reproduction lesson 5a (pollination and fertilisation)

Questions to think about…

What are the parts of a flower?

How do flowering plants

reproduce?

What are the functions of each part of a flower?

Pollination

• Pollination is the transfer of pollen grains from the anther to the stigma of a flower.o The pollen grains can be transferred within

the same flower.

stigma pollen grains from anther

Pollination

• Pollination is the transfer of pollen grains from the anther to the stigma of a flower.o The pollen grains can also be transferred from

one flower to another.

Pollination Video

http://www.youtube.com/watch?v=RuYrFwDuYn0

Fertilisation

• When a pollen grain lands on the surface of a stigma, it produces a tube.

• The inside of the tip of the tube contains the male cells of the flower.

• These tubes grow down the style to reach the ovules in the ovary.

• Inside each ovule is an egg cell.

pollen grainsstigma

pollen tubes style

ovary

ovuleegg cell

Fertilisation

• When a pollen tube reaches the ovule, the female egg cell and male cell combine.

• This process is called fertilisation.

yellow pollen grains on a flower

From flower to fruit

• Sexual reproduction involves a male and a female.

• The process of producing new plants from seeds involves both male and female cells.

• Thus, sexual reproduction takes place in plants.

From flower to fruit

After fertilisation, most of the flower parts wither and drop off

except for the ovary.

Inside the ovary, the ovules begin to

develop into seeds.

The ovary then grows bigger until it becomes

a fruit.

seeds develop inside the fruit, fruit grows bigger

petals drop off

ovary begins to swell

petals wither

flower (after fertilisation)

Pair Work

• Pupils to work in pairs to complete Plant Plays “Pollination and Fertilisation” Worksheet

What have we learnt?

• Processes of pollination and fertilisation.

What have we learnt?Pollination

•Pollination is the transfer of pollen grains from the ripe anther to the stigma. This is done either by wind or by animals. If pollination happens within the same flower or between different flowers on the same plant, it is called self-pollination; if it happens between flowers from different plants of the same species, it is called cross-pollination.

What have we learnt?Fertilisation

•Once a pollen grain lands on a stigma, it grows a tube into the stigma, down the style to reach an ovule in the ovary. The tip of the pollen tube breaks open to release a nucleus which fuses with the nucleus of the egg cell. Fertilisation has taken place. The ovule develops into a seed and the ovary develops into a fruit.