Question

Choose the correct option regarding the statements given below.

Assertion (A): Amoeba does not have any specialised organ for nutrition.
Reason (R): In some single-celled organisms, nutrients are taken in by the entire surface through the process of diffusion.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both statements are true but (R) is not the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. Both the statments are false.

Answer 1

The correct option is A Both (A) and (R) are true and (R) is the correct explanation of (A).

$\bullet$ The body design of single-celled organisms is very simple as a single cell performs all the life sustaining processes. As the complexity of the body design increases, different parts become specialised to perform different functons.

$\bullet$ In some organisms like amoeba, the food is taken in by the entire body surface with the help of pseudopodia.
Firstly, amoeba uses pseudopodia to get in close proximity to the food particle and then fuses with the food particle forming a food vacuole. Inside its body, the food particles are broken down to simpler components by certain chemical reactions. Digestive enzymes act upon them. Thereafter the nutrients from the digested food are absorbed in the cytoplasm of the cell via the process of diffusion. And the undigested food particles are removed from the body.