Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A : In lysogenic cycle the viral nucleic acid does not hamper the functions of host bacterium
Reason R : In lysogenic cycle the nucleic acid of phage gets incorporated into the host DNA and becomes a prophage, acting as a gene
In light of the above statements, choose the correct answer from the options given below

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true but R is NOT the correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Hint:

Lytic = "Lysis" (Death/Bursting).
Lysogenic = "Genes" (Integration/Stability).
A lysogenic bacteria is called a lysogen.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question explores the Lysogenic cycle, which is a temperate infection strategy used by certain viruses (like Phage Lambda), contrasting it with the destructive Lytic cycle.

Step 2: Detailed Explanation:

• Assertion Analysis: In the lysogenic cycle, the virus does not immediately kill the host. The host bacterium continues to grow, divide, and perform all its normal metabolic functions. The virus is essentially "hidden" or latent within the host. Thus, Assertion A is True.

• Reason Analysis: The reason for this peaceful coexistence is that the viral genome integrates itself into the bacterial chromosome via site-specific recombination. In this integrated state, it is called a prophage. It is replicated along with the host's DNA during cell division, effectively behaving like one of the host's own genes. Thus, Reason R is True.

• Relationship: The fact that the virus becomes an integrated, dormant part of the host's genetic material (Reason) is precisely why it does not interfere with or destroy the host's functions (Assertion).
Final Answer:
Both statements are correct, and the Reason provides the exact molecular explanation for the Assertion.