Question

Name an event that is unique to angiosperms?

Answer 1

Double fertilization:

1. It is a characteristic feature of flowering plants. In process of double fertilization out of the 2 sperm nuclei, one sperm nucleus fuses with the egg nucleus to form an embryo (the process is called syngamy) & other fuses with the polar nuclei to form endosperm (the process is called triple fusion).
2. Since 2 kinds of fusion—syngamy & triple fusion—take place, the process is known as double fertilization.
3. In flowering plants during fertilization, pollens from male flowers are then dropped on the stigma of the female flower. Inside pollen grain, 2 pollen nuclei (male gametes) are then formed which gradually enter inside ovule by pollen tubes.
4. In the ovule one male nucleus fuses with the egg cell to form a zygote and the other fuses with the secondary nucleus or central nucleus to form the endosperm. As this fertilization is taking place two times, it is known as double fertilization.