Rearrange the events of life cycle of a retrovirus.
A. New viral RNA produced by infected cell
B. Reverse transcription
C. New virus particles inject into other cells
D. Viral RNA introduced into the cell
E. Viral DNA incorporates into host genome
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → D, B, E, A, C
D. Viral RNA introduced into the cell — first. The retrovirus (such as HIV) enters the host cell and releases its RNA genome.
B. Reverse transcription — second. The enzyme reverse transcriptase copies the viral RNA into DNA.
E. Viral DNA incorporates into host genome — third. The new viral DNA joins the host cell’s DNA and directs the cell to make virus.
A. New viral RNA produced by infected cell — fourth. The infected cell makes new viral RNA and proteins, and new virus particles are put together.
C. New virus particles inject into other cells — last. The new viruses leave the cell and infect other cells, and the cycle goes on.
NCERT Extract:
AIDS – “… After getting into the body of the person, the virus enters into macrophages where RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase. This viral DNA gets incorporated into host cell’s DNA and directs the infected cells to produce virus particles (Figure 7.6). The macrophages continue to produce virus and in this way acts like a HIV factory.”
Figure 7.6 Replication of retrovirus