<u>Answer:</u>
<u> It is a type of endocytosis in which a cell engulfs a particle in a vacuole.</u>
<u>Explanation:</u>
There are 2 processes by which cells uptake and release materials.
These are:
- Exocytosis
- Endocytosis
<u>EXOCYTOSIS:</u>
It is a process by which cells release materials inside them to the external environment.
<u>ENDOCYTOSIS:</u>
It is a process by which cells bring materials inside them from the external environment. It is the opposite of exocytosis.
Endocytosis is of different types including <u>phagocytosis, pinocytosis and receptor-mediated endocytosis.</u>
<u>PHAGOCYTOSIS</u>
Phagocytosis involves the phenomenon in which a cell engulfs a particle in a vacuole. The particle may be a disease causing microorganism, or cell of the body. This process can be conceptualized as "cellular eating".
<u>EXAMPLE:</u>
Macrophages consuming bacterium Mycobacterium tuberculosis is an example of phagocytosis.
<u>PINOCYTOSIS:</u>
It is the process by which cells uptake liquid substances. It can be thought of as "cellular drinking"
<u>RECEPTOR-MEDIATED ENDOCYTOSIS:</u>
It is a process by which cells uptake hormones, metabolites and other substances. It is performed by cells which possess a receptor for that substance. It involves the inward invagination of cell membrane after the binding of substance and its receptor.
Coming back to answer choices,
<em><u>It is a type of endocytosis in which a cell engulfs a particle in a vacuole.</u></em>
This is the correct answer choice as it describes the process of phagocytosis.
<u>It is a type of exocytosis in which a cell engulfs a particle in a vacuole.</u>
This is the wrong answer choice as phagocytosis is an endocytic process.
<u> It is a type of endocytosis in which extracellular fluid is taken into the cell in tiny vescicles.</u>
This is the wrong answer choice as this answer choice describes the process of pinocytosis and not phagocytosis.
<u>It is a type of exocytosis in which extracellular fluid is taken into the cell in tiny vesicles. </u>
This is the wrong answer choice. It does not describe phagocytosis. Phagocytosis is an endocytic process and involves the internalization of cells and pathogens.
