenerated to obtain ATP. Certain animal cell, deprived of oxygen, temporarily carry out lactic acid fermentation.
14.
Most of the energy during aerobic respiration is produced by the (a) Electron transport chain (b) Glycolysin (c)
Kreb’s cycle
(d) Oxidative phosphorylation 14.
(a) Most of the energy harvested during aerobic respiration is produced by the electron transport chain. In total the oxidation of one molecule of glucose results in the net production of 36 ATP molecules.
15.
Estuaries formed where (a) Fresh water meets sea water (b) Marine water meets lake water (c) River water meets lake water
15.
(d) Fresh water meets lake water (a) Estuaries occur where fresh water meets sea water and the salinity of sea water is diluted.
16.
In the sexual reproduction of Spirogyra, the cell contents contract from cell walls to form (a) The zoospores
(b) The zygospores
(c) The gametophytes
(d) The gametes
16.
(d) The sexual reproduction in Spirogyra is called conjugation. The cell contents taking part in development of gametangia become separated from the cell wall and shrink and ultimately are converted into gametes. The fusion of t hese gametes results into the formation of zygospore.
17.
Sexual reproduction is found in all the classes of algae except (a) Cyanophyceae (c) Rhodophyceae
(b) Chlorophyceae (d) Phaeophyceae
17.
(a) In cyanophyceae reproduction takes place by vegetative and asexual methods. Vegetative reproduction takes place by cell division, fragmentation and hormogonia formation. Asexual reproduction is by akinetes, endospores, exospores, heterocysts and nannocysts.
18.
All algae have (two pigments-common in all-groups of algae)(a) Chlorophyll a and chlorophyll b (b) Chlorophyll b and carotenes (c) Chlorophyll a and carotenes (d) Phycobilin b and carotenes
18.
(c) There are five types of chlorophylls, viz., chl. a, b, c, d, and e. Of these chlorophyll a is present in all groups of algae. Similarly, carotenes are also of five types, i.e.,α-carotene, β-carotene, γ -carotene, Ecarotene and flavacene. At least one of them is present in all the members of algae.
19.
Diplanetism is exhibited by(a) Saprolegnia
19.
(b) Rhizopus (d) Vaucheria
(c) Ulothrix (a) In Saprolegnia , asexual reproduction takes place by zoospores which are produced in zoosporangium. These zoospores are pearshaped, biflagellate and are known asprimary zoospores . The zoospores withdraw their flagella and secrete a thick wall. These resting zoospores are termed asprimary cysts. During favourable conditions, the cysts germinate and produce biflagellate kidney shapedsecondary zoospores, which produce new mycelia on germination.This phenomenon of the production of two types of zoospores (primary and secondary ) is know as diplanetism and these zoospores as diplanetic.
20.
Which one of the following fixes CO2 into carbohydrates ? (a) Rhizobium (b) Bacillus (c) Nitrobacter (d) Rhodospirillium
20.
(d) Rhodospirillum is a non sulphur bacteria utilizes non sulphur compound like alcohol, organic acid for as hydrogen donor for CO2 fixation.
21.
The ferns, in which the entire sporangium develops from a single superficial cell of the sporophyll is known as (a) Leptosporangiate (c) Unisporangiate
21.
(b) Eusporangiate (d) Mesosporangiate
(a) Two types of sporangia are formed in the vascular plants. In case of eusporangiate development, the sporangium develops from a superficial group of parent initials, while leptosporangiate sporangium originates from a single superficial parent initial.
22.
Cell A has osmotic potential of - 16 bars and pressure potential of 8 bars, whereas cell B has osmotic potential of- 12 bars and pressure potential 2 bars. The direction of flow of water will be (a) From cell B to cell A (b) From cell A to cell B (c)
22.
No flow of water
(d) In both the directions
( b) The water potential (ψ ) is equal to osmotic potential (ψ s) + pressure potential ( ψ p). Osmotic potential is always in negative value. The water potential is the chemical potential of water which is equivalent to DPD with negative sign. Therefore, Water potential( ψ ) of cell A = ψ s + ψ p = – 16 + 8 = –8 Water potential ( ψ ) of cell B
= ψ s + ψ p = –12 +2 = –10 Since water moves from higher water potential to lower water potential, the flow of water will be fr om cell A (–8 bars) to cell B (–10 bars ). 23.
Linear sori and false indusium are characteristics of (a) Pteris (b) Dryopteris (c) Polypodium (d) Adiantum
23.
(a)
24.
Fruits are not formed in gymnospermous plants because(a)
In Pteridium, the sporangia are borne on certain leaves of the mature plant, which are called the sporophylls. They are not group ed together in small sori but the sorus is conti nuous along the under margin of the pinnules for considerable distances. This type of sorus is known as continuouslinear sorus (coenosorus). The coenosorus is surrounded by two well formed indusial lips, outer and inner. The outer indusial lip is well developed and formed by the reflexed margin of the pinnule which overlaps the coenosorus and its sporangia.This is commonly called thefalse indusium. In Pteris, the sorus is similar to Pteridium but it is protected only by the false indusium
They have no ovary
(b) They are not pollinated (c) 24.
25.
They are seedless plants
(d) Process of fertilization does not take place (a) The fruit is a ripened ovary. After syngamy its ovule is changed into the seed and the ovary wall into the pericarp. In gymnosperms. However, only naked-ovules are present on the megasporophyll. The ovary wall is absent and therefore, only seed is pro duced. The wood of Cycas is (a)
Diploxylic
(b) Monoxylic and manoxylic (c) Manoxylic and polyxylic (d) Monoxylic The stem of C ycas shows normal secondary growth in early stages. Interfascicular and intrafascicular cambium strips join together and form a cambium ring which gives rise to secondary phloem and secondary xylem. The successive zones of secondary xylem and phloem alternating with parenchymatous tissue are formed. This type of condition is called polyxylic condition (polycyclic). At large amount of parenchymatous cells are interspersed with the secondary xylem. The wood is called manoxylic wood (soft wood).
25.
(c)
26.
Wings in Pinus seeds develop from (a)
26.
Seed coat
(b) Bract scales
(c) Ovuliferous scale (d) Cone axis (c) In gymnosperms (e.g.,Pinus ), the ovule is transformed into seed. The outer fleshy layer of ovule wall disappears and the inner fleshy layer remains in the form of a thin membrane. The middle stony layer develops into seed coat. A thin layer of the vent ral surface of the ovuliferous scale is a ttached to the seed and thus the seed becomes winged. This helps in the dispersal of the seed .
27.
The resin duct of a gymnospermous stem is an example of (a) Intercellular space
(b) Schizogenous cavity
(c) Lysigenous cavity
(d) Big vacuole
27.
(b) The young cells are closely packed and there are no spaces between them. As the cells grow, either their walls separate apart from one another or some cells are destoryed at some places, due to which cavities are formed between the cells. If cavities are formed due to separation of cells from one another, are called schizogenous cavities, e.g., Resin canals in Pinus.
28.
The ovules of Cycas are (a) Orthotropous and unitegmic
(b) Orthotropous and tritegmic
(c) Anatropous and unitegmic
(d) Anatropous and tritegmic
28.
(a) The ovules of Cycas are erect. The micropyle, chalaza and funicle lie in one straight line. Such ovules are termed as orthotoropous . The main body of ovule is nucellus covered over by a single thick integument (unitegmic) except at the apex of ovule, which forms micropyle.
29.
Perisperm is (a) Surviving nucleus in the seed
(b) Outgrowth of the outer integument
(c) Outgrowth of funiculus
(d) Both (b) and (c)
29.
(a) In pinus, along with embryo development, various parts of the ovule, outside the female gametophyte (endosperm), undergo several changes by which the ovule is transformed into seed. Due to the growth of endosperm, most of the nucellus is absorbed by the endosperm itself, as it supplies nutrition to it, and the remaining part of the nucellus is pressed towards outside (towards integument) and persist only in the form of a thin brownish layer known asperisperm.
30.
Soil particles arranged in order of increasing sizes are
30.
(a) Clay, silt & sand
(b) Clay, sand and silt
(b) Silt, sand & clay
(d) Sand, silt and clay
(a) The ‘International Society of Soil Science’ has fixed different names for particles of different sizes Name of particles
Diameter
Gravel
5.000 mm
Fine Gravel
2.000 mm
Coarse Sand
0.200 mm
Fine Sand
0.020 mm
Silt
0.002 mm
Clay
Less than 0.002 mm
The relative proportion of the above particles determine the texture of the soil. 31.
Root cap is formed from (a) Fascicular cambium
(b) Calyptrogen
(c) Wound cambium
(d) Protoderm
31.
(b) The root-cap normally arises from thefourth histogen, which is known as the Calyptrogen.
32.
Which of the following is a macronutrient ? (a) Manganese
(b) Copper
(c) Magnesium
(d) Zinc
32.
(c) Out of so many elements present in the plant body Sachs (1860) and Knop (1865) suggested that elements like C, H, O, N, P, K, S, Ca, Mg and Fe are absolutely essential for the growth of the plant and they are required in larger amount. These elements are calledmacroelements or macronutrients.
33.
The primary acceptor of CO2 in C3 plants is (a) Pyruvic acid
(b) PEP
(c) RuBP
(d) AT
33.
(c)
T he s tu di es c on du ct ed o nChlorella and Scenedesmus with the help of radioactive tracer technique by Calvin and coworkers (1954) revealed that the initial acceptor of CO2 in C3 plants is a 5- carbon compound Ribulose -1, 5 -biphosphate (RuBP.)
34.
Essential oils are those which (a) Are essential to the plant itself (b) Are used as lubricants (c)
Produce perfumes
(d) Are essential for human beings Essential oils -These are volatile oils and possess strong aromatic smell.
34.
(c)
35.
Cytochromes are found in (a) Matrix of mitochondria (c) Lysosomes
(b) Cristae of mitochondria (d) Outer wall of mitochondria
35.
(b) A mitochondria consists of two membranes, an outer membrane and an inner membrane. The inner membrane or cristae contains electron carrier molecules (cytochromes), succinic dehydrogenase, ATP-synthetase etc.
36.
Single stranded DNA is found in
36.
(a)
Coliphage φ × 174 virus
(b) Reovirus
(c)
Wound tumor virus
(d) TMV
(a)
Normally DNA has a double helical structure with two poly nucleotide chains connected by hydrogen bonds and running in opposite directions. However, in coliphage φ × 174 virus it is found to be only single stranded, i.e., composed of only one polypeptide chain.
37.
Lysosomes are the (a)
Digestive centres
(b) Respiratory centres
(c)
Excretory centres
(d) Energy centres
37.
(a) Lysosomes were first observed by De Duve. The process of digestion is carried out within the lysosome and digest most of the biological substances. If lysosomes are injured by a toxic substance the whole cell, hence lysosomes are called‘Suicidal bags’, due to the presence of hydrolytic enzymes.
38.
Diploxylic vascular bundles are found in(a) (c)
Pteris Funaria
(b) Selaginella (d) Cycas
38.
(d) In the midrib of C ycas leaflet a large vascular bundle is present. It is collateral and closed. The xylem is mesarch, collateral having centripetal xylem with metaxylem and protoxylem above and two patches of centrifugal xylem on each side of protoxylem of centripetal xylem. Such an arrangement of centripetal and centrifugal xylem is called diploxylic condition.
39.
Neo-Darwinism was given by (a) Charles Darwin
(b) Hugo de vries
(c)
Dobzansky
(d) Wagner
39.
(c)
Modern concept of evolution is a modification of Darwin’s theroy of natural selection by replacing favourable variations with genetic variation or mutation. It is often called Neo-Darwinism or synthetic theory. Some of the important workers, who have contributed to the modernsynthetic theory or NeoDarwinism are Dobzansky, Fisher, Haldane, Sewall Wright Mayer and Stebbins.
40.
DNA replication is (a)
Continuous and conservative
(b) Discontinuous and semiconservative (c) Semidiscontinuous and semiconservative (d) Conservative and semidiscontinuous
40.
(c) Evidences prove that DNA replication issemi-conservative type. At the same time it is also found to be semi-discontinuous, because leading strand is synthesized continuously, while LAGGING STRAND discontinuously. Therefore, the replication of DNA molecule is semi-conservative as well as semidiscontinuous.
41.
Which of the following is called amber ? (a) AUG
(b) UAA
(c) UAG
(d) UGA
41.
(c) Out of 64 possible triplets of genetic code, three codons, namely UAA, UAG and UGA are designated as termination codons . Till the function of these codons was disc overed, they were called nonsense codons, since they did not code for any of the 20 essential amino acids. These three termination codons, viz., UAA, UAG and UGA are k nown as Ochre, Amber and Opal respectively.
42.
Initiation of polypeptide chain in protein synthesis is induced by
42.
(a) Methionine
(b) Glycine
(c)
(d) Lysine
Leucine
(a) The initiation of polypeptide chain in prokaryotes is always brought about by the amino acid methionine, which is coded by the codon AUG as the initiation codon. In E. coli, there are two tRNA’s for mention (i)
t − RNA met m (non formylatable) deposits methionine at the interealary positions and
(ii)
(formylatable) deposits methionine as the first amino acid. In eukaryotes there is t − RNA met f only one type of t-RNA depositing methionine as the first amino acid and also at the intercalary positions.
43.
43.
Which of the following is a test cross ? (a)
Tt × Tt
(b)
Tt × tt
(c)
Tt × TT
(d)
TT× tt
(b) The cross, in which the F1 hybrid is crossed back with its recessive parent, is called a test cross. Test Cross Tt
×
F1hybrid
tt
Recessive parent
Back crosses :
(i) (ii)
44.
Tt
×
F1hybrid Tt
F1hybrid
tt
Recessive parent ×
TT
Dominant parent
In soil, water available for plants is (a) Capillary water
(b) Hygroscopic water
(c) Gravitational water
(d) Chemical bound water
44.
(a) Part of the rain water is held in the soil spaces, which is called capillary water.
45.
Velamen is needed for (a) Respiration of plants
(b) Protection of tissue
(c) Absorption of moisture
(d) None of the above
45.
(c) Velamen is the outermost tissue of the root. The cells of this tissue are large, closely packed with fibrous thickenings. These are dead cells filled with air in dry season and during rains, they absorb water and moisture from surrounding atmosphere.
46.
Linnaeus gave a system of nomenclature called(a)
Binomial
(b) Artificial system
(c)
Natural system
(d) Phylogenetic system
46.
(a) Carouls Linnaeus (1707-1778) , who is rightly known as“Father of Modern Botany “ published a number of books . His “Species Plantarum “ was published in 1753, in which he introduced the consistent use of the binomial system of plant name , i.e., the name of a species consists of the name of the genus followed by the specific epithet.
47.
Exchange of segments between non-homologous chromosomes is called (a) Inversion (b) Duplication (c) Translocation (d) Deletion
47.
(c)
Translocations are the chrmosomal abberations, responsible for unilateral or bilateral transfer of chromosome segments from one chromosome to another. The segmental interchanges involving mutual exchange of chromosome segments between two pairs of non-homologous chromosomomes are known as reciprocal translocations.
