Arrange the given steps involved in replication of retrovirus in correct sequence.
(A) Viral DNA gets incorporated into host cell’s DNA
(B) RNA genome of the virus replicates to form viral DNA
(C) Virus enters into macrophages of the host
(D) Macrophages continue to produce large number of viruses
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (C), (B), (A), (D)
HIV is a retrovirus. Its genome is RNA, and it makes DNA from the RNA with the enzyme reverse transcriptase.
(C) Virus enters into macrophages of the host — first. The virus must get inside a host cell before anything else can happen.
(B) RNA genome of the virus replicates to form viral DNA — second. Inside the macrophage, reverse transcriptase makes viral DNA from the viral RNA.
(A) Viral DNA gets incorporated into host cell’s DNA — third. The viral DNA can be joined to the host DNA only after it has been made.
(D) Macrophages continue to produce large number of viruses — last. The host DNA now directs the cell to make virus particles, so the macrophage works as a virus factory.
NCERT Extract:
AIDS – …
Figure 7.6 Replication of retrovirus