Which of the following best
describes the process of pollination? (A) The growth of a root and a
shoot from a seed after a period of dormancy. (B) The fusion of the male and
female gametes in a plant. (C) The transfer of pollen grains
from the male reproductive organs of a flower to the female reproductive organs. Or (D) the process of the
developing of male and female reproductive organs in flowering plants.
As you may have learned, many plant
species are capable of both asexual and sexual reproduction. Asexual reproduction, which in
plants is often referred to as vegetative propagation, does not involve the fusion
of gametes, or sex cells. During vegetative propagation,
parts of a single parent plant develop into new plants that are genetically
identical to the parent, referred to as clones. For example, strawberry plants
produce clones from special horizontal stems called offshoots.
In contrast, sexual reproduction
requires the fusion of male and female gametes. In flowering plants, these gametes
are located in the reproductive organs within flowers. The male organs are called stamens
and consist of a thin filament supporting an anther. The anthers produce pollen grains,
which contain the male gametes or sperm. The female organs are called
carpels or pistils. They consist of a stigma, a style,
and an ovary. Within the ovary are structures
called ovules, which surround the female gametes, called ova or ovum in the
For a sperm to reach an ovum,
pollen must make its way from the anther to the stigma. The transfer of pollen is
accomplished with the help of animals, including insects, bats, and hummingbirds, or
by wind. The cells of the stigma typically
produce a sticky substance that helps the pollen stay put once it is deposited. We call this transfer of pollen
from male organs to female organs pollination.
Therefore, the answer choice that
best describes pollination is (C): the transfer of pollen grains from the male
reproductive organs of a flower to the female reproductive organs.