Seeds
Fertilization
Sexual reproduction is the result of
the male and female gametophytic
cells fusing to form a zygote.
Pollen germinates of the female
stigma and the male gametes move
down the pollen tube through the
female style.
The pollen tube enters the embryo
sac through the micropyle in the
ovule to release the male gametes
(see Chapter 4).
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Petals
Fertilization
The photomicrograph to the right
is an unopen female flower of wild
cucumber.
Stigma
Style
It has an inferior ovary that
forms under the petals.
Ovule
Ovary
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Fertilization
Embryo sac
Sexual reproduction is the result
of
the
male
and
female
gametophytic cells fusing to form
a zygote.
Integuments
Micropyle
Funiculus
Illustrated here is one example
of an angiosperm ovule.
It contains three antipodal cells,
two polar nuclei, two synergids,
and an egg cell.
Embryo sac
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Fertilization
Female flower sexual parts.
Embryo sac
Integuments
Micropyle
Funiculus
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Fertilization
Male gametes move along the
pollen tube. The tube nucleus
guides the pollen tube into
the female embryo sac.
The generative nuclei are the
male gametes that will fuse
with the female nuclei in the
embryo sac.
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Fertilization
The pollen tube enters through the micropyle to deposit the sperm cells.
Female
egg cells
Pollen
tube
Embryo
sac
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Sperm cells
being released
from the pollen
tube.
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Fertilization
Angiosperms undergo double fertilization where one sperm generative
nucleus fuses with the egg nucleus to form the zygote and the other
generative nucleus fuses with two polar nuclei to form the triploid endosperm.
Embryo sac
Fertilized
endosperm
Fertilized
zygote
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