AIDS is characterised by a sharp reduction is
Helper $T-$ cells
Killer $T-$ Cells
Suppressor $T-$ Cells
$B-$ lymphocytes
The pathogens of genera, Microsporum, Trichophyton and Epidermophyton are responsible for
Which one of the following diseases is caused by virus?
$HIV$ decreases natural immunity of the body by
‘Black death' is related with