(a) In Amoeba, asexual reproduction occurs by fission (binary and multiple).In Amoeba, nucleus first divides into two daughter nuclei by mitosis and then body along with the cytoplasm constricts from the middle, which gradually deepens and eventually divides into two individual parts, each part has one nucleus. Thus, two daughter Amoebae develop from one. This is called binary fission. In multiple fission, nucleus repeatedly divides to from a large number of nuclei, which reach at the periphery. Later cytoplasm gathers around each nucleus to form a daughter, Amoeba. In this process, several individuals (equal to number of nuclei) develop from a single Amoeba.
(b) Sexual reproduction in plants takes place in the following steps:
(i) The male reproductive organ 'stamen' makes the male gametes.
(ii) The female reproductive organ 'carpel' makes the female gametes.
(iii) The male gametes fertilise the female gametes.
(iv) The fertilised ovules grow and become seeds.
(v) The seeds produce new plants under favourable conditions like presence of water, warmth, air, light. etc.
