Question

Name the selectively permeable membrane.
Hence show how carbon dioxide and water move in and out of the cell.
In the same process name the term that refers to cellular repair of the plasma membrane. [5 MARKS]

Answer 1

Naming : 1 Mark
Explanation : 3 Marks
Naming : 1 Mark
1. The selectively permeable membrane is called the plasma membrane.
2. Substances like carbon dioxide and water move in and out of a cell by diffusion from the region of high concentration to a region of low concentration.
When the concentration of carbon dioxide and water is higher in the external environment than that inside of the cell, carbon dioxide and water moves inside the cell.
When the concentration of carbon dioxide and water is lower in the external environment than the inside of the cell, carbon dioxide and water moves out of the cell.

Due to diffusion and osmosis, which involves the constant entry and exit of molecules from the cytoplasm, the walls of the cell membrane undergoes extensive damage.
They need to be repaired on an ongoing basis.
Biogenesis is the term that refers to this constant cellular repair of the plasma membrane.