19. When does fertilization in flower occur?
A. when the pollen grains swell
B. when the pollen tube grows larger
C. when the pollen grain falls on the stigma
D. When the sperm unites with the egg cell inside the ovule.
20. What is formed when fertilization has occurred in plants?
A. The fertilized ovule dies.
B. The fertilized ovule dries up and falls
C. The fertilized ovule becomes a seed.
D. The fertilized ovule becomes a flower.​