Plant Reproduction
Angiosperms (flowering plants)
 Plants
that protect their seeds within the body
of a fruit.
 Make up three fourths of all plants, including:
 Trees, shrubs, herbs,
grasses, water plants, etc…
Structure of a Flower
1. Pistil
2. Stigma
3. Style
4. Ovary
5. Stamen
6. Filament
7. Anther
8. Petal
9. Sepal
10.
Receptacle
11. Stem
Male Reproductive Structure
 The
stamen consists
of two parts: Anther
and Filament
 The anther is where
meiosis occurs to
produce haploid
pollen
 The filament is a
stalk that supports
the anther
Female Reproductive Structure
 The
pistil consists of
the stigma, style
and ovary
 The sticky stigma
receives the pollen
from the anther
 The pollen grows a
tube down
through the style
 Meiosis occurs in
the ovary to
produce haploid
ovules
Reproductive Structures
 Petals:
colourful
structures that
attract pollinators.
 Sepals:
surround
and protect the
flower bud.
Pollination
 Wind,
insects or
other animals
transfer pollen
from the anther of
one flower to the
stigma of another
 Flowers vary
depending on
pollination
mechanism
Pollination Vectors
Wind Pollination: Dull, scentless
flowers with reduced petals
The following sip nectar, get pollen on
coats, then transfer pollen from flower to
flower
Bees/Butterfly Pollination: Bright color,
nectaries, scent.
Bird Pollination: Nectaries, bright colors,
tube-like flowers
Moth Pollination: White petals, open at night
Fly Pollination:Rank odor, flesh colored
petals
Fertilization
 After
pollen lands on the stigma, a pollen
tube grows down through the style to
ovary
 Generative cell creates two sperm nuclei
 Double fertilization occurs:


one sperm fertilizes the egg
one sperm fertilizes the two polar nuclei
together
Result of Double Fertilization
 The
sperm nucleus and egg nucleus join
to form a 2n (diploid) embryo
 The
other sperm nucleus and the two
polar nuclei join to form a 3n (triploid)
endosperm. The endosperm is the food
supply for the embryo.
Seed and Fruit Development
 After
fertilization, the
petals and
sepals fall off
flower
 Ovary “ripens”
into a fruit
 The ovule
develops into a
seed
Seed Dispersal Mechanisms-
Allow plants to colonize new areas and
avoid shade of parent plant
Wind Dispersal - Flight
mechanisms, like parachutes,
wings, etc.
Ex. Dandelion, maples, birch
Animal Dispersal - Fleshy
fruits which animals eat, and
drop undigested seeds in
feces
or
burrs which stick to animals’
coats
Gravity Dispersal Heavy nuts fall to
ground and roll
ex. acorns
Water Dispersal - Plants
near water create floating
fruits
ex. coconuts