(a) Exine of pollen grains is made up of sporopollenin
(b) Pollen grains of many species cause severe allergies
(C) Stored pollen in liquid nitrogen can be used in the crop breeding programmes
(d) Tapetum helps in the dehiscence of anther
[NEET 2016, Phase 1]
Correct Option (d)
Reason : Tapetum is the inner layer of microsporangium (anther) which provides nourishment to developing pollen grain after meiotic cell division.