What is constitutive heterochromatin and facultative heterochromatin?

Heterochromatin:

1. Heterochromatin is a type of DNA that is tightly packed or condensed and occurs in a variety of shapes and sizes.
2. Heterochromatin has been linked to a variety of functions, including gene control and chromosome integrity protection.
3. Between the two extremes of constitutive heterochromatin and facultative heterochromatin, several variants exist on a range.
4. Gene expression is influenced by both of these extremes.

Constitutive heterochromatin:

1. The term "constitutive heterochromatin" refers to the DNA sections of the chromosome that remain constant throughout the cell cycle.
2. It is a type of chromatin that contains genes and can be converted to euchromatin.
3. It is usually repetitive and forms structural functions such as centromeres or telomeres.
4. Constitutive heterochromatin is a stable kind of heterochromatin.

Facultative heterochromatin:

1. Facultative heterochromatin refers to DNA areas where genes have been silenced by changes.
2. A sex chromatin body, found in the cells of species with homogametic sex, is an example of facultative chromatin
3. Information is stored in the facultative heterochromatin.
4. In addition, facultative chromatin formed during cell differentiation processes serves as a mechanism of switching off the activity of several genes which is not necessary for the cell of such specialization.
5. Facultative heterochromatin is a reversible kind of heterochromatin.