(a) Variation is seen among progeny formed by sexual reproduction because of:
(i) Involvement of two different individuals.
(ii) Creation of new combination of variants.
(i) A-pollen or pollen grain.
(ii) It reaches the stigma (B) by agents of pollination.
(iii) C (pollen tube) helps male gamete to reach the egg (ovule).
(iv) After fertilsation it converts into embryo.