Question

Fertilisation is essential for production of seed, but in some angiosperms, seeds develop without fertilisation. 

(i) Give an example of an angiosperm that produces seeds without fertilisation. Name the process. 

(ii) Explain the two ways by which seeds develop without fertilisation.

Answer 1

(i) In the members of family Asteraceae, seeds develop without fertilisation. This process is called apomixis. 

(ii) Two ways by which seeds develop without fertilisation: 

(a) In some species, the diploid (2n) egg cell is formed without reduction division and develops into embryo without fertilisation.

(b) In many varieties of Citrus and Mango fruits some of the nucellar cells surrounding the embryo sac starts dividing, protrudes into the embryo sac and develops into embryos.