Question

Choose the correct set of labellings in the given diagram.

• A. x - generative cell, y - pollen tube, z - pollen tube nucleus
• B. x - generative cell, y - tube nucleus, z - pollen tube
• C. x - pollen tube, y - tube nucleus, z - generative cell
• D. x - tube nucleus, y - generative cell, z - pollen tube

Hint:

In a pollen grain, the generative cell produces sperm cells, the tube nucleus controls the pollen tube's growth, and the pollen tube delivers sperm cells to the ovule.

Answer 1

The Correct Option is B

Step 1: Understanding the parts of pollen grain.
In a pollen grain, the generative cell produces two sperm cells, the tube nucleus controls the growth of the pollen tube, and the pollen tube is the structure that grows down the style to deliver the sperm cells.
Step 2: Analyzing the options.
(A) x - generative cell, y - pollen tube, z - pollen tube nucleus: Incorrect. The generative cell is not in the pollen tube.
(B) x - generative cell, y - tube nucleus, z - pollen tube: Correct. This correctly labels the parts of the pollen grain.
(C) x - pollen tube, y - tube nucleus, z - generative cell: Incorrect. The pollen tube should be labeled as 'z', not 'x'.
(D) x - tube nucleus, y - generative cell, z - pollen tube: Incorrect. The generative cell should be labeled as 'x', not 'y'.
Step 3: Conclusion.
The correct answer is (B) x - generative cell, y - tube nucleus, z - pollen tube.