Explore topic-wise MCQs in Cell Biology.

This section includes 92 Mcqs, each offering curated multiple-choice questions to sharpen your Cell Biology knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of following charge is present in phosphate end of DNA?

A. negative
B. positive
C. neutral
D. no charge
Answer» B. positive
2.

Which of following enzymes unwinds and separates DNA strands during replication?

A. helicase
B. proteases
C. topoisomerase
D. telomerase
Answer» B. proteases
3.

How many DNA repair enzymes have been found so far in E Coli?

A. 1000
B. 130
C. 32
D. 12
Answer» C. 32
4.

Which of following is not a part of three models that were proposed for DNA replication?

A. semi conservative
B. destructive
C. conservative
D. dispersive
Answer» C. conservative
5.

Which of following forms chromatin takes when cell enters metaphase stage?

A. diffused mass
B. looped domains
C. coiled
D. supercoiled
Answer» D. supercoiled
6.

Less compacted and more disperse form of DNA is called

A. Euchromatin
B. heterochromatin
C. clumped chromatin
D. diffused chromatin
Answer» B. heterochromatin
7.

Amount of which of following bases is equal to amount Cytosine?

A. thymine
B. guanine
C. adenine
D. uracil
Answer» C. adenine
8.

In which of following secondary structures DNA molecule is folded?

A. alpha helix
B. beta sheets
C. random coil
D. hairpin loops
Answer» B. beta sheets
9.

Patients with Xeroderma pigmentosum are sensitive to which of following?

A. peanuts
B. water
C. sunlight
D. grass
Answer» D. grass
10.

How many primers, leading strand requires to elongate new strand?

A. 1
B. 2
C. 3
D. 4
Answer» B. 2
11.

Which of following enzymes synthesizes RNA primers?

A. protease
B. topoisomerase
C. primase
D. RNAse
Answer» D. RNAse
12.

Which of following proposed double helix structure of DNA?

A. Mendel
B. Marie curie
C. Watson and crick
D. Carl Correns
Answer» D. Carl Correns
13.

Which of following histones is not found in chromatin?

A. h1
B. h2a
C. h2b
D. h3
Answer» B. h2a
14.

How many layers of base pairs is present in every turn of helix?

A. 2
B. 4
C. 5
D. 10
Answer» E.
15.

How many nucleotide pairs are present in DNA of a single human cell?

A. 6 billion
B. 6 million
C. 60 million
D. 2 billion
Answer» B. 6 million
16.

Which of following bases binds with adenine?

A. thymine
B. cytosine
C. guanine
D. uracil
Answer» B. cytosine
17.

In which of following is telomerase most active and hence telomeres are at maximum?

A. somatic cells
B. germ cells
C. heart cells
D. none of above
Answer» C. heart cells
18.

During interphase structure of chromatin is

A. coiled
B. diffused mass
C. supercoiled
D. looped
Answer» C. supercoiled
19.

If unwound, one DNA molecule would be how long?

A. 1 m
B. 10 cm
C. 5 cm
D. 4 cm
Answer» E.
20.

Telomeres are present at which position along chromosome?

A. middle
B. ends
C. near the middle
D. randomly placed
Answer» C. near the middle
21.

What ratio of histones is positively charged?

A. 1/5th
B. 1/6th
C. 1/10th
D. 1/100th
Answer» B. 1/6th
22.

Which of following is basic unit of DNA packaging?

A. chromatin
B. alpha helix
C. nucleus
D. nucleosome
Answer» E.
23.

Histones are made up of approximately how many amino acids?

A. 200
B. 100
C. 500
D. 10
Answer» C. 500
24.

Which of following is a DNA repair system?

A. DNA joining
B. nucleotide excision repair
C. Repairase
D. DNA binding
Answer» C. Repairase
25.

Telomeres typically contain which of following?

A. short repeats
B. genes
C. poly a tail
D. poly t tail
Answer» B. genes
26.

Purine bases have how many rings in their structure?

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
27.

Why was purine-purine bonding theory not consistent with X-Ray diffraction data?

A. it was too wide
B. it was too narrow
C. purines cannot bond together
D. it would tilt sideways
Answer» B. it was too narrow
28.

What is string of DNA between two nucleosomes called?

A. attachment DNA
B. linker DNA
C. pure DNA
D. connecting DNA
Answer» C. pure DNA
29.

Which of following removes RNA nucleotides of primer from 5 prime ends and replaces them with DNA nucleotides?

A. topoisomerase
B. helicase
C. single strand binding proteins
D. DNA polymerase I
Answer» E.
30.

How many DNA molecules are present in nucleus of a single human cell?

A. 23
B. 45
C. 46
D. 12
Answer» D. 12
31.

Virus that infects bacteria are called

A. Bacteriovirus
B. bacteriophage
C. viral phage
D. nano viruses
Answer» C. viral phage
32.

Which of following structures of 30 nm fiber is present in 300 nm fiber?

A. sheets
B. looped domains
C. helix
D. hairpin loops
Answer» C. helix
33.

Which of following is not a part of a DNA molecule

A. pentose sugar
B. nitrogenous base
C. ribose sugar
D. phosphate group
Answer» D. phosphate group
34.

For their experiments, Hershey and Chase tagged phage DNA with which of following radioactive isotopes?

A. sulphur
B. sodium
C. phosphorus
D. radium
Answer» D. radium
35.

Which of following bases binds with cytosine?

A. uracil
B. guanine
C. thymine
D. adenine
Answer» C. thymine
36.

In which of following directions, two backbones of DNA molecule runs?

A. parallel
B. anti parallel
C. intersecting
D. rounded
Answer» C. intersecting
37.

What is rate of elongation of DNA in bacteria?

A. 100 per second
B. 500 per second
C. 20 per second
D. 1 per second
Answer» C. 20 per second
38.

In E Coli, replication of chromosomes starts at a particular site called

A. start of replication
B. initiation of replication
C. start point
D. origin of replication
Answer» E.
39.

In making if 30nm fiber of DNA, which of following histones are involved?

A. h1
B. h2a
C. h2b
D. h3
Answer» B. h2a
40.

Amount of which of following bases is equal to amount Thymine?

A. adenine
B. uracil
C. guanine
D. cytosine
Answer» B. uracil
41.

What is process of tagging each chromosome with molecular tags so each chromosome has a different color, called?

A. coloring
B. painting
C. tagging
D. marking
Answer» C. tagging
42.

How many phosphate groups are lost from DNA as each monomer joins?

A. 2
B. 4
C. 6
D. 8
Answer» B. 4
43.

Segments of DNA synthesized along lagging strand are called

A. replication fragment
B. okazaki fragments
C. lagging fragments
D. leading fragments
Answer» C. lagging fragments
44.

Telomeres from cells that have formed tumors have which of following quality?

A. unusually short
B. unusually long
C. same length
D. absent
Answer» B. unusually long
45.

Which of following bases can make dimers if they're adjacent to a DNA molecule?

A. thymine
B. adenine
C. cytosine
D. uracil
Answer» B. adenine
46.

In which of following direction a new DNA molecule is elongated by polymerase?

A. 5 to 3 end
B. 3 to 5 end
C. no direction
D. along the template strand
Answer» B. 3 to 5 end
47.

From which of following a new DNA template starts?

A. 3 prime end of primer
B. 5 prime end of DNA
C. 5 prime end of primer
D. 3 prime end of DNA
Answer» B. 5 prime end of DNA
48.

Which of following is infected by T2 phage?

A. e coli
B. immune system
C. thermophile bacteria
D. nervous system
Answer» B. immune system
49.

What is diameter of a nucleosome?

A. 5 nm
B. 3 nm
C. 2 nm
D. 10 nm
Answer» E.
50.

How many types of histones are most commonly found in chromatin?

A. 2
B. 3
C. 4
D. 5
Answer» D. 5