Seed ReproductionChapter 9 Notes

Seed Reproduction

• Plants need to reproduce to carry on their species.

• Plants reproduce due to the movement of pollen and seeds.

Pollen

• Pollen contains the males sperm. It is known as a gametophyte. When the pollen reaches female plant parts, fertilization occurs.

• After fertilization, seeds form. These seeds are the plants offspring.

Seeds– The seed contains an embryo, stored food (in the

cotyledon), and a protective coat.

Because the seed is so well protected and fed, the plant grown from it will grow faster compared to

spores (seedless reproduction).

Why would the seed want stored food and

a protective coat?

Two Types of Seed Reproducers

• Angiosperms

What’s the difference?

• Gymnosperms

Angiosperm

• Angiosperms produce flowers which are used for sexual reproduction.

Par

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Anther

Filament

Sepals

Stigma

Pistil

Ovary

Stamen

Style

Angiosperm– The stamen is the male reproductive organ.

– The pistil, the female reproductive organ, contains the ovary at its base.

Angiosperm

– The appearance of a plant’s flower can give clues about how the plant is pollinated.

– After pollination and fertilization, a zygote forms and grows into the plant embryo.

– Parts of the ovule develop into the seed coat and store food for the embryo.

Angiosperm• Some seeds store food in cotyledons.• Other seeds store food in endosperm tissue

Where are seeds found?

• THE FRUIT. So…fruit is like the plant’s baby.

Fact: Fruits have seeds. Vegetables

do not. A true vegetable is usually a root. (potato, carrots,

onion)

A. Pollination happens when pollen grains from the anthers land on the sticky stigma of a pistil. B. The pollen tube

grows from the pollen grain down through the style and into the ovary at the ovule.

C. The sperm travels down and fertilizes the egg. The zygote develops.

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Gymnosperm

• Gymnosperms develop seeds in cones.

Gymnosperm– A pine tree or shrub is a

sporophyte plant that produces male and female cones.

– A female cone has two ovules which produce eggs.

– Male cones produce and release pollen.

Gymnosperm– When pollen blows into a female cone, fertilization and

seed formation can occur.

– Seed released by a female cone can take two or three years.

http://www.youtube.com/watch?v=D9byVQxvMXs&feature=related

Seed Dispersal

• Seeds are dispersed by wind, gravity, animals, and water. Some seeds have trapped air which helps them float.

– Germination occurs when the seed coat swells and breaks open.

– Environmental conditions affect germination.