Question

Programmed cell death is
A. Cell lysis
B. Autotomy
C. Apoptosis
D. None of the above

Answer 1

Hint: The process is cellular suicide which removes cells during development and eliminates the cancerous and virus-infected cells and therefore maintains the balance in the body.

Complete answer:
> Cell lysis-
It is the breakdown of the cell by causing damage to its outer membrane (plasma membrane). It is often done by viral, enzymic or osmotic mechanisms. Fluid which contains the contents of the lysed cells is called 'lysate'. Cell lysis is usually used in western and southern blotting to analyse proteins, lipids, nucleic acids and protein purification etc. Some or all membranes are lysed which depends upon the detergent used. Also, if only the cell membrane is lysed then gradient centrifugation method can be used to collect the organelles from the cell. This option A is not the correct one since it is not a programmed cell death but it is breakdown of cell membrane.

> Autotomy-
It is the ability of certain animals to release their body parts especially when they are being attacked by the predator, for example, it is seen in lizards that when it is seized by the predator then it breaks off the tail. It is also found in worms, salamanders and spiders. The cast off part also sometimes gets regenerated. This option B cannot be the right answer as it is not a programmed cell death, this process is completely different.

> Apoptosis-
It is a form of programmed cell death, it occurs in multicellular organisms. Due to biochemical events there are characteristic changes in cells and death happens like the shrinkage of cells, nuclear fragmentation, chromosomal DNA fragmentation etc. This option C is the most correct one as it is a process where there is programmed cell death and what is asked in the question.

Hence, the correct answer is option (C).

Note: Autotomy is the ability of some animals which release their body parts like in case of lizards, Cell lysis means the lysis of the cell which cause damage to the plasma membrane, Apoptosis means the programmed death of cell in the multicellular organisms. In the question, programmed cell death is asked which makes apoptosis the correct one.