Question

Following are the diagrams of entry of pollen tube into ovule. Identify the type A and B.
 
Give any four points of significance of double fertilization. 
 

Hint:

Double fertilization is unique to angiosperms; porogamy is the most common pollen tube entry.

Answer 1

i. Types of Pollen Tube Entry:
- Type A: Porogamy (pollen tube enters via micropyle).
- Type B: Chalazogamy (pollen tube enters via chalaza).
ii. Significance of Double Fertilization:
1. Ensures formation of both embryo (from egg fertilization) and endosperm (from polar nuclei fertilization).
2. Provides nutrition to developing embryo via endosperm.
3. Enhances reproductive efficiency in angiosperms.
4. Promotes genetic diversity through two fertilization events.
Answer: i. A: Porogamy, B: Chalazogamy; ii. Embryo/endosperm formation, nutrition, efficiency, genetic diversity.