Question

Are Barr bodies heterochromatin?

Answer 1

Heterochromatin:

1. Chromatin refers to a complex of DNA and protein that forms the chromosomes.
2. The densely-packed region of chromatin is known as heterochromatin. It is transcriptionally inactive.
3. This region of the chromosome is found in the eukaryotic genome and stains darkly, occupying the majority of the genome.

Barr bodies:

1. In humans, females possess two X chromosomes.
2. The somatic cells are not associated with sexual reproduction; hence one of the two X chromosomes is inactivated by a process called ‘lyonization’.
3. The inactive X chromosome is referred to as a ‘Barr body’.
4. Barr bodies are heterochromatin. They appear dense and darkly stained when viewed under a microscope.