A pollen grain does not normally germinate until:
A. a zygote is formed.
B. cleavage has occurred.
C. pollination has occurred.
D. a diploid nucleus is formed.
In plant sexual reproduction, pollination (the transfer of pollen to the stigma of the pistil) occurs before the pollen grain germinates (grows) down to the ovary where the ovule (egg cell) is found. Then when the pollen grain reaches the ovule, fertilization occurs.