What are the different types of chromatin?
Chromatin exists in two forms: heterochromatin (condensed) and euchromatin (extended). The primary protein components of chromatin are histones that help to organize DNA into “bead-like” structures called nucleosomes by providing a base on which the DNA can be wrapped around.
What is heterochromatin and euchromatin?
Heterochromatin is defined as the area of the chromosome which is darkly stained with a DNA specific stain and is in comparatively condensed form. Euchromatin is defined as the area of the chromosome which is rich in gene concentration and actively participates in the transcription process.
Is heterochromatin light or dark?
During interphase, most of the chromatin takes up light stain but a small amount of chromatin in eukaryotic nucleus appears very dark under microscope. The light areas are euchromatin while the dark patches are heterochromatin. It is thought that euchromatin is in more hydrated and loosely arranged condition.
What is stained chromatin?
Mixtures of polychrome methylene blue-eosin Y (i.e., Giemsa stain) are widely used in biological staining. They induce a striking purple coloration of chromatin DNA (the Romanowsky-Giemsa effect), which contrasts with the blue-stained RNA-containing cytoplasm and nucleoli.
What is the main function of heterochromatin?
Transcriptionally inactive heterochromatin plays a vital role in sustaining stable structure of specialized chromosomal regions with repetitive DNA, such as centromeres and telomeres. Loss of integrity in these chromosomal areas can lead to detrimental effects and drive cancer development.
What is the difference between euchromatin and heterochromatin quizlet?
What is the difference between euchromatin and heterochromatin? Euchromatin has regular cycles of condensation and decondensation between interphase and mitosis, whereas heterochromatin remains highly condensed throughout cycle (except for at replication).
Why is heterochromatin darkly stained?
The constitutive heterochromatin gets dark stained because of the exceptionally consolidated nature of the DNA in these regions. This heterochromatin consists of a high number of repetitive nucleotides. Facultative heterochromatin is the consequence of genes that are silenced through histone deacetylation process.