The . . . . . . is a primary constriction.

Read the following statements $:-$
$(i)$ Centromere is present in the middle of the chromosomes and forms two equal arms.
$(ii)$ Chromosome has a terminal centromere.
$(iii)$ Centromere lies close to the end of the chromosome forming one extremely short and one very long arm.
$(iv)$ Centromere lies slightly away from the middle of the chromosome resulting in one shorter arm and one longer arm.
Select the correct option as per the codes given below $:-$

Explain why the nucleus is considered the central point of all activities of the cell.

The polytene chromosomes were discovered for the first time in

$A$ chromosome with a sub-terminal centromere is known as .......

The pars granulosa of the nucleolus is primarily composed of: