Question

Which of the following statements is correct with reference to vacuoles?

• A. It is membrane bound and contains storage proteins and lipids.
• B. It is membrane bound and contains water and excretory substances.
• C. It lacks membrane and contains air.
• D. It lacks membrane and contains water and excretory substances.

Hint:

Vacuoles play a crucial role in maintaining turgor pressure in plant cells.

Answer 1

The Correct Option is B

Vacuoles are membrane-bound and contain water and excretory substances.

(A) It is membrane bound and contains storage proteins and lipids - Incorrect: While vacuoles are membrane-bound, they primarily store water, not proteins/lipids.

(B) It is membrane bound and contains water and excretory substances - Correct: Vacuoles are tonoplast-bound organelles containing cell sap with water, ions, and waste products.

(C) It lacks membrane and contains air - Incorrect: Vacuoles always have membranes (tonoplast).

(D) It lacks membrane and contains water and excretory substances - Incorrect: All vacuoles are membrane-bound structures.

The correct answer is (B), as vacuoles are membrane-bound sacs containing cell sap with water and metabolic wastes.

Answer 2

Vacuoles are membrane-bound organelles found in both plant and animal cells, although they are more prominent in plant cells. In plant cells, the vacuole typically contains water, ions, and organic compounds and serves to maintain turgor pressure. This pressure helps keep the plant cell rigid and structurally intact. Excretory substances, including waste products, are stored in vacuoles, especially in the case of plants, which do not excrete waste products like animals. Vacuoles are also involved in storing nutrients, sequestering toxic substances, and sometimes in detoxification.

• (A): Vacuoles don't generally store proteins and lipids in most cells. Storage of proteins and lipids occurs in other organelles like lipid droplets or protein storage vacuoles.
• (C): Vacuoles are membrane-bound organelles; they do not lack membranes.
• (D): Vacuoles do not contain air, but instead store substances like water, ions, and waste materials.

Option (B) is the correct answer because it accurately describes the function and structure of vacuoles.