Question

AIDS is caused by HIV principally infects
A. All lymphocytes
B. Activator B-cells
C. Cytotoxic T-cells
D. T-4 helper lymphocytes

Answer 1

Hint: AIDS and HIV are words that, although they are not the same, are used interchangeably. Essentially, the virus causing AIDS is HIV. It creates damage to the immunity function of the body, and the body becomes powerless on its own to fight off infections. It is a retrovirus and, as genetic material, has RNA.

Complete answer:
There is a long incubation time for HIV before it begins targeting the immune system (10 years). Macrophages in the blood are contaminated by HIV. When infected, the viral RNA breaks into the host cell and, with the assistance of a reverse transcription enzyme, produces DNA. This viral DNA then incorporates into the genome of host cells and, via the transcription process, produces several RNA copies. Then these RNAs form numerous copies of the virus which begin the infection in the same manner.
HIV also gets into the T lymphocytes around the same time and begins the same course of activities as it has in macrophages. This contributes to a decline in the number of lymphocytes with helper T. Thus, the body's immunity is considerably weakened. The immunity is diminished to such a degree that even mild infections cause the infected individual to suffer.

So, the correct answer is an option (D).

Note: With the help of a test called ELISA, which stands for 'Enzyme-Linked ImmunoSorbent Assay', HIV infection can be identified. So far, AIDS is incurable; HIV prevention is therefore the wisest choice. Some prevention includes the use of sterile needles, safe sex activity, i.e. the use of safety such as condoms, daily clinical check-ups, and monitor blood transfusion and pregnancy monitoring.