At which stage of HIV infection does one usually show symtomas of AIDS

Options

A. Within 15 days of sexual contact with an infected person
B. When the infected retro virus enters host cells
C. When HIV damages large number of helper T-lymphocytes
D. When the viral DNA is produced by reverse transcnptase

Answer

C

Explanation

T-lymphocyte receptors can recognise only antigen that bound to cell membrane proteins. These lymphocytes mediate CMI (cell mediated immunity). B-lymphocytes are the major effector molecules of humeral immunity. Erythrocytes are red blood cells. Thrombocytes or platelets secrete factors, that are involved in vascular repair.