How do seed plants grow & reproduce

20
HOW DO SEED PLANTS GROW & REPRODUCE ?

Transcript of How do seed plants grow & reproduce

HOW DO SEED PLANTS GROW & REPRODUCE?

WHAT CAN YOU SEE IN THIS PICTURE?

These are seeds

WHAT ARE

SEEDS?

Plants are just like us, they have babies & make new plants

-So, A seed is a baby plant

SEEDS

They are plants that are not fully formed

PARTS OF A SEED -A seed has 3 parts:

1 )Seed coat : A cover that protects the seed.

2 )Embryo: The baby plant.3 )Stored food.

Seed coat

Stored food

Embryo

WE CAN CLASSIFY THE SEEDS ACCORDING TO

Seed structure Where are seeds stored

-Water melons have flat small seeds.

-Mangos and peaches have one seed .

-Coconuts are giant seeds.

-Flowers that bear “make” seeds like: Apple trees

-Seeds found on the surface of the cones like: Pine trees..

A PINE TREE

A pine tree contains two types of cones:1) A Male cone.

2) A Female cone.

REPRODUCTION IN PINE TREES

Male cone Female cone

-Small cones.

-Present below the female cones on a conifer tree.

-Produce pollens “Yellow powder”

-Bigger cones.

-Present above the male cone in a conifer tree.

-Produce “make” the seeds when the pollens are carried by the wind and land on the female cone

THE FLOWER

-Most of the flowers have 2 parts:1) Male part Anther (Stamen) Filament

2) Female part Stigma (Pistil) Style Ovary Ovule

-The flower is the part of the plant which is responsible for reproduction .

THE FLOWER STRUCTURE

Stigma

Style AntherPollen tube

Filament

Ovule

PetalOvarySepal

POLLINATION - Now let’s see what happens inside a

flower

Pollination: it is the transfer of the pollens from the male part to the female part of the flower.

STEPS OF THE POLLINATION

1 )The petals have bright colors to attract insects to drink the nectar (sugary liquid) in the flowers.

2 )Pollen grains from the anther stick to the insects wings and gets carried to the stigma (Pollination)

3 )Tube “Pollen tube” grows down the style and enters the ovary

4)The pollen enters the egg in the ovary (seeds are made) (Fertilization)

5 )Then the ovary becomes a fruit and the petals fall.

A SEED’S LIFE Do you think a seed is alive or dead?

Well, A seed is alive but it waits for the conditions to be right to start to grow “germinate”.

THE CONDITIONS NEEDED FOR THE SEED TO GERMINATE:

- For the seed to germinate it needs:

Soil Heat Water

Warm temperature

GERMINATION PROCESS

A seed with a tiny embryo inside remains in the ground until conditions are right for the seed to germinate.

After the seed coat splits the embryo root begins to grow into the soil. Now the embryo can get water

Food in the seed feeds the embryo as the shoot (stem) grows upward the light.

The stem grows, leaves develop, and roots spread in the soil. Now the seedling can make its own food

SEEDS CAN BE PLANTED ALSO BY NATURE:

Nature can help in seed planting by