Explore topic-wise MCQs in Molecular Biology.

This section includes 64 Mcqs, each offering curated multiple-choice questions to sharpen your Molecular Biology knowledge and support exam preparation. Choose a topic below to get started.

1.

The most popular indirect method of counting virus particles is by

A. hemagglutination assay
B. plaque-assay
C. counting plaque-forming units
D. colony counting
Answer» B. plaque-assay
2.

What kind of embryo is often used for viral assays?

A. Mouse
B. Rat
C. Cat
D. Chicken
Answer» E.
3.

The size of viruses is usually measured in

A. centimeters
B. micrometers
C. nanometers
D. millimeters
Answer» D. millimeters
4.

In order for a virus to replicate

A. the capsid must enter the host cell cytoplasm
B. the host cell must be undergoing mitosis
C. the genome must be released in the cytoplasm
D. the host cell must lack a cell membrane
Answer» D. the host cell must lack a cell membrane
5.

The envelope of an enveloped virus is derived from

A. the mitochondrion of the cell
B. the cell membrane
C. the endoplasmic reticulum of the cell
D. none of these
Answer» C. the endoplasmic reticulum of the cell
6.

Which one is not useful in the treatment of viruses except

A. acyclovir
B. interferon
C. penicillin
D. antibodies
Answer» D. antibodies
7.

Which of the following oncogenic viruses was first detected?

A. Rous sarcoma virus.
B. Epstein-Barr virus
C. Herpes simplex virus type 2
D. Human T cell leukaemia virus
Answer» B. Epstein-Barr virus
8.

Viruses can be purified based on their size and density by using

A. gradient centrifugation
B. differential centrifugation
C. precipitation
D. none of these
Answer» B. differential centrifugation
9.

Which of the following are obligate intracellular parasites?

A. Chlamydia
B. Viruses
C. Rickettsia
D. All of these
Answer» E.
10.

Inclusion bodies of measles virus are

A. intracytoplasmic
B. intranuclear
C. both (a) and (b)
D. none of these
Answer» D. none of these
11.

Which of the following viruses can rescue adenovirus in simian cells?

A. Rabies
B. Vaccinia
C. Simian virus 40
D. Cytomegalovirus
Answer» D. Cytomegalovirus
12.

Which of the following is continuous cell line?

A. HeLa
B. HEp-2
C. KB
D. All of these
Answer» E.
13.

Which of the following virus is susceptible to chloroform?

A. Herpes
B. Influenza
C. Measles
D. All of these
Answer» E.
14.

Enzyme neuraminidase is carried by which of the following viruses?

A. Human immunodeficiency virus
B. Epstein-Barr virus
C. Influenza virus
D. Adenovirus
Answer» D. Adenovirus
15.

Which of the following viruses are relatively thermostable?

A. Human immunodeficiency virus
B. Rubella virus
C. Hepatits A virus
D. Influenza virus
Answer» D. Influenza virus
16.

Which of the following viruses belong/s to family caliciviridae?

A. Hepatitis B virus
B. Hepatitis D virus
C. Hepatitis E virus
D. All of these
Answer» D. All of these
17.

Which of the following viruses belong to family Hepadnaviridae?

A. Hepatitis A virus
B. Hepatitis B virus
C. Hepatitis D virus
D. All of these
Answer» C. Hepatitis D virus
18.

Which of the following viruses belong to family Flaviviridae?

A. Rubella virus
B. Yellow fever virus
C. Hepatitis C virus
D. All of these
Answer» E.
19.

Lesions on chorioallantoic membrane are produced by

A. Herpes B virus
B. Vaccinia virus
C. Herpes simplex virus
D. all of these
Answer» E.
20.

The most efficient way to enclose a space is within a/an

A. sphere
B. cube
C. icosahedron
D. helix
Answer» D. helix
21.

Which of the following virus is enveloped?

A. Adeno
B. Herpes
C. Polio
D. None of these
Answer» C. Polio
22.

The function of a viral capsid is

A. protection against the viral genome from physical and enzymatic destruction
B. providing binding sites that enable the virus to attach to specific receptor sites on the host cell
C. serving as a vehicle of transmission from one host to another
D. all of the above
Answer» E.
23.

Which of the following is not true of virions?

A. Reproduce independently
B. Contain DNA
C. Contain RNA
D. Are extracellular
Answer» B. Contain DNA
24.

The temperate phage that have no site specificity for insertion and may even be able to insert multiple copies of their DNA into a single bacterial chromosome is

A. λ phage enzyme
B. λ DNA
C. Phage Mu
D. Phage Mn
Answer» D. Phage Mn
25.

The repressor protein, since the cell is resistant to lysis from externally infecting phage, is also called

A. immunity repressor
B. immunity operon
C. operon repressor
D. none of these
Answer» B. immunity operon
26.

The temperate phage possesses a gene that codes for a repressor protein which makes the cell resistant to lysis initiated by

A. the prophage
B. lytic infection by other viruses
C. Both (a) and (b)
D. none of these
Answer» D. none of these
27.

The time from infection until lysis is called as

A. eclipse period
B. rise period
C. latent period
D. burst size
Answer» D. burst size
28.

During the first 10 minutes after injection of phage DNA, no phage can be recovered by disrupting the infected bacterium. This is termed as

A. eclipse period
B. rise period
C. latent period
D. burst size
Answer» B. rise period
29.

Lysozyme (an endolysin) which will lyse the bacterial cell, releasing the mature virions is present in

A. immediate early phage genes
B. late genes
C. delayed early genes
D. all of these
Answer» C. delayed early genes
30.

The phage components begin to assemble into mature phages only after the synthesis of

A. structural protein
B. nucleic acid
C. Both (a) and (b)
D. amino acids
Answer» D. amino acids
31.

The viral DNA is removed from the host's chromosomes and the lytic cycle occurs. The process is called

A. spontaneous induction
B. inductive infection
C. resultant induction
D. spontaneous infection
Answer» B. inductive infection
32.

The viral DNA of the temperate phage, instead of taking over the functions of the cell's genes, is incorporated into the host DNA and becomes a prophage in the bacterial chromosome, acting as a gene. This happens in

A. lysogeny
B. spontaneous induction
C. lytic phase
D. none of these
Answer» B. spontaneous induction
33.

The infected cells continue to reproduce themselves as well as the virus, and the mature virions are extruded from the cell surface continuously over a long period of time. This type of release mechanism is called a

A. productive infection
B. inductive infection
C. resultant infection
D. all of these
Answer» B. inductive infection
34.

The yield of phage per bacterium is called the

A. eclipse size
B. latent size
C. burst size
D. none of these
Answer» D. none of these
35.

The extracellular phage number increases until a constant titer at the end of the multiplication cycle. This time interval is termed as

A. eclipse period
B. rise period
C. latent period
D. burst size
Answer» C. latent period
36.

Which of the following bacteriophage is said to have banal symmetry?

A. T2
B. T4
C. T6
D. all of these
Answer» E.
37.

Group E phages have

A. single stranded DNA
B. double stranded DNA
C. single stranded RNA
D. double stranded DNA
Answer» D. double stranded DNA
38.

Which of the following is an example of rod-shaped viruses having their capsomeres arranged helically and not in the stacked ring?

A. Bateriophage M13
B. Bateriophage MV-L2
C. Bateriophage T2
D. Bateriophage T4
Answer» B. Bateriophage MV-L2
39.

In the simplest capsid, there is a capsomere at each of the 12 vertices; this capsomere, which is surrounded by five other capsomeres, is termed a

A. penton
B. polyhedra
C. icosahedral
D. helical
Answer» B. polyhedra
40.

Bacteriophages have been used widely in genetic research, since they are the smallest and simplest biological entities capable of

A. self-replication
B. duplication
C. self-duplication
D. multiplication
Answer» B. duplication
41.

The most complex type of bacterial viruses having hexagonal head, a rigid tail with a contractile sheath and tall fibers is morphologically classified as

A. A
B. B
C. C
D. D
Answer» B. B
42.

The bacterial viruses having head made up of large capsomeres, but no tail is morphologically classified as

A. A
B. B
C. C
D. D
Answer» E.
43.

Virus reproduces in living cells by

A. replication
B. duplication
C. multiplication
D. all of these
Answer» B. duplication
44.

The sequence of nucleic acid in a variety of viruses and viral host, will find more similarities

A. among different viruses than between viruses and their hosts
B. among different viral hosts than among different viruses
C. among different viral hosts than between viruses and their hosts
D. between viruses and their hosts than among different viruses
Answer» E.
45.

Which of the following statements is not true of viruses?

A. Viruses have been successfully grown in pure cultures in test tubes
B. All viruses are obligatory intracellular parasites
C. All viruses have either DNA or RNA as their genetic material
D. Viruses probably arose from small fragments of cellular chromosomes
Answer» B. All viruses are obligatory intracellular parasites
46.

The development of hepatocellular carcinoma is associated with

A. ground squirrel hepatitis virus
B. hepatitis B virus
C. woodchuck hepatitis virus
D. all of the above
Answer» E.
47.

Which of the following viruses can be transmitted by the parenteral route?

A. HBV
B. HCV
C. HDV
D. All of these
Answer» E.
48.

Which of the following is not correct for hepatitis A virus?

A. It can be grown in cell cultures of primate and human cells
B. It is one of the most stable viruses infecting humans
C. It may cause hepatocellular carcinoma
D. None of the above
Answer» D. None of the above
49.

Which of the following antigenic types of hepatitis B virus is present in the envelope?

A. HbsAg
B. HBcAg
C. HBeAg
D. HBxAg
Answer» B. HBcAg
50.

The diagnosis of hepatitis A virus infection is carried out from the method based on

A. aminotransferase levels
B. detection of faecal HAV by immunoelectron microscopy
C. both (a) and (b)
D. detection of IgM anti-HAV by ELISA
Answer» E.