Life & Living
Reproduction
SEXUAL REPRODUCTION IN ANGIOSPERMS
SEED & FLOWERS
• Seeds are produced in the flowers of angiosperms.
• The sexual organs of angiosperms are situated in the flowers.
• Sepals – protect and enclose the other whorls while
the flower is developing.
• Stamens – male parts of a flower.
• Pistil – female parts of a flower.
• Stigma - nodule at the tip of the style that receives
pollen.
COMPONENTS OF A FLOWER
A flower contains both male and female
structures.
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• The stamen is the male structure.
• It is made up of the anther and the
filament.
• The anther contains pollen sacs which
produce pollen.
• The pollen contains the male sex cells.
• The filament is a long stalk that helps
to lift the anther to the top of the flower
so that the pollen can be released.
POLLINATION
Pollination and fertilisation are essential processes for flowers to
produce seeds.
• Pollination is the transfer of pollen between plants of the same
species, for fertilisation purposes.
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Factors that influence pollination:
• Plant species’ survival depends on pollination and so plants have
adapted to aid this process.
• Because plants can’t move around to find a mate, they must rely on
pollinators such as wind, water and animals, to disperse pollen.
POLLINATION
• Some flowers have unique adaptations to help the pollination process.
• For example, Carrion flowers (also known as stinking flowers or
corpse flowers), rely on flies to move pollen from one plant to
another.
• These flowers smell like rotting meat (carrion) and this smell attracts
the flies. For more information on this and other unusual plants go to
• Wind and water pollinated plants produce a lot of pollen
because so much of the pollen is simply washed or blown away.
• Some plants have stigmas that are situated outside of the
flower to allow the wind to easily catch the pollen.
• Flowers pollinated by insects are usually large and brightly
coloured to attract insects. These flowers also produce pollen
that is sticky enough to attach to insects.
• Some flowers also give off a scent to attract certain insects and
may even contain nectar to provide birds and mammals with a
food source and promoting pollination
Pollination by: Insects Birds Wind & Water
Fertilisation in plants
• Fertilisation occurs when the male & female sex cells fuse together.
• Each grain of pollen contains 2 male sex cells
• The ovule contains an embryo sac with 1 female sex cell, the egg
When pollinated, pollen sticks to the stigma
A thin tube grows out from the pollen grain
The pollen tube grows down the style to
the ovary & into the ovule
When the tube opens, male sex cells are
released & fuse with the egg cell
The fertilised egg is called a zygote
The other male sex cell fuses with 2 cells in
the embryo sac & develops into the
endosperm – starchy food that feeds the
developing seed.
Developing into a fruit.
Once fertilized, the flower loses sepals,
petals, stamen & upper parts of the pistil
The zygote starts to grow, the ovary swells
& develops into a fruit
The ovule develops into a seed
Animals & humans can eat the fruit and
seed is left behind on the ground
It can take a long time before the seed
starts to germinate.
Dispersal of seeds & fruit
Seeds & fruits can be dispersed by
any one of the following means:
• Wind
• Water Wind Water
• Animals & humans
• Self dispersal
Animals Humans
