Question

Identify the sequence of events which happens during germination of pollen grains. A. Secretion of stigmatic exudates B. Formation of callose plug in pollen tube C. Adherence of pollen grain to stigma D. Entry of pollen tube into ovule E. Degradation of stigmatic cells by cutinase. Choose the correct answer from the options given below:

• A. C, B, E, D, A
• B. C, A, B, E, D
• C. A, D, C, B, E
• D. C, A, E, B, D

Hint:

Remember the correct order: adherence to stigma, exudate secretion, stigmatic cell degradation, callose plug formation, and finally pollen tube entry.

Answer 1

The Correct Option is D

Step 1: Concept
Plant reproduction and pollen grain germination

Step 2: Meaning
Understanding the sequence of events that occur during the germination of pollen grains, specifically focusing on the steps from adherence to stigma to penetration into ovule.

Step 3: Analysis
The correct answer is D. C, A, E, B, D. The sequence of events includes: 1) Adherence of pollen grain to stigma (C), 2) Secretion of stigmatic exudates (A), which can help in the germination process, 3) Degradation of stigmatic cells by cutinase (E), allowing the pollen tube to grow through the stigma, 4) Formation of callose plug in pollen tube (B), which helps in guiding the growth towards the ovule, and finally 5) Entry of pollen tube into ovule (D).

Step 4: Conclusion
The sequence of events during germination of pollen grains is accurately represented by option D. Final Answer: (D)