Centromere is part of

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

The centromere is also known as $.......$.

Depending upon size and centromere position,the $46$ chromosomes have been divided into a number of groups.

Distinguish between: Euchromatin and Heterochromatin.

If the centromere is situated slightly away from the middle of the chromosome, resulting in one shorter arm and one longer arm, such a chromosome is called .......