Question

Explain the post-fertilisation events in an organism.

Answer 1

Post-fertilisation events are the events that occur after the formation of the zygote. They include the following:

1. Zygote formation and development: After fertilisation, a diploid zygote is formed. Depending on the organism, it may develop inside or outside the body of the parent.
2. Embryogenesis: The zygote undergoes repeated mitotic divisions and develops into an embryo.
3. Cell differentiation: The cells of the developing embryo become specialised and form different tissues and organs.
4. Development of the young one: In oviparous animals, development takes place inside the egg laid outside the body. In viviparous animals, the embryo develops inside the female body and the young one is born.
5. Post-fertilisation changes in flowering plants: The zygote develops into an embryo, the ovule develops into a seed, and the ovary develops into a fruit.

Thus, post-fertilisation events lead to the development of the zygote into an embryo and finally into a new individual.