Which of the following is present in a higher amount in the nucleus but in a lower amount in the chromosome?

The nucleolus is formed by . . . . . . .

Nucleolus is

Balbiani rings (puffs) are sites of:

Match the chromosome types based on the position of the centromere as shown in the standard classification:

Column-$I$ (Type)	Column-$II$ (Description)
$1$. Metacentric	$a$. Terminal centromere
$2$. Sub-metacentric	$b$. Sub-terminal centromere
$3$. Acrocentric	$c$. Middle centromere
$4$. Telocentric	$d$. Slightly away from the middle

$S$ - Statement: $RNA$ and protein molecules move between the nucleoplasm and the cytoplasm.
$R$ - Reason: Nuclear pores are present at several locations in the nuclear envelope of the nucleus.