Download Plant Anatomy & Physiology

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.
2.
3.
4.
Sepals
Petals
Male Structures
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