Question

Explain double fertilization.

Hint:

Double fertilization = Syngamy (zygote) + Triple fusion (endosperm).

Answer 1

Step 1: Definition.
Double fertilization is a unique feature of angiosperms in which two fusions occur inside the embryo sac.
Step 2: Process.
1. One male gamete fuses with the egg cell → forms diploid zygote (syngamy).
2. Second male gamete fuses with two polar nuclei → forms triploid primary endosperm nucleus (PEN).
Step 3: Significance.
- Zygote develops into embryo.
- PEN develops into endosperm, which nourishes the embryo.
Step 4: Conclusion.
Double fertilization ensures formation of both embryo and nutritive endosperm in angiosperms.