Question

The selective digestion of cytoplasmic cell organelles by the lysosome is called a
A. Osmotrophy
B. Autophagy
C. Heterophagy
D. Autolysis

Answer 1

Hint:
1. The process of digestion of cell organelle by lysosome is known under autophagy.
2. It is the normal physiological process conducted to maintain a balance between the formation and destruction of different cell components.
Complete answer:
1. Osmotrophy is the simple uptake of nutrients by the process of osmosis ( movement of solute from its high concentration to low concentration through a semipermeable membrane), and the organisms that undergo the process of osmotrophy are known as somatotrophs.
2. It is also known as osmotic nutrition. It mainly includes bacteria, protists, and fungi.
3. Heterophagy is defined as the ingestion and digestion of extracellular material from the extracellular space by lysosomes.
4. In heterophagy the activity of lysosomes does not damage any cell organelle or cytoplasmic
constituents, it engulfs the extracellular material and destroys them. These types of activities are shown by the kupffer cells of the liver.
5. In the process of autolysis the lysosomes digest all the cell organelles and the cytoplasm by the
enzymes hence complete destruction of cells takes place in autolysis.
6. Autolysis is mainly seen in infected cells to prevent further spread of infection and protect the
healthy cells from infection.
7. In autophagy the lysosomal enzymes act on the cell organelles of the cytoplasm and digest these cell organelles. In this way there is a physiological and chemical balance maintained inside the cell.
Hence the process in the process of Autophagy, lysosomes selectively digest the cytoplasmic cell
organelles.

So, the correct answer is “Option B Autophagy”.

Note:
1. The process by which the extracellular material taken into the cell is known as endocytosis.
2. Heterophagy is mainly seen in the immune response cells.