Plant Structures & Reproduction
Plants have structures that aid in their reproduction. Some structures make it more likely that the plant will get
pollinated, while other structures aid in seed dispersal.
Methods of Pollination
Pollination is the first process to occur during plant fertilization. It occurs when pollen from an anther (the
male reproductive organ of a plant) is carried by wind, an insect, or some other carrier to the stigma (the
female reproductive organ of a plant).
Depending on how a plant is pollinated, it may have different structures to make pollination more
likely. Different methods of pollination and the structures that make these methods more likely are discussed
below.
 Insects — When an insect lands on a flower (often to feed
upon the flower's nectar), it may become coated in the
flower's pollen. When the insect lands on another flower, the
pollen grains it carried may be deposited on the plant's
female structure, resulting in pollination. Plants that are
pollinated by insects often have flowers that are brightly
colored or that produce an odor that attracts insects.
The bee in this picture picks up pollen grains as it feeds.
Image courtesy of USFWS

Other Animals — Other animals, such as bats and birds,
can aid in pollination in a way that is similar to insects. When a bat or bird feeds upon a flower, it can collect
pollen grains. When the bat or bird contacts another flower, the pollen grains may be deposited on the female
structure, resulting in pollination. Like plants that are pollinated by insects, plants that are pollinated by bats or
birds often have brightly colored flowers or produce a sweet odor.

Wind — Some flowers depend on wind to aid in pollination. In windpollinated species, the pollen grains are small and light so that they may be carried
through the air. Some of these pollen grains may be deposited on the female
structure of another flower, resulting in pollination. An example of a wind-pollinated
flower is ragweed.
This ragweed plant has small, light pollen grains that can easily be carried by the wind.
Methods of Seed Dispersal
After pollination has occurred, seeds that will grow into new plants are formed. Seeds can be dispersed, or
carried far from the parent plant, by wind, insects, birds, and other animals. Seeds usually have structures that
are suited to how they are dispersed.
Seed dispersal can occur in a few different ways. Some of these include:
 Animals — Animals can aid in seed dispersal in many different ways. Some plants have spiky, burr-like seeds
that stick to the fur of any animal walking by. After a while, the seeds will fall off of the fur and into the dirt in
some other location. A new plant can grow from this
seed. Other plants produce fruit that animals eat. As they
eat the fruit, the animals usually eat the seeds inside as
well. The thick, fleshy fruit protects the hard seeds as they
pass through the digestive tract of the animal. When the
animal passes the seeds out of its body as waste, a new
plant can grow in the new spot where they are
deposited. Still other plants produce nuts, such as acorns,
that some animals bury in the ground to store for the
winter. When acorns are buried, some remain buried and
eventually germinate.
Some plants have burrs that stick
to an animal's fur or berries that
an animal might eat. These are both structures that aid in seed dispersal.
 Wind — Some flowers depend upon wind to disperse their seeds. Seeds that
are dispersed by the wind are light and may have wing-like structures. This
allows the wind to carry the seeds over large distances.
Dandelion seeds have light, wispy material on the top so that they can easily be carried by the wind.
Animal Behavior & Reproduction
Animals often perform behaviors that increase their chances of successfully reproducing. These behaviors can
include courtship behaviors, as well as behaviors that help keep offspring safe once they are born.
Courtship Behaviors
A courtship behavior is the behavior of an adult of a species that is done to try to
attract a mate of the same species. Animals use courtship behaviors in order to ensure
that males and females of a species can recognize one another. Courtship behaviors
can include:
 the construction of special structures, such as the bowers created by male bowerbirds
Male bowerbirds create bowers with brightly colored blue objects in order to attract females.

courtship dances, such as those done by birds of paradise

the display of certain visual signals, such as the display of brightly colored
plumage performed by male peacocks
Male peacocks display their brightly colored plumage to attract females.

the release of special pheromones into the environment, such as those
released by ants when they are ready to mate

the display of certain audible signals, such as a bird song that is unique to a
certain species
Behaviors that Increase Offspring Survival
Offspring are the result of reproduction. Reproductive success is often judged not only by whether an animal
can produce offspring, but also by whether those offspring can survive to maturity. This is because the
purpose of reproduction is to pass one's genes on to the next generation. If an animal's offspring do not
survive to reproductive age, then they cannot pass their genes on to
offspring of their own.
Some animals perform behaviors to help increase the chances of at least
some of their offspring surviving to maturity. These behaviors can include:
 the production of many offspring, which helps ensure that at least a few
will survive in environments that are harsh or full of predators
 the construction of nests to provide warmth and protection for offspring
Many bird species build nests to provide
warmth and protection for their offspring.
 the formation of social groups,
which can help protect offspring
from predators
Female elephants usually travel in family groups. The adult elephants in these herds
position their offspring in the center of the herd so that they are better protected from
predators.