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Reproduction Involving Pollen in the air spread by the wind
Flowers can cause problems for people who
have allergies.
Many people have admired the
beautiful colors and smells of Other plants rely on animals to
flowers, and this is no accident. spread their pollen. These plants
The whole point of many flowers is are the ones with the beautiful
to be attractive to animals, colors and smells, designed to
generally insects, to help in attract insects and other animals to
reproduction. them. As the insects go from plant
to plant, they spread pollen from
Pollen, the male gametophyte, is one flower into the stigma of
found in many flowers. The another. The insect collects sweet
stigma, the female part of the nectar as a “reward” as it goes
flower, needs pollen in order for from flower to flower.
reproduction to occur.
Often plants will self-pollinate.
This means that the pollen of a
plant will fall onto the stigma of
that same plant. Other plants,
however, will cross-pollinate.
This means pollen from one plant
falls into the stigma of another
plant’s flower. Some flowers rely Figure 13 – In cross-pollination, plants
rely on insects or other animals to spread
on wind to spread their pollen. their pollen.
Plant Responses
Just because plants don’t usually
move on their own doesn’t mean
they don’t interact with their
environment. In fact, plants take
many actions depending on things
like sunlight, the season, and even
the presence of other plants.
Figure 12 – Pollen from some flowers is Plants, like animals, contain
spread by the wind. chemicals called hormones.
Hormones travel through the plant
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