In angiosperms , the pollen grain germinates to produce pollen tube that carries two gametes what is the purpose of carrying two gametes when single gamete can fertilize the egg ?

Explanation

(i) The second gamete fuses with diploid secondary nucleus in the embryo sac of the ovule .
(ii) This forms the triploid endosperm nucleus which develops into the endosperm tissue and gives nourishment to the develooping embryo.
(iii) When the ovule forms the seed after fertillization , the endosperm serves to give nourishment to the embryo during germination until the set of foliage leaves are formed by the seedling or baby plant.