Cell: The Unit of Life — BIO BOTANY STD 11 — Question

Cell surface membrane are able to transport individual molecules and ions. There are processes in which a cell can transport a large quantity of solids and liquids into cell endocytosis or out of cell exocytosis.1. Endocytosis: During endocytosis the cell wraps the cell surface membrane around the material and brings it into cytoplasm inside a vesicle. There are two types of endocytosis:

• Phagocytosis – Particle is engulfed by membrane, which folds around it and forms a vesicle. The enzymes digest the material and products are absorbed by cytoplasm.
• Pinocytosis – Fluid droplets are engulfed by membrane, which forms vesicles around them.

2. Exocytosis: Vesicles fuse with plasma membrane and eject contents. This passage of material out the cell is known as exocytosis. This material may be a secretion in the case of digestive enzymes, hormones or mucus.