AIIMS Practice Test Paper 1 Zoology by TEACHING CARE online tuition and coaching classes

AIIMS Practice Test Paper 1 Zoology by TEACHING CARE online tuition and coaching classes.

                                      AIIMS Mock Test Paper 1


  1. The plasma membrane of a cell is composed of

A protein molecules arranged in two layers with polar areas on outside of the membrane.

B two layers of lipids arranged with the nonpolar tails forming the interior of the membrane.

C lipid molecules arranged between two carbohydrate layers.

D protein molecules with polar and nonpolar tails.


  1. The most important information to the development of genetic engineering techniques is ?

A the observation of dominant alleles

B the discovery of non lethal genes

C the formulation of Punnett squares

D the structure of a DNA molecule


  1. The cell membrane of RBCs allows water, oxygen, carbon dioxide, and glucose to cross through while other substances are not allowed to pass through, Such a membrane is called as

A Semi-perforated.

B semi-permeable.

C non-conductive.

D permeable.


  1. Which of the following is the most likely order of succession in an area after a volcanic eruption?

A lichens grasses shrubs trees

B mosses →grasses →lichens →trees

C grasses →trees →mosses →lichens

D shrubs →grasses →trees →lichens


5 What causes tomatoes to ripen much more slowly in a refrigerator than if they are placed at room temperature?

A Tomatoes require sunlight to ripen.

B Humidity fastens the ripening process.

C Low temperature reduces the action of ripening enzymes.

D Enzymes produced by bacteria inhibit ripening.


6  The cytoplasm of a  cell has many different enzymes. How does a specific enzyme catalyzes a specific reaction?

A Different enzymes are synthesized in specific areas of the cytoplasm.

B Most enzymes can catalyze many different reactions.

C An enzyme binds to a specific substrate (reactant) for the reaction catalyzed.

D Enzymes are transported to specific substrates (reactants) by ribosomes.


7 Some snake venoms  destroy blood cells or tissues. The damage caused by such a snake bite could best be slowed down by

A applying ice to the bite area.

B drinking large amounts of water.

C inducing vomiting.

D increasing blood flow to the area.


8 The enzyme maltase breaks down maltose  into glucose molecules . Which of the following would slow the rate of the reaction ?

A adding maltase

B adding maltose

C removing glucose

D diluting with water


9 Eukaryotic cells are different from prokaryotic cells because eukaryotic cells

A are much smaller.

B have non-permeable membranes.

C have a higher rate of reproduction.

D have nuclei.


10 The cellular organelle responsible for packaging the proteins that the cell secretes is ?

A cytoskeleton

B cell membrane

C lysosome

D Golgi apparatus


11 The molecule in plant cells that first captures the radiant energy from sunlight?

A glucose

B carbon dioxide

C chlorophyll

D adenosine triphosphate

  1. Carbohydrates are composed of
  2. amino acids.
  3. nucleic acids.
  4. monosaccharides.
  5. glycerol and fatty acids.


  1. The unit molecule of a protein is
  2. glucose.
  3. glycerol.
  4. a fatty acid.
  5. an amino acid.


  1. Glucose in cells is used primarily
  2. as an energy source.
  3. to produce membranes.
  4. to store genetic material.
  5. to produce enzymes that catalyze reactions.



15 The first stage of photosynthesis in the chloroplast is

A light-dependent.

B temperature-dependent.

C glucose-driven.

D ATP-driven.


16 A heart muscle cell would  have an unusually high proportion of

A lysosomes.

B mitochondria.


D Golgi bodies.


17 The Krebs cycle in aerobic respiration, takes place in

A chloroplasts.

B nuclei.

C lysosomes.

D mitochondria.


18 Which of the following statements correctly

describes meiosis?

A Cells divide only once during meiosis.

B Meiosis does not take place in reproductive cells.

C The daughter cells produced at the end of meiosis are genetically identical to the parent cell.

D The cells produced at the end of meiosis contain half the number of chromosomes as the parent cell.


19 Which of the following best describes meiosis?

A It takes place in all tissues that require cell replacement.

B It taks place only in cells in the reproductive structures of the organism.

C It occurs in all tissues except the brain and spinal cord.

D It is the first stage of mitosis.


20 What are the possible genetic combinations that could be present in a single grain of pollen from a corn plant having a genotype of Ttyy?

A Ty, ty

B TY, ty

C TY, Ty, ty

D Ty, ty, tY, TY


21 Given below are the typical diploid number of chromosomes of several different organisms.









Fruit fly


Which of the following is the best explanation for the even number of chromosomes in each of these organisms?

  1. It is only a coincidence; many other organisms have an odd number of chromosomes.
  2. The diploid chromosome number is always even so that when mitosis occurs each new cell gets the same number of chromosomes.
  3. The diploid chromosome number represents pairs of chromosomes, one from each parent, so it is always an even number.
  4. Chromosomes double every time the cell divides, so after the first division, the number is always even.


22 Based only on the sex chromosomes, the probability of producing a female from typical human egg and sperm at fertilization is

A 25%.

B 50%.

C 75%.

D 90%.


  1. Which of the following statements best describes DNA replication?
  2. tRNA, by complementary base pairing with mRNA, produces proteins.
  3. RNA nucleotides, by complementary base pairing with DNA, produce DNA.
  4. DNA nucleotides, by complementary base pairing with DNA,

produce DNA.

  1. RNA nucleotides, by complementary base pairing with DNA, produce tRNA.


  1. The base found in RNA nucleotides but not in DNA nucleotides is
  2. uracil (U).
  3. adenine (A).
  4. guanine (G).
  5. cytosine (C).


  1. The product of transcription is
  2. DNA.
  3. protein.
  4. mRNA.
  5. a ribosome


  1. In fruit flies, the gene for red eyes (R) is dominant and the gene for sepia eyes (r) is recessive. What are the possible combinations of genes in the offspring of two red-eyed heterozygous flies (Rr)?

A RR only

B rr only

C Rr and rr only

D RR, Rr, and rr only


27 If a human male baby  inherits a recessive allele from his mother, in which situation would he most likely show the trait coded for by the recessive allele?

A The baby inherits the dominant allele from his father.

B The allele is on an autosomal chromosome and the baby is a twin.

C The allele is on the X chromosome.

D The allele is on the Y chromosome.


28 The reproductive cells have only one factor for each inherited trait. This hypothesis of Mendel is supported by the observation that

A haploid cells are produced by mitosis.

B diploid cells are produced by mitosis.

C haploid cells are produced by meiosis.

D diploid cells are produced by meiosis.



The above sequence of DNA is part of a gene. How many amino acids are coded for by this sequence?

A 4

B 8

C 12

D 20


30 A scientist puts nucleotide chains of UUUUUU in a test tube under conditions that allow protein synthesis. Soon the test tube is full of polypeptide chains composed of only the amino acid phenylalanine. What does this experiment indicate?

A The amino acid phenylalanine is consists of uracil.

B UUU codes for the amino acid phenylalanine.

C Protein synthesis is impaired in test tubes.

D Most proteins contain only one type of amino acid.


31 Which of these would most probabily cause a mutation?

A the placement of ribosomes on the endoplasmic reticulum

B the insertion of a nucleotide into DNA

C the movement of tRNA out of the nucleus

D the release of mRNA from DNA


32 A human disease is caused by a change in one codon in a gene from GAA to GUA. This disease results because of

A a mutation.

B a meiosis error.

C crossing-over.

D polyploidy.


  1. The area of an enzyme into which a substrate fits is called the
  2. catalyst.
  3. product.
  4. active site.
  5. activated complex.


  1. The molecule that fits into the enzyme’s active site is the
  2. codon.
  3. vitamin.
  4. substrate.
  5. coenzyme.


  1. The active site of an enzyme is
  2. formed by the substrate.
  3. altered by heavy metals.
  4. altered by the substrate concentration.
  5. destroyed during its reaction with a substrate.


  1. High concentrations of thyroxin in the blood will cause metabolic reactions in a cell to
  2. speed up.
  3. slow down.
  4. stop occurring.
  5. remain unchanged.


  1. Why would drugs like penicillin destroy bacteria but have no effect on human cells?
  2. Human enzymes would be denatured by penicillin.
  3. Bacterial cells would use penicillin as a coenzyme.
  4. Penicillin would fit the active site of bacterial enzymes.
  5. Enzymes in human cells would use penicillin to produce excess energy.


  1. Thyroxin treatment can be used to stimulate weight loss in some people with an endocrine deficiency. This treatment will
  2. cause a loss of appetite.
  3. increase the metabolic rate.
  4. prevent the conversion of fatty acids to fat.
  5. accelerate the conversion of glucose to glycogen.


  1. The pituitary gland secretes a hormone into the bloodstream which stimulates the production of thyroxin. In turn, production of thyroxin is inhibited by
  2. the effect of thyroxin on the adrenal gland.
  3. the effect of thyroxin on the pituitary gland.
  4. decreasing the amount of calcium in the diet.
  5. increasing the amount of iodine in the blood


40 Many different kinds of proteins exist even though there are a limited number of amino acids, because the

A size of a given amino acid can vary.

B chemical composition of a given amino acid can vary.

C sequence and number of amino acids is different.

D same amino acid can have many different properties.


41 When cooked, the clear protein of an egg white becomes opaque and firm because the heat

A mutates the DNA.

B turns the protein into carbohydrates.

C stops protein formation.

D changes the protein structure.


42 How would the base sequence ACAGTGC be coded on mRNA?






43 Semi-conservative DNA replication indicates to the idea that

A DNA molecules require unwinding before duplication begins.

B each new DNA molecule contains two new single RNA strands.

C the two strands of DNA molecules run in opposite directions.

D each half of the original DNA molecule is joined with a new complementary DNA strand.


44 The bacterium Agrobacterium tumefaciens infects plants, and a portion of its DNA is inserted into the plant’s chromosomes. This maks the plant to produce gall cells, which manufacture amino acids that the bacterium uses as nutrients. This process is a natural example of

A polyploidy.

B genetic manipulation.

C grafting.

D hybridization.


45 The milk of goats produced by genetic engineering contains proteins that can be used as medicines. This effect was produced by

A mixing foreign genes into the milk.

B injecting foreign genes into the goats’ udders.

C inserting foreign genes into fertilized goat eggs.

D genetically modifying the nutritional needs of the goats’ offspring.


46 It was found that, over a period of 300 years, a mountain pond was converted into a meadow. During that time, several communities of organisms were replaced by different communities. Which of the following best explains why new communities were able to replace older communities?

A The original species became extinct.

B Species in the older community died from old age.

C The abiotic characteristics of the habitat changed.

D Diseases that killed the older organisms disappeared.


47 Which of the following organisms are most helpful in preventing the earth from being covered with the dead bodies of organisms?

A carnivores

B producers

C parasites and viruses

D fungi and bacteria


48 Which of the following organisms would most likely be found at the top of an energy pyramid?

A clams

B sardines

C sharks

D kelp


49 Which of the following organisms would most likely be found at the bottom of a biomass pyramid?

A giant squids

B sand sharks

C sea cucumbers

D green algae

50 Which of the following would have the least effect on natural selection in a subspecies of giraffes that is geographically isolated from other subspecies of giraffes?

A available niches

B existing predators

C chromosome number

D available food resources


51 In carrier pigeons there is a rare inherited condition that causes  death of the chicks before hatching. In order to pass this disease from generation to generation there must be parent birds that

A are heterozygous for the disease.

B have the disease themselves.

C produce new mutations for this disease.

D are closely interbred.


52 A healthy individual who is a carrier of a lethal allele but unaffected by it. What is the probable genotype of such an individual?

A two dominant normal alleles

B one recessive lethal allele and one dominant lethal allele

C one recessive lethal allele and one dominant normal allele

D one dominant lethal allele and one recessive normal allele


53 A genetic disorder due to a recessive allele (a) is lethal in homozygous individuals (aa), whereas heterozygous individuals (Aa) have no symptoms. Based on this observation, which of the following is likely to result?

A The disorder will quickly be eliminated since no recessive homozygotes will survive to reproduce.

B The disorder will be maintained in the population through the reproduction of heterozygotes.

C Only homozygous dominant (AA) individuals will survive.

D The prevalence of the disorder will increase over time.


54 Mutations in a DNA sequence are

A natural processes that produce genetic diversity.

B natural processes that always affect the phenotype.

C unnatural processes that always affect the phenotype.

D unnatural processes that are harmful to genetic diversity.


  1. The minimum distance at which a microscope is capable of distinguishing two points as separate is its
  2. magnification
  3. illumination
  4. resolving power
  5. Separation power


  1. A Gram negative cell wall is as compared to a Gram positive one is
  2. thicker
  3. thinner
  4. More peptidoglycan
  5. Less LPS (lipopolysaccharides)


  1. Because penicillin prevents peptidoglycan synthesis, it is more effective on _______________ cells.
  2. Gram positive
  3. Gram negative

C Both

  1. None
  2. Flagella and pili are made of
  3. lipids
  4. carbohydrates
  5. nucleic acids
  6. protein


  1. The genetic information of bacteria is stored in _______, in one circular chromosome located in the cytoplasm.
  2. DNA
  3. protein
  4. phospholipids
  5. RNA


  1. Differences between eukaryotic and prokaryotic cells include all of the following except
  2. eukaryotic cells have mitochondria
  3. prokaryotic cells have more complex cell walls
  4. eukaryotic cells have cilia and flagella with complex structure
  5. prokaryotic cells have no genetic material





Note: The Correct answer in each question has been made bold.



Hints and explainations:-

  1. Prokaryotes do not have a nucleus
  2. Muscles require energy for contraction that is produced by mitochondria

25 Product of translation is protein

  1. Cofactors can also be classified depending on how tightly they bind to an enzyme, with loosely-bound cofactors termed coenzymes and tightly-bound cofactors termed prosthetic groups

36 Thyroxin increases BMR (Basal metabolic rate)

  1. Heating denatures proteins

44 Genetic manipulation is carried out in genetic engineering

57 Gram + Bacteria have more peptidoglycan in their cell walls

60 prokaryotic cells do have  genetic material in the form of nucleiod





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