Describe the structure of sex chromosomes.

Explanation

(1) X-chromosome is longer, sub-metacentric chromosome with large amount of euchromation and smaller amount of heterochromatin.
(2) Y-chromosome is shorter, acrocentric with small amount of euchromatin and large amount of heterochromatin.
(3) X-chromosome has more genes and DNA, while Y-chromosome is genetically less active chromosome.
(4) Non-homologous regions of X- and Y-chromosomes contain X-linked and Y-linked genes respectively.