Plants Structure and Function

Sexual Reproduction

Flowers

Function Contain the sexual

organs for the plant. Produces fruit,

which protects, nourishes and carries seeds.

Attracts insects for pollination.

Parts of the Flower

1. Sepals2. Petals3. Male Structures4. Female

Structures

Parts of the Flower

Sepals Outer covering of

the flower bud. Protects the

stamens and pistils when flower is in bud stage.

Modified leaves. Often green.

Parts of the Flower

Petals Modified leaves Brightly colored Protects stamen &

pistils. Attracts pollinating

insects. Carries pollen from

one flower to another.

Parts of the Flower

Petals of plants that have wind pollination: Small sepals/petal

or none at all.

Parts of the Flower (Stamen)

Male reproductive part = Stamen Filament

Stalk that supports anther

Anther Produces pollen =

sperm

Parts of the Flower (Pistil)

Female reproductive part = Pistil (3 parts) Stigma

Sticky top Holds the pollen grains

Style tube

Ovary Enlarged portion at base of

pistil. Produces ovules (eggs). If fertilized, develops into seeds.

Parts of the Flower

Pollination

• Wind or animals• Pollen reaches stigma• Fertilized Egg = Seed• Seed Coat: Protection• Seed Leaves• Developed from

embryo• Monocot: 1 leaf• Dicot: 2 leaves

• Endosperm: food supply for embryo

Pollination

• Fruit-Ovary Tissue• Seed develops here

• Examples:• Apple, watermelons,

cherries, vegetables, grains, nuts, tomatoes, cucumbers• Help with seed

dispersal so doesn’t compete with parent

Dispersal

Animals:•Tasty• Eat and then poop out

with fecal fertilizer.•Sticky• Ride away on• Ex. Burrs

Wind/Water•Parachute/Wings• Cottonwood

•Float• Coconuts

Dormancy

Until the right environment is available:•Temperature•Moisture•Oxygen•Light

Survive animal digestive tracts while softening the seed coat.

Germination

Steps:1.Seed coat cracks and embryonic root breaks through.2.A young shoot breaks through surface of soil.3.Leaves grow from shoot and begin to photosynthesize

Seedling