Definition
Apoptosis means dropping off or falling off.
OR
The naturally cell death programme is called apoptosis.
Mechanism of Apoptosis
- Apoptosis is thought to require the activation of a specific set of genes.
- Death by apoptosis is characterized by over all compaction of the cell and its nucleus by the orderly dissection of the chromatin by special DNA splitting endonuclease and the rapid engulfment of the dying cells by phagocytes.
- Apoptosis appears to be mediated primarily by the release of ca++ and the activation of certain protein kinesos.
- Apoptosis is common during the embryonic development the growth of the cells between finger that are no longer needed undergoes apoptosis.
- It also occurs in adult tissues where it destroys the cells that have potential to develop the malignant tumor.
Definition
The abnormalities in the process of meiosis are termed as meiotic error.
Non-Disjunction
The failure in the separation of the homologous chromosome due to meiotic error is known as non-disjunction.
Heteroploidy
A change in the normal chromosome number is called heteroploidy.
There are two types of Heteroploidy
1. Aneuploidy
2. Polyploidy
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