Question

Which cellular organelles are involved in initiation of intrinsic pathway of apoptosis?
ER
Lysosome
Mitochondria
All of the above

Answer 1

Hint:- Apoptosis, which happens in multicellular animals, is a type of programmed cell death. During growth, apoptosis kills cells, destroys potentially cancerous and virus-infected cells, and retains equilibrium in the body.

Complete step-by-step solution:-
The death of cells that happens as a natural and regulated part of the growth or development of an organism is referred to as apoptosis. Apoptosis is a highly regulated and controlled process that can not be halted once it has begun and offers benefits during the life cycle of an organism. It is initiated by one out of two pathways, intrinsic or extrinsic pathway. In both cases, the cell kills itself: In the extrinsic pathway because of signals from other cells, whereas in the intrinsic pathway because it detects cell stress. Both pathways perform cell death by activating caspases (an enzyme or protease) that degrade proteins.
Intrinsic pathways are also called mitochondrial pathways as mitochondria are the origin of signal initiation of the activation of the capsule through different methods. ER also regulates apoptosis both by sensitizing mitochondria to several extrinsic and intrinsic death stimuli and by inducing its signals of cell death. Lysosome secrets lysosomal proteases into the cytosol, where they contribute to the upstream mitochondrial apoptotic cascade.
Therefore the answer will be option D, ‘all of the above’.

Note:-
Example of apoptosis: At the time of its metamorphosis into a frog, the resorption of the tadpole tail, gills, and even fins happen by apoptosis. The development of the fingers and toes of the foetus involves the destruction of the tissue between them, by apoptosis.