Transcript Reproduction of A Flower

The Pollination Story
Diversity of Life
Grade 7
The Pollination Story
 The ovary of the flower is
where the seeds develop.
The Pollination Story
 As we know, the seeds contain an
embryo, which is the living baby plant
that has the potential to grow into a
new baby plant.
 Seeds start as ovules,
 tinypreseeds in the ovary.
The Pollination Story
 The ovary is
located at the
base of the
pistil in the
center of the
flower.
The Pollination Story
 Inside each
ovule is a
single, female
sex cell, the
egg.
The Pollination Story
 Some plants have one ovule in the
flower, such as a peach or cherry
flower.
Quic kTime™ and a
dec ompres sor
are needed to see this picture.
Quic kTime™ and a
dec ompres sor
are needed to see this pic ture.
 Other plants have hundreds of ovules
in the flower, such as a watermelon or
tomato flower.
Quic kTime™ and a
dec ompres sor
are needed to see this picture.
Qui ckTime™ and a
decompressor
are needed to see thi s pi cture.
The Pollination Story
 Before an ovule can develop into a
seed, the egg must be fertilized.
 An egg is fertilized when it joins with a
male sex cell, the sperm.
The Pollination Story
 The sperm cell is inside the pollen
grain. Pollen grains are produced by
the plant in the anthers at the tips of
the stamens.
The Pollination Story
 The process by which pollen gets from
the male anther to the female pistil is
called pollination.
QuickTime™ and a
decompressor
are needed to see this picture.
The Pollination Story
 Pollination is complete when a pollen
grain, carried by air or an animal, lands
on the sticky tip of the pistil, the stigma.
Quic kTime™ and a
dec ompres sor
are needed to see this picture.
The Pollination Story
 The pollen grain germinates and grows
a root-like structure that goes down the
length of the pistil. This is called the
pollen tube.
 The sperm cell from the pollen grain
travels down the pollen tube into the
ovule, and penetrates the membrane of
the egg cell.
The Pollination Story
 The contents of the two sex cells mix
together, forming a single, fertilized
cell.
 The fertilized cell is alive and has the
potential to develop into a new plant.
The Pollination Story
 Sexual reproduction happens when a
female sex cell (egg) and a male sex
cell (sperm) merge to form a single cell
with information from both the male
and the female.
The Pollination Story
QuickTime™ and a
decompressor
are needed to see this picture.
The Pollination Story
 Plants don’t get around much. In an
egg must be fertilized by pollen from a
different flower, how does that happen?
 How does the pollen get from one
flower to another?
The Pollination Story
 Please read Flowers to Seed
on page 40 of your science
resource book to discover the
answer.