(a) How is apomixis different from parthenocarpy?
(b) Describe any two modes by which apomictic seeds can be produced. 3 mark
(a) Apomixis: In apomixis, seeds are produced without fertilization. It is a form of asexual reproduction that mimics sexual reproduction. In some species the diploid egg cell is formed without reduction division and develops into embryo without fertilization, e.g., some species of Asteraceae and grasses.
Parthenocarpy: In parthenocarpy, fruits are developed without fertilization, e.g., Banana. It can be induced through the application of growth hormones and such fruits are seedless.
(b) Two modes by which apomictic seeds can be produced:
(i) The diploid egg cell is formed without reduction division and develops into the embryo without fertilization.
(ii) Nucellar cells surrounding the embryo sac start dividing, protrude into the embryo sac and develop into the embryo. For example, Asteraceae and grasses. 3 mark