Facultative heterochromatin is heterochromatin

thatcontains

a. sequence inactive in one cell type but active

inothers.

b. DNA sequenes that are not transcribed in any

celltype.

c. a mixuture of heterochromatin and euchromatin

d. heterochromatin that function in ways other than

fortransription.

a. sequence inactive in one cell type but active in others.

Explanation:

Heterochromatin is the chromatin that is not transcribed. It is present in two forms: facultative heterochromatin and constitutive heterochromatin.

Facultative heterochromatin has the unique ability to be active and appear euchromatic in some cells. In some other cells, the same chromatin is inactive and heterochromatic in nature. Facultative heterochromatin is cell-specific with respect to the pattern of its expression. When a particular segment of a chromosome becomes heterochromatin, all of its progeny cells would maintain it as heterochromatin. However, the other cells may not maintain the same region of the chromosome as heterochromatin.