Explore topic-wise MCQs in Biology.

This section includes 302 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.

51.

Segment of 'RNA' that have both negative and positive polarity regions is known as

A. Neutral
B. Dipolar
C. Monopolar
D. Ambisense
Answer» E.
52.

The plasmid-mediated properties is/are

A. fermentation of lactose
B. production of enterotoxin
C. resistance to antibiotics
D. all of these
Answer» E.
53.

The PCR/sequencing approach to rRNA is most likely to give information about

A. the species to which the bacteria are most closely related
B. morphology of the bacterium
C. the type of energy metabolism the bacterium has
D. whether the bacterium is motile
Answer» B. morphology of the bacterium
54.

In which of the following uracil is present?

A. RNA
B. DNA
C. Both (a) and (b)
D. None of these
Answer» B. DNA
55.

Changes in which of the following characterizes mutations?

A. Phenotype
B. Genotype
C. Both (a) and (b)
D. None of these
Answer» D. None of these
56.

Which of the following component of RNA polymerase facilitates the recognition of promoter sequences?

A. a subunit
B. b subunit
C. s subunit
D. c subunit
Answer» D. c subunit
57.

A sudden change in sequence of DNA or RNA, is called

A. Change
B. Alteration
C. Mutation
D. Transduction
Answer» D. Transduction
58.

In lysogeny,

A. a bacteriophage transfers bacterial DNA
B. bacteria take up double stranded DNA from the environment
C. DNA-degrading enzymes in the extracellular medium would stop the process
D. a bacteriophage genome is integrated into the bacterial genome
Answer» E.
59.

Which of the following is used by microbial genetisists as a tool?

A. Bacteriophage
B. Plasmids
C. Transposable elements
D. All of these
Answer» E.
60.

Which of the following infection(s) can be diagnosed by the use of polymerase chain reaction?

A. HIV-1 and HIV-2 viruses
B. Hepatitis B virus
C. Mycobacterium tuberculosis
D. All of these
Answer» E.
61.

According to base pairing rules the bases of one strand match-up with the bases of the second strand of DNA and the two strands are said to be

A. complementary
B. oppositely charged
C. identical
D. none of these
Answer» B. oppositely charged
62.

If a base replaces by another base pair, sequence mutation, resulting replacement is known as

A. Alternation
B. Substitution
C. Missense
D. Nonsense
Answer» C. Missense
63.

Process by which virus transfer gene from one cell to another, called as

A. Replication
B. Transfer
C. Translation
D. Transduction
Answer» E.
64.

During 'conjugation' process of mating is controlled by

A. F plasmid
B. Fertility plasmid
C. F factored
D. All of above
Answer» E.
65.

Integration of viral 'DNA' into cell 'DNA' results in a structure named as

A. Viral genome
B. Prophage
C. Virion
D. Prion
Answer» C. Virion
66.

When exchange of segment between viruses having segmented genome, process is known as

A. Recombination
B. Transfer
C. Translation
D. Reassortment
Answer» E.
67.

During amino acid activation a(n)

A. amino acid is bound to tRNA
B. amino acid is bound to mRNA
C. methyl group is attached to rRNA
D. methyl group is attached to an amino acid
Answer» B. amino acid is bound to mRNA
68.

When mutations involve vital functions so that the mutants are nonviable, it is a

A. nonsense mutation
B. lethal mutation
C. transversion
D. none of these
Answer» C. transversion
69.

The whole-genome shotgun sequencing approach depends primarily on

A. rapidly sequencing thousands of small randomly cloned fragments
B. methodical sequencing a few large cloned fragments of DNA
C. sequencing the bacterial chromosome while it is still intact
D. all of the above
Answer» B. methodical sequencing a few large cloned fragments of DNA
70.

RNA that is complementary to a segment of another RNA molecule to which it will bind is known as

A. missense RNA
B. antisense RNA
C. nonsense RNA
D. none of these
Answer» C. nonsense RNA
71.

F factor plasmids play a major role in

A. conjugation
B. replication
C. transduction
D. trasnscription
Answer» B. replication
72.

What is the usual sequence of a Pribnow box?

A. AUAUA
B. TATAAT
C. UUUUU
D. TTGACA
Answer» C. UUUUU
73.

Which of these catalyzes the synthesis of RNA from a DNA template?

A. DNA gyrase
B. DNA ligase
C. DNA polymerase
D. RNA polymerase
Answer» E.
74.

Which of the termination codon is called amber?

A. UAA
B. UAG
C. UGA
D. AUG
Answer» C. UGA
75.

Process, viruses or viral vectors, in combination with foreign viral envelope, producing proteins, known as

A. Genotyping
B. Pseudotyping
C. Phenotyping
D. Exchange
Answer» C. Phenotyping
76.

Recombination of virus genomes occurs

A. by transduction
B. by transription
C. simultaneous infection of a host cell by two viruses with homologous chromosomes
D. by transformation
Answer» D. by transformation
77.

Mutations that are valuable in determining function of viral 'gene' is called

A. Substitution
B. Frameshift mutation
C. Conditional lethal mutation
D. Point mutation
Answer» D. Point mutation
78.

The correct term for the transfer of genetic material between bacteria in direct physical contact is

A. conjugation
B. transformation
C. replication
D. transduction
Answer» B. transformation
79.

Which of the following statement can describe horizontal transfer?

A. The synthesis of protein in RNA
B. The transmission of genetic information from one independent, mature organism to another
C. The transmission of genetic information from parent to offspring
D. The synthesis of RNA from a DNA template
Answer» C. The transmission of genetic information from parent to offspring
80.

What are approximate numbers of base pairs bacterial DNA ?

A. 5 x 10^10
B. 5 x 10^6
C. 5 x 10^8
D. 5 x 10^11
Answer» C. 5 x 10^8
81.

During process of complementation, helping virus mediate replication, in the

A. Prion
B. Virion
C. Viroid
D. Defective virus
Answer» E.
82.

The components found in all prokaryotic transcription terminators is

A. a poly-U region
B. Rho factor
C. a hairpin structure
D. none of these
Answer» D. none of these
83.

A wall less mycoplasma, having molecular weight, approximately

A. 5 x 10^6
B. 5 x 10^10
C. 5 x 10^11
D. 5 x 10^8
Answer» E.
84.

The main difference between a self-transmissible and a mobilizable plasmid is that the self-transmissible plasmid

A. transfers both strands of the plasmid DNA
B. carries genes encoding the mating apparatus
C. transfers antibiotic resistance genes
D. usually has a transposon inserted into it
Answer» C. transfers antibiotic resistance genes
85.

Thymine dimers are directly repaired with the help of visible light by process known as

A. phosphorylation
B. excision repair
C. photosynthesis
D. photoreactivation
Answer» E.
86.

Which of the following genetic elements carry the genes required for integration into host chromosomes?

A. Replicon
B. Plasmids
C. Transposons
D. Tandons
Answer» D. Tandons
87.

Example of single-stranded 'RNA' virus with negative polarity is

A. Myxovirus
B. Parvoviruses
C. Poxvirus
D. Poliovirus
Answer» B. Parvoviruses
88.

The nonsense codon(s) is/are

A. UAG
B. UAA
C. UGA
D. all of these
Answer» E.
89.

Recipient bacteria in conjugation are usually

A. Female bacterium
B. Male bacterium
C. Bacterium
D. E.Coli
Answer» B. Male bacterium
90.

Plasmid that carries genes encoding enzymes, which degrade substances such as aromatic compounds, pesticides or sugar are

A. F factors
B. metabolic plasmid
C. virulence plasmid
D. none of these
Answer» C. virulence plasmid
91.

Which type of plasmid can exist with or without being integrated into the host's chromosome?

A. Medisome
B. Lisosome
C. Lysogen
D. Episome
Answer» E.
92.

First step of 'viral replication' cycle is

A. Attachment
B. Penetration
C. Uncoating of viral genome
D. Doubling
Answer» B. Penetration
93.

The location of first hexameric sequence typically found in pro-karyotic promoters is

A. at the transcription start site
B. approximately 35 bases upstream of the transcription start site
C. approximately 10 bases upstream of the transcription start site
D. approximately 25 bases upstream of the transcription start site
Answer» C. approximately 10 bases upstream of the transcription start site
94.

RNA populations can also be used as PCR templates after reverse transcription into

A. c DNA
B. t RNA
C. m DNA
D. r RNA
Answer» B. t RNA
95.

Poliovirus have single-stranded 'RNA' of

A. Negative polarity
B. Positive polarity
C. Neutral
D. Bipolar
Answer» C. Neutral
96.

Which of the following proteins first binds to TATA box during transcription?

A. TF II A
B. TF II D
C. TF II B
D. RNA polymerase
Answer» C. TF II B
97.

The type of recombination that commonly occurs between a pair of homologous DNA sequences is,

A. mutagenic recombination
B. site-specific recombination
C. replicative recombination
D. general recombination
Answer» E.
98.

After completion of a viral replication cycle number of progeny in host cell is, approximately

A. 100 virion
B. 200 virion
C. 50 virion
D. 40 virion
Answer» B. 200 virion
99.

Which 'DNA' does not have a double strand DNA ?

A. Poxviruses
B. Parvoviruses
C. HIV
D. HCV
Answer» C. HIV
100.

Process, one or both viruses infect cells, having mutation and produced nonfictional protein, called as

A. Recombination
B. Reassortment
C. Complementation
D. Transduction
Answer» D. Transduction