In oogamy, fertilization involves
(a) A large non-motile female gamete and a small non-motile male gamete
(b) A large motile female gamete and a small non-motile male gamete
(c) A small non-motile female gamete and a large motile male gamete
(d) A large non-motile female gamete and a small motile male gamete
Ans. d
(7)