Plant Adaptations for Success on Land

• Vascular tissue• Evolution of the seed that provides food and

protection• Many methods of seed dispersal• Evolution of pollen

Flowering Plant (Angiosperm) Reproduction

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What is the function of flowers?

• Reproduction– Attract Pollinators– Produce reproductive cells (pollen and ovules)– Form fruit and seeds once fertilized

Parts of a Flower

Parts of the Flower• Sepals= enclose flower bud

• Petals = attract pollinators

• Carpel= female reproductive organ– Stigma= receives pollen– Style= leads to ovary– Ovary= contains ovules (female

gametophyte)

Parts of a Flower (contd.)

• Stamen= male reproductive organ–Anther= produce pollen (male

gametophyte)–Filament= holds anther

•Pollen = each contains 2 cells- tube cell and a cell that makes two sperm

•formed by meiosis and contains 4 haploid cells•3 disintegrate•1 forms 7 cells by mitosis•1 becomes an ovum, and 1 becomes a cell with 2 nuclei (polar body)

Ovule Formation

Reproduction

1. Pollination2. Pollen tube carrying sperm grows toward ovule3. Double Fertilization

• Sperm + Egg= 2n cell (embryo and cotyledons)• Sperm + Polar body = 3n cell (endosperm)

4. Ovule becomes a seed5. Ovary becomes fruit

Reproduction Continued…

Seeds and Embryo Growth

•After fertilization cells divide and anchor embryo to parent

•Other cells divide to form the embryo

http://www.uic.edu/classes/bios/bios100/labs/2fert.jpg`

Continued…• Endosperm and embryo

surrounded by seed coat (dormant until germination)– Requires correct temp and

water– Enzymes digest endosperm

(nutrients)• Cotyledons develop

• Store food• Embryonic shoot develops (will

be stem and leaves) • Epicotyl (above the cotyledon) • Hypocotyl (below the cotyledon)

• Embryonic root develops (radicle)

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