Question

Read the following statements regarding phases of growth:
A. Meristematic phase involves active cell division.
B. Elongation phase involves vacuolation and cell enlargement.
C. Mature cells attain maximum size and differentiation.
Choose the correct answer from the options given below:

• A. Only A and B are correct
• B. Only B and C are correct
• C. Only A and C are correct
• D. A, B and C are correct Correct Answer: (D) A, B and C are correct

Hint:

When answering questions about plant growth phases, trace the structural changes mentally: Cell Division (A) naturally creates a tiny new cell $\rightarrow$ Vacuolation (B) stretches that tiny cell out like a balloon $\rightarrow$ Differentiation (C) thickens its walls to fix it into its final adult form. This logical flow helps confirm that all three descriptions are true!

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The progression of a plant cell from its origin in a meristem to its final structural form follows a highly ordered developmental path. This sequence involves three consecutive phases: the meristematic phase, the elongation phase, and the maturation phase. Each phase features distinct physical and physiological changes within the cells.

Step 2: Detailed Explanation:
Let's evaluate the scientific correctness of each statement independently: - Statement A: "Meristematic phase involves active cell division." (Correct) Cells in the meristematic zone are constantly undergoing mitotic cell division. They are tightly packed, thin-walled, and structurally simple, acting as the continuous source of new cells for the plant body. - Statement B: "Elongation phase involves vacuolation and cell enlargement." (Correct) Directly behind the dividing zone, cells stop actively splitting and begin to rapidly grow in size. This expansion is driven by increased vacuolation (the fusion and enlargement of fluid-filled vacuoles) and the systematic deposition of new cellulose fibers into the expanding cell wall. - Statement C: "Mature cells attain maximum size and differentiation." (Correct) Once cells leave the elongation zone, they enter the maturation phase. Here, they reach their maximum physical dimensions, their cell walls undergo maximal thickening, and they undergo differentiation—a process where they take on permanent structural shapes and specialized biological functions (e.g., forming protective bark or water-conducting pipes). Since statements A, B, and C are all completely factually correct, option (D) is the correct choice.

Step 3: Final Answer:
The correct option is (D) A, B and C are correct.