MCQOPTIONS

Explore topic-wise MCQs in Vector Biology.

This section includes 17 Mcqs, each offering curated multiple-choice questions to sharpen your Vector Biology knowledge and support exam preparation. Choose a topic below to get started.

1.	Which of the following properties is due to lysogenic conversion by phages?
A.	Toxin production in Corynebacterium diphtheriae
B.	Toxin production in Clostridium botulinum types C and D
C.	Antigenic variation in Salmonella anatum
D.	All of the above
Answer» E.

2.	Which of the following is/are synthesized from late mRNA?
A.	Phage structural proteins
B.	Proteins that help with phage assembly without becoming part of the virion structure
C.	Proteins involved in cell lysis and phage release
D.	All of the above
Answer» E.

3.	In viruses with envelopes
A.	the envelope and the embedded proteins are encoded by the viral nucleic acid
B.	the envelope is derived from the host but it contains embedded proteins coded by the viral nucleic acid
C.	the envelope is coded by the viral nucleic acids, but the proteins come from the host's membrane proteins
D.	the envelope and its imbedded proteins are derived from the host's membranes
Answer» C. the envelope is coded by the viral nucleic acids, but the proteins come from the host's membrane proteins

4.	Which capsid symmetry is exhibited by most of the phages?
A.	Icosahedral
B.	Helical
C.	None of these
D.	Complex
Answer» B. Helical

5.	Contractile sheath of the tail is present in which of the following phages?
A.	T2
B.	T3
C.	All of these
D.	P22
Answer» B. T3

6.	Which of the following bacteria can be typed by phage typing method?
A.	Salmonella typhi
B.	Staphylococcus aureus
C.	All of these
D.	Vibrio cholerae
Answer» D. Vibrio cholerae

7.	__________ protein keeps the prophage dormant and prevents virus reproduction.
A.	Promotor
B.	Operator
C.	Enhancer
D.	Repressor
Answer» E.

8.	WHAT_ARE_STICKY_ENDS??$
A.	Ends of M13 vector
B.	12 nucleotide stretch in lambda phage
C.	The replicated product phage DNA
D.	Ends on two sides of origin
Answer» C. The replicated product phage DNA

9.	APPROXIMATE_SIZE_OF_LAMBDA_PHAGE_IS________?$
A.	23 kb
B.	100 kb
C.	49 kb
D.	12 kb
Answer» D. 12 kb

10.	Which of the following statements is not true in the context of infection by an M13 phage?
A.	Lytic phage
B.	Lysogenic phage
C.	New phage particles are continually synthesized
D.	The DNA is not integrated in host genome
Answer» B. Lysogenic phage

11.	Which infection cycle is characterized by retention of the phage DNA molecule in the host bacterium for many thousands of cell division?
A.	Lysogenic cycle
B.	Lytic cycle
C.	Integrative Phase
D.	Protein synthesis
Answer» B. Lytic cycle

12.	Which is a reason of instability of phage DNA molecule in the host cell in a lytic cycle?
A.	The huge size of phage DNA
B.	Inability of replicative enzymes
C.	Immediate synthesis of capsid
D.	Lytic cycle inefficiency
Answer» D. Lytic cycle inefficiency

13.	The cycle which is completed quickly in the infection by a phage is ________
A.	Lysogenic
B.	Lytic
C.	Replication
D.	Capsid formation
Answer» C. Replication

14.	The replication of phage DNA molecule is associated with which step in the infection cycle of a bacteriophage?
A.	First step
B.	Second step
C.	Third step
D.	Preparation stage
Answer» C. Third step

15.	Which of the following is an example of head-and-tail bacteriophage?
A.	M13
B.	Lambda phage
C.	Pbr322
D.	M16
Answer» C. Pbr322

16.	What is the capsid (protective coat) of the bacteriophage made up of?
A.	DNA
B.	RNA
C.	Protein
D.	Organic acids
Answer» D. Organic acids

17.	Which of the following is not true for a bacteriophage?
A.	A very simple structure
B.	Consist either DNA or RNA
C.	Bacteriophages are viruses
D.	Complex structure that infects bacteria
Answer» E.