Seed formation is initiated by changes in environmental
|Figure 3.1 The female reproductive organ is called the carpel. The carpel
is made up of a stigma and ovary connected by the style. The male
reproductive organ is a stamen. The stamen consists of anthers, which
contain the pollen grains, suspended on a thin filament. Pollen grains
land on the stigma, which has a sticky surface, and develop a pollen
tube that grows downward through the style until it reaches the ovary.
The ovary contains ovules (eggs), and the pollen grains produce sperm.
The sperm cells travel down the pollen tube and fertilize the ovules. The
ovary grows into a fruit and the other parts wither away.
such as the difference in daytime and nighttime
temperatures and the relative number of hours of daylight versus
darkness, and also by the production of plant hormones.
The process begins with the development of flower buds. Pollination
occurs after the flower blooms and involves the deposition
of the male pollen onto the female stigma. Pollination is
followed by fertilization, which is required to produce viable
Fertilization occurs when sperm cells from the pollen
grain reach the ovules in the ovary and combine with an egg.
The fertilized egg develops into a seed that contains an embryonic
plant in a dormant state. Reproductive structures are
illustrated in Figure 3.1.