Q.Differentiate between X-chromosome and Y-chromosome with reference to -

X chromosome has a much longer non-homologous region than the Y chromosome. X chromosome is metacentric/sub-metacentric; Y chromosome is acrocentric.

The X and Y chromosomes differ in the size of their non-homologous segments and in centromere position (X is larger and sub-metacentric; Y is smaller and acrocentric).

(a) Length of non-homologous region: The X chromosome is large and carries an extensive non-homologous region bearing many genes unrelated to sex determination (e.g. genes for haemophilia, colour blindness). The Y chromosome is much smaller, and its non-homologous region is comparatively short, carrying far fewer genes, chiefly those involved in male sex determination (such as the SRY gene). …