pollination and fertilisation in flowers gcse

11
Reproduction in Flowering Plants

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A presentation about the pollination and fertilisation processes that take place in a flower.

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Page 1: Pollination and fertilisation in flowers GCSE

Reproduction in Flowering Plants

Page 2: Pollination and fertilisation in flowers GCSE

Flower• Sexual reproductive structure

• Produces egg and sperm

• Fertilization takes place inside the flower

Page 3: Pollination and fertilisation in flowers GCSE

Pistil*Stigma –top of the pistil,Sticky surface for pollen to

stick to*Style – connects the stigma to

the ovary*Ovary –contains ovules ( eggs)

Stamen*Anther – produces male

nuclei enclosed by pollen grains.

*Filament – holds the anther up

Female reproductive organ

Male reproductive organ

Page 4: Pollination and fertilisation in flowers GCSE

PollinationSelf-

pollination

• Pollen from the anther is transferred to the stigma

Page 5: Pollination and fertilisation in flowers GCSE

Cross Pollination• Pollen from the anther of one plant

is transferred to the the stigma of a different plant

Page 6: Pollination and fertilisation in flowers GCSE

• When a pollen grain lands on the stigma, it germinates and a pollen tube grows down through the style to an ovule (egg)

Page 7: Pollination and fertilisation in flowers GCSE

• The ovary and fertilized ovule develop and ripen.

*The ovule forms the seed and the ovary forms the fruit.

• A fruit is a ripened ovary

Page 8: Pollination and fertilisation in flowers GCSE

The plant embryo uses food stored in the cotyledon of the seed until it develops leaves

for photosynthesis

Page 9: Pollination and fertilisation in flowers GCSE

Wind/Insect Pollination

Page 10: Pollination and fertilisation in flowers GCSE

Feature Reasonsmall petals, often brown or dull green

no need to attract insects

no scent no need to attract insects

no nectar no need to attract insects

pollen produced in great quantities

because most does not reach another flower

pollen very light and smooth so it can be blown in the wind

anthers loosely attached and dangle out

to release pollen into thewind

stigma hangs outside the flower

to catch the drifting pollen

stigma feathery or net like to catch the drifting pollen

Wind Pollinated Flowers

Page 11: Pollination and fertilisation in flowers GCSE

Feature Reason

large, brightly coloured petals to attract insects

often sweetly scented to attract insects

usually contain nectar to attract insects

moderate quantity of pollen less wastage than with wind pollination

pollen often sticky or spiky to stick to insects

anthers firm and inside flower to brush against insects

stigma inside the flower so that the insect brushes against it

stigma has sticky coating pollen sticks to it

Insect Pollinated Flowers