Which of the following cells are infected in a person suffering from $AIDS$?
$CD_{4}$ receptor cells
$CD_{8}$ receptor cells
Killer $T$ cells
Germ cells
Oral polio vaccine and hepatitis first dose is given to a child at
Match the following columns
Column-I | Column- II |
$(A)$ Pill | $(1)$ Intra uterine device |
$(B)$ Condom | $(2)$ Prevents ovulation |
$(C)$ Vasectomy | $(3)$ Prevents sperms from reaching to cervix |
$(D)$ Cu - T | $(4)$ Semen contains no sperms |
The concept that “Population tends to increase geometrically while food supply increases arithmetically'' was put forward by
In which one of the following the birth rate is high & death rate is normal