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Genetics and Evolutionary Biology(12)Cell Biology(11)Molecular Biology(23)

Genetics and Evolutionary Biology

12 Questions

GATE→2026→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q1

MCQ[2 Marks]

Match the genetic disorders in Column I to the corresponding underlying cause in Column II **Column I** P. Klinefelter Syndrome Q. Turner syndrome R. Bloom syndrome S. Xeroderma pigmentosum **Column II** 1. X-chromosome insufficiency 2. DNA helicase mutations 3. Nucleotide excision repair defects 4. Extra X chromosome(s) in a male

(A)

P-1; Q-3; R-4; S-2

(B)

P-4; Q-1; R-2; S-3

(C)

P-4; Q-2; R-3; S-1

(D)

P-3; Q-2; R-4; S-1

Explanation

GATE→2026→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q2

NAT[2 Marks]

A disease-associated allele shows X-linked recessive inheritance. If the mother is a carrier of the disease, the father is genetically normal and the child born is a son, then the probability that he is born with the disease is (rounded off to one decimal place)

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q3

NAT[1 Mark]

The allele associated with albinism in humans is recessive (c). The probability that an albino male (cc) and a carrier female (Cc) will have an offspring with normal skin pigmentation is (Round off to one decimal place)

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q4

MSQ[2 Marks]

The blood group of the mother is $A^{+}$ and that of the father is $AB^{+}$. Which of the following statements is/are correct?

(A)

Probability of the offspring with $A^{+}$ blood group is 0.5

(B)

Probability of the offspring with $AB^{+}$ blood group is 0.125

(C)

Probability of the offspring with $B^{+}$ blood group is 0.125

(D)

Probability of the offspring with $O^{+}$ blood group is 0.375

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q5

MCQ[1 Mark]

Mendel's 'law of segregation' is observed in ____ during gamete formation.

(A)

mitochondrial genes

(B)

alleles of a gene

(C)

linked genes

(D)

endoplasmic reticulum

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q6

MCQ[2 Marks]

Match the genetic disorder (Column I) with its molecular basis (Column II). **Column I** P. Sickle-cell anemia Q. Xeroderma pigmentosum R. Tay-Sachs disease S. Down Syndrome **Column II** 1. Mutation in nucleotide excision repair 2. Trisomy of chromosome 21 3. Mutation in $\beta$-globin gene 4. Mutation in hexosaminidase A gene

(A)

P-1; Q-4; R-2; S-3

(B)

P-3; Q-4; R-1; S-2

(C)

P-3; Q-1; R-4; S-2

(D)

P-4; Q-2; R-3; S-1

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q7

MCQ[2 Marks]

____ is an example of neutral evolution.

(A)

Genetic drift

(B)

Directional selection

(C)

Disruptive selection

(D)

Parallel evolution

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q8

MCQ[1 Mark]

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]. Assertion [a]: Chromosome mutations can change the structure of chromosomes. Reason [r]: All chromosome mutations arise due to nondisjunction of chromosomes during mitosis or meiosis.

(A)

Both [a] and [r] are false

(B)

[a] is true but [r] is false

(C)

Both [a] and [r] are true and [r] is the correct reason for [a]

(D)

Both [a] and [r] are true but [r] is not the correct reason for [a]

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q9

MCQ[1 Mark]

C-value paradox refers to

(A)

the lack of correlation between genome size and genetic complexity of an organism

(B)

the presence of genetic sequences that propagate themselves within a genome

(C)

the coexistence of multiple alleles at a genetic locus

(D)

the concept that two or more genes may have the same function

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q10

NAT[1 Mark]

Fabry disease in humans is a X-linked disease. The probability (in percentage) for a phenotypically normal father and a carrier mother to have a son with Fabry disease is

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q11

NAT[1 Mark]

Assuming independent assortment and no recombination, the number of different combinations of maternal and paternal chromosomes in gametes of an organism with a diploid number of 12 is

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Genetics and Evolutionary Biology

Q12

MCQ[2 Marks]

Which of the following conditions will contribute to the stability of a gene pool in a natural population? P. Large population Q. No net mutation R. Non-random mating S. No selection

(A)

P only

(B)

P and Q only

(C)

P and R only

(D)

P, Q and S only

Explanation

Cell Biology

11 Questions

GATE→2026→Genetics, Cellular and Molecular Biology→Cell Biology

Q13

MSQ[1 Mark]

Which of the following is/are extra-cellular matrix protein(s)?

(A)

Myosin

(B)

Fibronectin

(C)

Lamin

(D)

Collagen

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Cell Biology

Q14

MSQ[2 Marks]

Which of the following proteins is/are involved in intraflagellar transport?

(A)

Microtubules

(B)

Myosin

(C)

Actin

(D)

Kinesin / Dynein motors (Option D)

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Cell Biology

Q15

MCQ[1 Mark]

Post-translational modification of proteins is observed in

(A)

Golgi complex

(B)

mitochondria

(C)

peroxisomes

(D)

cytoplasm

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Cell Biology

Q16

MCQ[1 Mark]

During normal embryonic development of the mice paw, elimination of cells from the inter-digital space is due to

(A)

apoptosis

(B)

meiosis

(C)

mutagenesis

(D)

necrosis

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Cell Biology

Q17

MSQ[2 Marks]

Under which of the following conditions, a mammalian somatic cell fails to undergo mitosis during cell cycle?

(A)

Initiation of cell plate formation

(B)

Incomplete DNA replication

(C)

Chiasmata formation

(D)

Irreparable DNA damage

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Cell Biology

Q18

MCQ[1 Mark]

Acetylcholine released by the parasympathetic nerves has which one of the following functions in the heart pacemaker cells?

(A)

It binds to GPCR and activates G protein to slow the heart rate

(B)

It stimulates GABA-activated ion-channel coupled receptor to increase the heart rate

(C)

It binds to GPCR and inhibits G protein to slow the heart rate

(D)

It inhibits GABA-activated ion-channel coupled receptor to increase the heart rate

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Cell Biology

Q19

MCQ[1 Mark]

Intracellular proteins are targeted for proteolytic degradation in proteasomes upon conjugation with

(A)

ubiquitin

(B)

integrin

(C)

peptidase

(D)

calreticulin

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Cell Biology

Q20

MSQ[2 Marks]

The event(s) that lead(s) to inactivation of tumor suppressor genes in cancer cells is(are)

(A)

gene amplification

(B)

promoter methylation

(C)

loss of heterozygosity

(D)

histone acetylation

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Cell Biology

Q21

MCQ[1 Mark]

Match the component of eukaryotic cells (Column I) with its respective function (Column II). **Column I** P. Lysosome Q. Peroxisome R. Glyoxysome S. Cytoskeleton **Column II** 1. Digestion of macromolecules 2. Detoxification of harmful compounds 3. Conversion of fatty acids to sugar 4. Involvement in cell motility

(A)

P-1, Q-2, R-3, S-4

(B)

P-2, Q-1, R-3, S-4

(C)

P-3, Q-1, R-2, S-4

(D)

P-4, Q-3, R-1, S-2

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Cell Biology

Q22

MCQ[2 Marks]

The enzymes involved in ubiquitinylation of cell-cycle proteins are

(A)

$E_{1}$ and $E_{2}$ only

(B)

$E_{1}$ and $E_{3}$ only

(C)

$E_{1}$ and $E_{4}$ only

(D)

$E_{1}$, $E_{2}$ and $E_{3}$

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Cell Biology

Q23

MSQ[2 Marks]

Which of the following statement(s) regarding trafficking in eukaryotic cells is(are) CORRECT?

(A)

Dynamin binds GTP and is involved in vesicle budding

(B)

Dynamin is involved in cytoskeletal remodelling

(C)

Dynein binds ATP and is involved in movement of organelles along microtubules

(D)

Dynein binds GTP and is involved in movement of organelles along microtubules

Explanation

Molecular Biology

23 Questions

GATE→2026→Genetics, Cellular and Molecular Biology→Molecular Biology

Q24

MCQ[1 Mark]

The RNA primer synthesized during bacterial DNA replication is removed by

(A)

DNA gyrase

(B)

DNA Polymerase I

(C)

Primase

(D)

DNA Polymerase III

Explanation

GATE→2026→Genetics, Cellular and Molecular Biology→Molecular Biology

Q25

MSQ[2 Marks]

Messenger RNAs (mRNAs) translate to generate polypeptides and the translation terminates at the UGA, UAG or UAA stop codons. The AGA codon acts as additional stop codon in the mitochondria. The longest possible polypeptide(s) that can be hypothetically translated in the cytosol and/or mitochondria, from the given full length mRNA sequence (36 nucleotides) is/are 5'-AACACCAUGACCCAUGUGGCGAGACGGUAGUUAAAA-3'

(A)

7 amino acids long in the cytosol

(B)

5 amino acids long in the mitochondria

(C)

6 amino acids long in the mitochondria

(D)

8 amino acids long in the cytosol

Explanation

GATE→2026→Genetics, Cellular and Molecular Biology→Molecular Biology

Q26

MSQ[2 Marks]

The RNA sequence below depicts the part of a 330 nucleotides long mRNA and it encodes the C-terminal portion of a protein. 5'-......... AAC ACC ACG ACC CAU GUG GCG AGA CGG UAG-3' A mutation was identified in this RNA denoted as 322AU. This nucleotide change is represented by which of the following class(es) of mutation?

(A)

Missense mutation

(B)

Non-sense mutation

(C)

Transversion mutation

(D)

Silent mutation

Explanation

GATE→2026→Genetics, Cellular and Molecular Biology→Molecular Biology

Q27

MSQ[2 Marks]

Which of the following is/are posttranslational modification(s) involved in epigenetic control of gene expression?

(A)

Arginine methylation

(B)

Lysine acetylation

(C)

Cytosine methylation

(D)

Cytosine deamination

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Molecular Biology

Q28

MCQ[1 Mark]

Which one of the following is true for piRNAs?

(A)

piRNAs silence transposable elements in germ cells

(B)

piRNA is the abbreviation of P-element interacting RNA

(C)

piRNAs modify the 2'-OH of ribose with methyl group

(D)

piRNA is a long non-coding RNA

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Molecular Biology

Q29

MSQ[1 Mark]

Which of the following enzymes is/are involved in the biogenesis of miRNA?

(A)

Drosha

(B)

Cas9

(C)

XRCC4

(D)

Dicer

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Molecular Biology

Q30

NAT[1 Mark]

The contour length of a B-DNA molecule that encodes a bacterial protein of 33 kDa is nm. Consider the average molecular weight of an amino acid as 110 Da and helix rise per base pair for B-DNA as 0.34 nm. (Round off to the nearest integer)

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Molecular Biology

Q31

MCQ[2 Marks]

Correctly match the Enzyme with its respective Function. **Enzyme** P. Gyrase Q. Deadenylase R. Glycosylase S. DNA ligase **Function** 1. Removes a damaged base by cleaving the bond between sugar and base 2. Provides a swivel allowing one DNA strand to rotate around the other 3. Catalyses bond formation between 3'-OH and 5'-phosphate end of nucleotides in duplex DNA 4. Is an exoribonuclease that removes the poly(A) tail

(A)

P-2; Q-4; R-1; S-3

(B)

P-1; Q-4; R-2; S-3

(C)

P-2; Q-1; R-4; S-3

(D)

P-3; Q-2; R-1; S-4

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Molecular Biology

Q32

MSQ[2 Marks]

Which of the following statements about initiation of DNA replication in eukaryotes is/are true?

(A)

DNA replication is initiated at the origin of replication licensed by loading of Mcm helicase complex

(B)

Loading of Mcm helicase complex takes place in S phase

(C)

Mcm helicase complex are activated by S-Cdks

(D)

Mcm helicase complex is responsible for loading of origin recognition complex

Explanation

GATE→2025→Genetics, Cellular and Molecular Biology→Molecular Biology

Q33

MSQ[2 Marks]

Which of the following statements is/are true about telomerase?

(A)

Telomerase has 5'-3' DNA-dependent DNA polymerisation activity

(B)

Telomerase has 5'-3' RNA-dependent DNA polymerisation activity

(C)

Telomerase contains an RNA subunit

(D)

Telomerase has 3'-5' DNA-dependent DNA polymerisation activity

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Molecular Biology

Q34

MCQ[1 Mark]

If a denatured protein of human origin is renatured, ____ structure will recognize the original function

(A)

primary

(B)

secondary

(C)

tertiary

(D)

quaternary

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Molecular Biology

Q35

MCQ[2 Marks]

Match the enzyme (Column I) with its corresponding function (Column II). **Column I** P. Primase Q. Reverse transcriptase R. RNA Replicase S. DNA Polymerase III **Column II** 1. RNA dependent RNA synthesis 2. DNA dependent DNA synthesis 3. RNA dependent DNA synthesis 4. DNA dependent RNA synthesis

(A)

P-4; Q-1; R-3; S-2

(B)

P-2; Q-1; R-3; S-4

(C)

P-3; Q-4; R-2; S-1

(D)

P-4; Q-3; R-1; S-2

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Molecular Biology

Q36

MSQ[2 Marks]

Which of the following statements regarding the below mentioned mRNA sequence is/are TRUE? 5'-UGAUGAGCCUUAACCGGGAACGAAUUUAAG-3'

(A)

It contains nine codons in the reading frame

(B)

It contains ten codons in the reading frame

(C)

It codes for eight amino acids

(D)

It codes for nine amino acids

Explanation

GATE→2024→Genetics, Cellular and Molecular Biology→Molecular Biology

Q37

MSQ[2 Marks]

Which of the following conditions induce(s) the expression of $\beta$-galactosidase gene in the lac operon?

(A)

Absence of glucose

(B)

Absence of lactose

(C)

Presence of glucose

(D)

Presence of lactose

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Molecular Biology

Q38

MCQ[1 Mark]

Eukaryotic transcription is carried out by

(A)

DNA-dependent RNA polymerase

(B)

DNA-dependent DNA polymerase

(C)

RNA-dependent DNA polymerase

(D)

RNA-dependent RNA polymerase

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Molecular Biology

Q39

MCQ[1 Mark]

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]. Assertion [a]: In multicellular organisms, cells of different lineages have different gene expression profiles. Reason [r]: Alternative splicing is the only mechanism to generate protein diversity.

(A)

Both [a] and [r] are false

(B)

Both [a] and [r] are true and [r] is the correct reason for [a]

(C)

Both [a] and [r] are true but [r] is not the correct reason for [a]

(D)

[a] is true but [r] is false

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Molecular Biology

Q40

MCQ[1 Mark]

Match the types of RNA in Group I with their corresponding function in Group II. **Group I** P. mRNA Q. rRNA R. miRNA S. tRNA **Group II** 1. Serves as adaptors between mRNA and amino acids during protein synthesis 2. Regulates post-transcriptional gene expression 3. Codes for proteins 4. Forms the core of the ribosome structure and catalyzes protein synthesis

(A)

P-3, Q-4, R-2, S-1

(B)

P-3, Q-4, R-1, S-2

(C)

P-4, Q-3, R-2, S-1

(D)

P-2, Q-1, R-4, S-3

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Molecular Biology

Q41

MSQ[2 Marks]

Methylation of CpG islands near the promoter of a gene can inhibit transcription by

(A)

preventing RNA polymerase binding

(B)

facilitating repressor binding

(C)

facilitating heterochromatin formation

(D)

inducing euchromatin formation

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Molecular Biology

Q42

NAT[2 Marks]

DNA sample collected from an unidentified bacterial species (Y) contains 13% of adenine. The G+C content (in percentage) of Y is

Explanation

GATE→2023→Genetics, Cellular and Molecular Biology→Molecular Biology

Q43

NAT[2 Marks]

If 1000 bp of a double-helical DNA weighs $1\times10^{-18}$ gm and distance between two bp is 0.34 nm, the total amount of DNA (in mg, rounded off to one decimal place) required to stretch from Earth to Moon (assuming the distance between Earth and Moon to be 3,74,000 km) is

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Molecular Biology

Q44

MCQ[1 Mark]

In animal cells, the endogenously produced miRNAs silence gene expression by

(A)

base pairing with the 3'-untranslated region of specific mRNAs

(B)

blocking mRNA synthesis

(C)

binding to the operator site

(D)

base pairing with the 3' region of specific rRNAs

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Molecular Biology

Q45

MCQ[2 Marks]

Adenine can undergo a spontaneous change to hypoxanthine in a cell, leading to a DNA base pair mismatch. The CORRECT combination of enzymes that are involved in repairing this damage is

(A)

Nuclease, DNA polymerase, DNA ligase

(B)

Nuclease, DNA ligase, helicase

(C)

Primase, DNA polymerase, DNA ligase

(D)

Primase, helicase, DNA polymerase

Explanation

GATE→2022→Genetics, Cellular and Molecular Biology→Molecular Biology

Q46

MSQ[2 Marks]

Which of the following statement(s) is (are) CORRECT regarding the lac operon in E. coli when grown in the presence of glucose and lactose?

(A)

At low glucose level, the operon is activated

(B)

At high glucose level, the operon is activated to enable the utilization of lactose

(C)

The lac repressor binds to operator region inactivating the operon

(D)

Binding of lactose to the lac repressor induces the operon

Explanation