Reproduction in Flowering Plants

The Parts of a Flower •  Most flowers have four

parts: •  sepals, •  petals, •  stamens, •  pistils. •  x

The parts of a flower •  Sepals protect the

bud until it opens. •  Petals attract

insects. •  Stamens (male)

make pollen. •  Pistils (female)

grow into fruits which contain the seeds.

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Stamen (male) •  Anther: pollen

grains grow in the anther.

•  When the grains are fully grown, the anther splits open.

•  Filament is the stalk-like structure that holds the anther.

Pistil (female) •  Stigma: captures the pollen •  Style: provides path to the

ovary •  Carpel (ovary): holds the eggs •  Ovules (eggs): develops into the

seed when fertilized!

Pollination •  Flowering plants use the

wind, insects, bats, birds and mammals to transfer pollen from the male (anther) part of the flower to the female (stigma) part of the flower.

Pollination •  A flower is pollinated

when a pollen grain lands on its stigma.

•  Each carpel/ovary grows into a fruit which contains the seeds.

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Fertilization •  Pollen grains contain a

“tube nucleus” which forms a tube that grows down the style so that the sperm can reach an ovule.

•  Fertilized ovules develop into seeds.

•  The ovary/carpel enlarges to form the flesh of the fruit and to protect the ovary.

According to botanists (those who study plants) a fruit is the part of the plant that develops from a flower. It's also the section of the plant that contains the seeds. The other parts of plants are considered vegetables. These include the stems, leaves and roots. The following are technically fruits: avocado, beans, peapods, cucumbers, grains, nuts, olives, peppers, pumpkin, squash, sunflower seeds and tomatoes. Vegetables include celery (stem), lettuce (leaves), cauliflower and broccoli (buds), and beets, carrots and potatoes (roots).

Wind pollination •  Some flowers, such as

grasses, do not have brightly coloured petals and nectar to attract insects.

•  They do have stamens and pistils.

•  These flowers are pollinated by the wind.

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Seed dispersal Seeds are dispersed

in many different ways:

•  Wind •  Explosion •  Water •  Animals •  Birds •  Scatter/Gravity

How birds and animals help seed

dispersal •  Some seeds are

hidden in the ground as a winter store.

•  Some fruits have hooks (burs) on them and cling to fur or clothes.

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How birds and animals help seed dispersal

•  Birds and animals

eat the fruits and excrete the seeds away from the parent plant.

Asexual Reproduction •  Single parent •  Does not require

the union of male and female sex cells

•  Good because it is convenient!

•  Bad because flowers/fruits can’t be improved!

Examples Include: •  Runners

(strawberries) •  Daughter bulbs

(tulips) •  Cuttings (growing

new plants from twigs or branches)

Sexual Reproduction •  Leads to more diversity! (Advantage) •  Must have a sperm (male) and egg

(female) cell. •  If a flower has both male and female parts

it is called a perfect flower.