The $Feulgen$ reaction is used to stain which of the following?

The puffs and rings are associated with the

Match the parts of the chromosome given in Column $I$ with their explanation in Column $II$:

Column $I$ (Chromosome)	Column $II$ (Explanation)
$1$. Centromere	$a$. Disc-shaped plate where spindle fibres get attached during cell division.
$2$. Secondary constriction	$b$. Long unbranched slender highly coiled $DNA$.
$3$. Kinetochore	$c$. Place where $2$ chromatids are joined together.
$4$. Chromatonema	$d$. Nucleolus gets organised at this place.

Choose the correct answer from the following options.

$A$ chromosome having the centromere in the middle is called .......

The point at which the polytene chromosomes appear to be attached together is known as

The composition of chromatin material is: