Question

Heterochromatic regions found at multiple discrete sites located between the centromeres and telomeres which show with methylated DNA at CpG islands in regulatory regions are called ______ heterochromatin.

1) activated
2) constitutive
3) facultative
4) euchromatic

Answer 1

The heterochromatic regions between centromeres and telomeres with methylated DNA at CpG islands are known as constitutive heterochromatin, which is generally inactive in gene expression.

Step-by-step explanation:

The heterochromatic regions found at multiple discrete sites located between the centromeres and telomeres, which show with methylated DNA at CpG islands in regulatory regions, are called constitutive heterochromatin. Constitutive heterochromatin is generally transcriptionally inactive due to its highly condensed state and often contains repeating DNA sequences. It is usually found in regions like centromeres and telomeres, and its DNA is typically more heavily methylated, which contributes to its inactivity in gene expression. On the other hand, facultative heterochromatin refers to regions that can transition between active and inactive states, undergoing changes to become transcriptionally active or silent as needed during development or in response to environmental cues.