Concept:HIV is a retrovirus that specifically attacks cells of the immune system, particularly Helper T‑lymphocytes.
Explanation:HIV enters the body and first infects macrophages.
Inside macrophages, the viral RNA is converted into DNA by the enzyme reverse transcriptase.
This viral DNA then integrates into the host cell’s DNA and directs the production of new virus particles.
The new viruses are released and enter Helper T‑lymphocytes (also called T
H cells) in the blood.
Inside these helper cells, the virus continues to replicate and produce more viral particles.
As a result, the number of Helper T‑lymphocytes gradually decreases.
A drop in these cells weakens the immune system, making the body unable to mount an effective immune response.
Thus, the primary target of HIV infection is Helper T‑lymphocytes.
Answer:B. Helper T‑lymphocytes