Robert Brown is well known for the discovery of . . . . . . .

$A$: Chromosomes are responsible for hereditary traits in all living organisms.
$R$: Genes are microscopic structures that contain chromosomes.

The shape of the chromosome is determined by

$A$ chromosome in which the $centromere$ is situated near one end is known as

In nucleoplasm,a conspicuous body of spherical shape attached to a particular chromosome on a definite position is called

What are chromosomes with arms of equal length called?