Question

Fertilization is an important event in angiosperm, which involves several critical activities. Below are a few major steps of fertilization in plants. Arrange them from the beginning to the last, systematically. 
• [(A).] Pollen germination. 
• [(B).] Anthesis followed by pollination. 
• [(C).] Fertilization. 
• [(D).] Penetration of the ovule. 
Choose the correct answer from the options given below: 
 

• A. (A), (B), (C), (D)
• B. (A), (C), (B), (D)
• C. (B), (A), (D), (C)
• D. (C), (B), (D), (A)

Hint:

Remember that angiosperms undergo double fertilization.
This process simultaneously produces the embryo (fertilization of egg) and its food source (fertilization of polar nuclei to form endosperm).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Fertilization in flowering plants (angiosperms) involves a series of physical and biochemical steps that lead to double fertilization.

Step 3: Detailed Explanation:
Let us organize the steps of the fertilization process in chronological order:
1. Anthesis followed by pollination (B): Anthesis is the opening of the flower, making the reproductive organs accessible.
This is followed by pollination, which is the transfer of pollen grains from the anthers to the receptive surface of the stigma.
2. Pollen germination (A): Once on the stigma, the pollen grain absorbs water and nutrients, germinating to produce a pollen tube.
3. Penetration of the ovule (D): The pollen tube grows down through the style and ovary toward the ovule.
The tube enters the ovule, typically through the micropyle, to reach the embryo sac.
4. Fertilization (C): The tip of the pollen tube ruptures, releasing two male gametes into the embryo sac.
One gamete fuses with the egg cell to form the diploid zygote, while the other fuses with the polar nuclei to form the triploid endosperm.
Therefore, the correct chronological sequence is: (B) \(\rightarrow\) (A) \(\rightarrow\) (D) \(\rightarrow\) (C).

Step 4: Final Answer:
The correct chronological sequence is Option (C).