Name the type of human cell HIV attacks on its entry into the body. Explain the events that occur in the cell which further lead to cause immuno deficinency syndrome.

Explanation

(i) On its entry into the body, HIV attacks macrophages.
Lifecycle of HIV- (i) After getting into the body of a person, the virus enters into macrophages, where RNA replicates and forms viral DNA with the help of enzyme reverse transcriptase.
(ii) The viral DNA gets incorporated into the host cell's DNA and directs the infected cells to produce viruses.
(iii) The macrophages continue to produce virus that enter the helper T-lymphocytes.
(iv) The number of helper T-lymphocytes progressively decrease in the body of the infected persons.
(v) Thus, the person suffers form various pathogens like Mycobacterium, viruses and parasites like Toxoplasma.