Read the following Assertion and Reason and choose the correct option. Assertion: The progressive decrease in the number of helper T-lymphocytes due to HIV infection leads to severe immuno-deficiency. Reason: This immuno-deficiency results in the patient being unable to overcome infections that are typically manageable, such as those caused by bacteria, viruses, fungi, and parasites.

Step-by-step solution

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. Simultaneously, HIV enters into helper T-lymphocytes (TH ), replicates and produce progeny viruses. The progeny viruses rele