Chromosome: Justify- euchromatin represents genetically active parts of chromosomes.
Genetically active parts of chromosome undergoes RNA production and protein synthesis, euchromatin represents genetically active parts of chromosomes because:
In euchromatin, DNA-histone protein interactions are weaker, keeping euchromatin open and less coiled compared to heterochromatin. The loose chromatin structure of euchromatin allows RNA polymerase to access DNA for active transcription, leading to increased RNA production and higher protein synthesis.
Cells can be classified based on the type of chromatin they predominantly contain:
Cells Rich in Euchromatin:
- Definition: Euchromatin is loosely packed, transcriptionally active chromatin.
- Characteristics:
- Lightly stained under the microscope.
- Actively engaged in gene transcription.
- More accessible to transcription factors and RNA polymerase.
- Examples:
- Neurons (highly active in protein synthesis).
- Embryonic stem cells (require extensive gene expression for differentiation).
- Hepatocytes (liver cells) (involved in metabolism and protein production).
- Germ cells (spermatogonia, oocytes) (undergoing developmental changes).
Cells Rich in Heterochromatin:
- Definition: Heterochromatin is densely packed, transcriptionally inactive chromatin.
- Characteristics:
- Darkly stained under the microscope.
- Contains silenced or less active genes.
- Provides structural stability and gene regulation.
- Examples:
- Lymphocytes (resting B and T cells) (in a quiescent state until activated).
- Fibroblasts (in resting state) (low metabolic activity).
- Erythrocytes (mature RBCs) (completely lack transcriptional activity).
- Sperm cells (highly condensed DNA for stability).
- Satellite cells in skeletal muscle (remain quiescent until activated).
