NEET Phase-I Biology solution
Code – X
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- The two polypeptides of human insulin are linked together by:
- Phosphodiester bond
- Disulphide bridges
- Hydrogen bonds
Ans. (3) Disulphide bridges [NCERT class 12, page 211]
- The coconut water from tender coconut represents :
- Fleshy mesocarp
- Free nuclear proembryo
- Free nuclear endosperm
Ans. (3) Free nuclear endosperm [NCERT class 12, page 35]
- Which of the following is not a feature of the plasmids ?
- Circular structure
- Single – stranded
- Independent replication
Ans. (3) Single – stranded [NCERT class 12, page 194]
- Which is the National Aquatic Animal of India?
- River dolphin
- Blue whale
- Gangetic shark
Ans. (1) River dolphin
- The Avena curvature is used for bioassay of:
Ans. (2) IAA
- Which of the following is the most important cause of animals and plants being driven to extinction?
- Alien species invasion
- Habitat loss and fragmentation
- Co – extinctions
- Over – exploitation
Ans. (2) Habitat loss and fragmentation [NCERT class 12, page 264]
- Which of the following approaches does not give the defined action of contraceptive?
|(1)||Intra uterine devices||increase phagocytosis of sperms, suppress sperm motility and fertilizing capacity of sperms|
|(2)||Hormonal contraceptives||Prevent/retard entry of sperms, prevent ovulation and fertilization|
|(4)||Barrier methods||prevent fertilization|
Ans. (3) Vasectomy – prevent spermatogenesis. [NCERT class 12, page 59-62]
- In a testcross involving dihybrid flies, more parental-type offspring were produced than the recombinant-type offspring. This indicates:
- Chromosomes failed to separate during meiosis.
- The two genes are linked and present on the same chromosome.
- Both of the characters are controlled by more than one gene.
- The two genes are located on two different chromosomes.
Ans. (2) The two genes are linked and present on the same chromosome. [NCERT class 12, page 83]
- A typical fat molecule is made up of:
- One glycerol and three fatty acid molecules
- One glycerol and one fatty acid molecule
- Three glycerol and three fatty acid molecules
- Three glycerol molecules and one fatty acid molecule
Ans. (1) One glycerol and three fatty acid molecules [NCERT class 11, page 145, Fig.9.1]
- Match the terms in Column I with their description in Column II and choose the correct option:
Column I Column II
(a) Dominance (i) Many genes govern a single character
(b) Codominance (ii) In a heterozygous organism only one allele expresses itself
(c) Pleiotropy (iii) In a heterozygous organism both alleles express themselves fully
(d) Polygenic (iv) A single gene influences inheritancemany characters
(a) (b) (c) (d)
- (ii) (iii) (iv) (i)
- (iv) (i) (ii) (iii)
- (iv) (iii) (i) (ii)
- (ii) (i) (iv) (iii)
Ans. (1) a-(ii) b-(iii) c-(iv) d-(i)
- Which of the following statements is not correct?
- Insects that consume pollen or nectar without bringing about pollination are called pollen/nectar robbers.
- Pollen germination and pollen tube growth are regulated by chemical components of pollen interacting with those of the pistil.
- Some reptiles have also been reported as pollinators in some plant species.
- Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style.
Ans (4) Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style. [NCERT class 12, page 30,31,32]
- Which of the following features is not present in Periplaneta americana?
- Indeterminate and radial cleavage during embryonic development
- Exoskeleton composed of N-acetylglucosamine
- Metamerically segmented body
- Schizocoelom as body cavity
Ans (1) Indeterminate and radial cleavage during embryonic development.
58.Water soluble pigments found in plant cell vacuoles are:
Ans (3) Anthocyanins.
59.A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of chromosomes as compared to other dividing cells. This would result in:
- Somaclonal variation
Ans. (1) Polyploidy
60.A plant in your garden avoids photorespiratory losses, has improved water use efficiency, shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilisation. In which of the following physiological groups would you assign this plant?
- Nitrogen fixer
Ans. (1) C4
61.In higher vertebrates, the immune system can distinguish self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to:
- Graft rejection
- Auto-immune disease
- Active immunity
- Allergic response
Ans. (2) Auto-immune disease [NCERT class 12, page 153]
62.Emerson’s enhancement effect and Red drop have been instrumental in the discovery of:
- Two photosystems operating simultaneously
- Photophosphorylation and cyclic electron transport
- Oxidative phosphorylation
- Photophosphorylation and non-cyclic electron transport
Ans. (1) Two photosystems operating simultaneously
63.Select the correct statement:
- Salvinia, Ginkgo and Pinus all are gymnosperms
- Sequoia is one of the tallest trees
- The leaves of gymnosperms are not well adapted to extremes of climate
- Gymnosperms are both homosporous and heterosporous
Ans. (2) Sequoia is one of the tallest trees [NCERT class 11, page 39]
64. Which of the following is not a characteristic feature during mitosis in somatic cells?
- Disappearance of nucleolus
- Chromosome movement
- Spindle fibres
Ans. (3) Synapsis [NCERT class 11, page 168]
65. Blood pressure in the pulmonary artery is:
- more than that in the carotid.
- more than that in the pulmonary vein.
- less than that in the venae cavae.
- same as that in the aorta.
Ans. (2) more than that in the pulmonary vein.
66. Which of the following structures is homologus to the wing of a bird?
- Wing of a Moth
- Hind limb of Rabbit
- Flipper of Whale
- Dorsal fin of a Shark
Ans. (3) Flipper of whale.
67. Seed formation without fertilization in flowering plants involves the process of:
- Somatic hybridization
Ans. (3) Apomixis [NCERT class 12, page 38]
68. Name the chronic respiratory disorder caused mainly by cigarette smoking:
- Respiratory acidosis
- Respiratory alkalosis
Ans. (4) Emphysema [NCERT class 11, page 275]
69. Spindle fibres attach on to:
- Kinetochore of the chromosome
- Centromere of the chromosome
- Kinetosome of the chromosome
- Telomere of the chromosome
Ans. (1) Kinetochore of the chromosome [NCERT class 11, page 165]
70. In context of Amniocentesis, which of the following statement is incorrect?
- It is used for prenatal sex determination.
- It can be used for detection of Down syndrome.
- It can be used for detection of Cleft palate.
- It is usually done when a woman is between 14 -16 weeks pregnant.
Ans. (3) It can be used for detection of Cleft palate.
71. Stems modified into flat green organs performing the functions of leaves are known as:
Ans. (2) Phylloclade.
72. In a chloroplast the highest number of protons are found in:
- Lumen of thylakoids
- Inter membrane space
- Antennae complex
Ans. (1) Lumen of thylakoids [NCERT class 11, page 213]
73. Nomenclature is governed by certain universal rules. Which one of the following is contrary to the rules of nomenclature?
- The first word in a biological name represents the genus name, and the second is a specific epithet
- The names are written in Latin and are italicised
- When written by hand, the names are to be underlined
- Biological names can be written in any language
Ans. (4) Biological names can be written in any language [NCERT class 11, page 7]
74. In meiosis crossing over is initiated at:
Ans. (4) Pachytene
75. Antivenom injection contains preformed antibodies while polio drops that are administered into the body contain:
- Harvested antibodies
- Gamma globulin
- Attenuated pathogens
- Activated pathogens
Ans. (3) Attenuated pathogens
76. The taq polymerase enzyme is obtained from:
- Thiobacillus ferroxidans
- Bacillus subtilis
- Pseudomonas putida
- Thermus aquaticus
Ans. (4) Thermus aquaticus [NCERT class 12, page 203]
- Which of the following most appropriately describes haemophilia?
- X-linked recessive gene disorder
- Chromosomal disorder
- Dominant gene disorder
- Recessive gene disorder
Ans. (1) X-linked recessive gene disorder [NCERT class 12, page 89]
- The standard petal of a papilionaceous corolla is also called:
Ans. (2) vexillum [NCERT class 11, page 74]
- Which part of the tobacco plant is infected by Meloidogyne incognita ?
Ans. (3) Root
- Which of the following statements is wrong foi viroids ?
- They are smaller than viruses
- They cause infections
- Their RNA is of high molecular weight
- They lack a protein coat
Ans. (3) Their RNA is of high molecular weight [NCERT class 11, page 27]
81. Which of the following statements is not true for cancer cells in relation to mutations?
- Mutations destroy telomerase inhibitor.
- Mutations inactivate the cell control.
- Mutations inhibit production of telomerase.
- Mutations in proto-oncogenes accelerate the cell cycle.
Ans. (3) Mutations inhibit production of telomerase.
82. Which type of tissue correctly matches with its location?
- Areolar tissue Tendons
- Transitional epithelium Tip of nose
- Cuboidal epithelium Lining of stomach
- Smooth muscle Wall of intestine
Ans. (4) Smooth muscle Wall of intestine [NCERT class 11, page 101,103,105]
83. Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other?
- Insulin – Glucagon
- Aldosterone – Atrial Natriuretic Factor
- Relaxin – Inhibin
- Parathormone – Calcitonin
Ans. (3) Relaxin – Inhibin
84. Specialised epidermal cells surrounding the guard cells are called:
- Subsidiary cells
- Complementary cells
Ans. (1) Subsidiary cells [NCERT class 11, page 89]
85. Fertilization in humans is practically feasible only if:
- the ovum and sperms are transported simultaneously to ampullary – isthmic junction of the fallopian tube.
- the ovum and sperms are transported simultaneously to ampullary – isthmic junction of the cervix.
- the sperms are transported into cervix within 48 hrs of release of ovum in uterus.
- the sperms are transported into vagina just after the release of ovum in fallopian tube.
Ans. (1) the ovum and sperms are transported simultaneously to ampullary – isthmic junction of the fallopian tube. [NCERT class 12, page 51]
86. Which one of the following is the starter codon?
Ans. (4) AUG [NCERT class 12, page 112]
87. A river with an inflow of domestic sewage rich in organic waste may result in:
- Increased population of aquatic food web organisms.
- An increased production of fish due to biodegradable nutrients.
- Death of fish due to lack of oxygen.
- Drying of the river very soon due to algal bloom.
Ans. (3) Death of fish due to lack of oxygen. [NCERT class 12, page 275]
88. Following are the two statements regarding the origin of life:
(a) The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
(b) autotrophic organisms were the chemoautotrophs that never released oxygen.
Of the above statements which one of the following options is correct ?
- (b) is correct but (a) is false.
- Both (a) and (b) are correct.
- Both (a) and (b) are false.
- (a) is correct but (b) is false.
Ans. (2) Both (a) and (b) are correct.
- A system of rotating crops with legume or grass pasture to improve soil structure and fertility is called:
- Contour fanning
- Strip farming
- Shifting agriculture
- Ley farming
Ans. (4) Ley farming
- Gause’s principle of competitive exclusion states that:
- Competition for the same resources excludes species having different food preferences
- No two species can occupy the same niche indefinitely for the same limiting resources.
- Larger organisms exclude smaller ones through competition.
- More abundant species will exclude the less abundant species through competition.
Ans. (2) No two species can occupy the same niche indefinitely for the same limiting resources. [NCERT class 12, page 235]
- Which of the following characteristic features always holds true for the corresponding group of animals?
|(2)||Possess a mouth with an upper and a lower jaw||Chordata|
|(3)||3 – chambered heart with one incompletely divided ventricle||Reptilia|
Ans. (4) Cartilaginous endoskeleton – Chondrichthyes
- Changes in GnRH pulse frequency in females is controlled by circulating levels of:
- estrogen and inhibin
- progesterone only
- progesterone and inhibin
- estrogen and progesterone
Ans. (4) estrogen and progesterone
- Microtubules are the constituents of:
- Spindle fibres, Centrioles and Cilia
- Centrioles, Spindle fibres and Chromatin
- Centrosome, Nucleosome and Centrioles
- Cilia, Flagella and Peroxisomes
Ans. (1) Spindle fibres, Centrioles and Cilia [NCERT class 11, page 137,164]
- Mitochondria and chloroplast are:
(a) semi-autonomous organelles.
(b) formed by division of pre-existing organelles and they contain DNA but lack protein synthesizing machinery.
Which one of the following options is correct ?
- (b) is true but (a) is false.
- (a) is true but (b) is false.
- Both (a) and (b) are false.
- Both (a) and (b) are correct.
Ans. (2) (a) is true but (b) is false.
- Photosensitive compound in human eye is made up of:
- Opsin and Retinal
- Opsin and Retinol
- Transducin and Retinene
- Guanosine and Retinol
Ans. (1) Opsin and Retinal [NCERT class 11, page 324]
96. Chrysophytes, Euglenoids, Dinoflagellates and Slime moulds are included in the kingdom:
Ans. (1) Protista [NCERT class 11, page 20]
97. The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, include the:
Ans. (2) Methanogens [NCERT class 11, page 19]
98. Identify the correct statement on ‘inhibin’:
- Is produced by granulose cells in ovary and inhibits the secretion of FSH.
- Is produced by granulose cells in ovary and inhibits the secretion of LH.
- Is produced by nurse cells in testes and inhibits the secretion of LH.
- Inhibits the secretion of LH, FSH and Prolactin.
Ans. (1) Is produced by granulose cells in ovary and inhibits the secretion of FSH.
99. It is much easier for a small animal to run uphill than for a large animal, because:
- Smaller animals have a higher metabolic rate.
- Small animals have a lower O2
- The efficiency of muscles in large animals is less than in the small animals.
- It is easier to carry a small body weight.
Ans. (1) Smaller animals have a higher metabolic rate.
100. A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F1 plants were selfed the resulting genotypes were in the ratio of:
- 1:2:1:: Tall heterozygous: Tall homozygous : Dwarf
- 3:1:: Tall: Dwarf
- 3:1:: Dwarf: Tall
- 1:2:1:: Tall homozygous: Tall heterozygous : Dwarf
Ans. (4) 1:2:1:: Tall homozygous: Tall heterozygous : Dwarf [NCERT class 12, page 74]
101.Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers:
- Nitrous oxide
Ans. (1) Ozone [NCERT class 12, page 283]
102.Which one of the following is a characteristic feature of cropland ecosystem?
- Least genetic diversity
- Absence of weeds
- Ecological succession
- Absence of soil organisms
Ans. (1) Least genetic diversity
103.Tricarpellary, syncarpous gynoecium is found in flowers of:
Ans. (4) Liliaceae [NCERT class 11, page 81]
104.In which of the following, all three are macronutrients?
- Iron, copper, molybdenum
- Molybdenum, magnesium, manganese
- Nitrogen, nickel, phosphorus
- Boron, zinc, manganese
Ans. (Bonus) [NCERT class 11, page 196]
105. Reduction in pH of blood will:
- reduce the blood supply to the brain.
- decrease the affinity of hemoglobin with oxygen.
- release bicarbonate ions by the liver.
- reduce the rate of heart beat.
Ans. (2) decrease the affinity of hemoglobin with oxygen [NCERT class 11, page 274]
106. Lack of relaxation between successive stimuli in sustained muscle contraction is known as:
Ans. (2) Tetanus
107. Which one of the following statements is wrong?
- Golden algae are also called desmids.
- Eubacteria are also called false bacteria.
- Phycomycetes are also called algal fungi.
- Cyanobacteria are also called blue-green algae.
Ans. (2) Eubacteria are also called false bacteria. [NCERT class 11, page 19, 20]
108. Which of the following is a restriction endonuclease?
- DNase I
- Hind II
Ans. (4) Hind II [NCERT class 12, page 195]
- Which of the following would appear as the pioneer organisms on bare rocks?
- Green algae
Ans. (4) Lichens [NCERT class 12, page 251]
- Water vapour comes out from the plant leaf through the stomatal opening. Through the same stomatal opening carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using one of following options:
- Both processes can happen together because the diffusion coefficient of water and CO2 is different.
- The above processes happen only during night time.
- One process occurs during day time, and the other at night.
- Both processes cannot happen simultaneously.
Ans. (1) Both processes can happen together because the diffusion coefficient of water and CO2 is different.
- Cotyledon of maize grain is called:
Ans. (3) Scutellum [NCERT class 11, page 77]
- Which of the following guards the opening of hepatopancreatic duct into the duodenum?
- Ileocaecal valve
- Pyloric sphincter
- Sphincter of Oddi
- Semilunar valve
Ans. (3) Sphincter of Oddi [NCERT class 11, page 261]
- In the stomach, gastric acid is secreted by the:
- parietal cells
- peptic cells
- acidic cells
- gastrin secreting cells
Ans. (1) parietal cells [NCERT class 11, page 262]
- In mammals, which blood vessel would normally carry largest amount of urea?
- Dorsal Aorta
- Hepatic Vein
- Hepatic Portal Vein
- Renal Vein
Ans. (2) Hepatic vein
115. The term ecosystem was coined by:
- A. G. Tansley
- P. Odum
Ans. (1) A.G. Tansley
116. Which of the following is required as inducer(s) for the expression of Lac operon?
- lactose and galactose
Ans. (2) lactose [NCERT class 12, page 117]
117. Which of the following is wrongly matched in the given table?
|(1)||Monascus purpureus||Statins||lowering of blood cholesterol|
|(2)||Streptococcus||Streptokinase||removal of clot from blood vessel|
|(3)||Clostridium butylicum||Lipase||removal of oil stains|
|(4)||Trichoderma polysporum||Cyclosporin A||immunosuppressive drug|
Ans. (3) Clostridium butylicum – Lipase – removal of oil stains [NCERT class 12, page 183]
118. When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as dN/dt = rN(l-N/K):
- when N nears the carrying capacity of the habitat.
- when N/ K equals zero.
- when death rate is greater than birth rate.
- when N/K is exactly one.
Ans. (4) when N/K is exactly one. [NCERT class 12, page 231]
119. Which one of the following statements is not true ?
- Exine of pollen grains is made up of sporopollenin
- Pollen grains of many species cause severe allergies
- Stored pollen in liquid nitrogen can be used in the crop breeding programmes
- Tapetum helps in the dehiscence of anther.
Ans. (4) Tapetum helps in the dehiscence of anther. [NCERT class 12, page 21-23]
120. In bryophytes and pteridophytes, transport of male gametes requires:
Ans. (3) Water [NCERT class 11, page 35-36]
121. Which of the following is not a stem modification ?
- Thorns of citrus
- Tendrils of cucumber
- Flattened structures of Opuntia
- Pitcher of Nepenthes
Ans. (4) Pitcher of Nepenthes [NCERT class 11, page 68,69,71]
122. Which one of the following cell organelles is enclosed by a single membrane ?
Ans. (2) Lysosomes [NCERT class 11, page 134,136,140]
123. Analogous structures are a result of:
- Convergent evolution
- Shared ancestry
- Stabilizing selection
- Divergent evolution
Ans. (1) Convergent evolution [NCERT class 12, page 131]
124. Which one of the following statements is wrong ?
- Cellulose is a polysaccharide.
- Uracil is a pyrimidine.
- Glycine is a sulphur containing amino acid.
- Sucrose is a disaccharide.
Ans. (3) Glycine is a sulphur containing amino acid. [NCERT class 11, page 197]
125. Proximal end of the filament of stamen is attached to the:
- Thalamus or petal
Ans. (3) Thalamus or petal
- Which of the following is not required for any of the techniques of DNA fingerprinting available at present?
- Zinc finger analysis
- Restriction enzymes
- DNA-DNA hybridization
- Polymerase chain reaction
Ans. (1) Zinc finger analysis [NCERT class 12, page 121-122]
- Which one of the following characteristics is not shared by birds and mammals?
- Breathing using lungs
- Warm blooded nature
- Ossified endoskeleton
Ans. (2) Viviparity [NCERT class 11, page 59-60]
- Select the incorrect statement:
- LH triggers ovulation in ovary.
- LH and FSH decrease gradually during the follicular phase.
- LH triggers secretion of androgens from the Leydig cells.
- FSH stimulates theSertoli cells which help in spermiogenesis.
Ans. (2) LH and FSH decrease gradually during the follicular phase.
[NCERT class 11, page 332]
- The amino acid Tryptophan is the precursor for the synthesis of:
- Thyroxine and Triiodothyronine
- Estrogen and Progesterone
- Cortisol and Cortisone
- Melatonin and Serotonin
Ans. (4) Melatonin and Serotonin
- Joint Forest Management Concept was introduced in India during:
Ans. (2) 1980s [NCERT class 12, page 258]
- One of the major components of cell wall of most fungi is:
Ans. (4) chitin [NCERT class 11, page 22]
- A complex of ribosomes attached to a single strand of RNA is known as:
- Okazaki fragment
Ans. (4) polysome [NCERT class 11, page 129]
- Which of the following features is not present in the Phylum – Arthropoda?
- Metameric segmentation
- Jointed appendages
- Chitinous exoskeleton
Ans. (2) Parapodia [NCERT class 11, page 52-53]
- Asthma may be attributed to:
- allergic reaction of the mast cells in the lungs
- inflammation of the trachea
- accumulation of fluid in the lungs
- bacterial infection of the lungs
Ans. (1) allergic reaction of the mast cells in the lungs [NCERT class 12, page 153]
- Pick out the correct statements:
(a) Haemophilia is a sex-linked recessive disease.
(b) Down’s syndrome is due to aneuploidy.
(c) Phenylketonuria is an autosomal recessive gene disorder.
(d) Sickle cell anaemia is an X – linked recessive gene disorder.
- (b) and (d) are correct.
- (a), (c) and (d) are correct.
- (a), (b) and (c) are correct.
- (a) and (d) are correct.
Ans. (3) (a), (b) and (c) are correct. [NCERT class 12, page 89-90]
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