Fertilization occurs when a sperm and an egg fuse.
Fertilization is complete when the sperm and egg nuclei fuse.
Fertilization occurs when a sperm and nuclei fuse.
Fertilization occurs when a sperm and nuclei what?

[A] fuse
[B] leave
[C] CO 2
[D] fusion
[E] emerge
[F] grow
[G] H 2 O
[H] procreate