Reproduction in plants

What do plants need to
survive?
 Water
 Air (oxygen and carbon dioxide)
 Sunlight
 Mineral salts
Fertilizers can be added to the soil to
increase the minerals available to
plants, more minerals help plants to
grow faster and stonger.

Plant structure
Bud
Leaf
Stem
Root
Flower

Reproduction in plants
 To reproduce plants have flowers
containing male and female reproductive
organs.
 The male part is called the stamen
 The female part is called the carpel or
pistil.

Pollen grains
receptacle
stalk
filament
sepal
Petal

POLLINATION
It is the transfer of pollen grains from the anthers to the
stigma
Pollinating agents
Insects Wind

Differences between insect &
wind pollinated flowers
Insect pollinated Wind pollinated
 Have large colored
petals with guide lines
 Have a scent
 Have a nectary on which
insects feed
 Have a sticky stigma for
pollen grains to stick on it
 The female and male
organs are enclosed in
the flower
 Pollen grains are larger
with spikes to hold on
insect body
 Have small green petals,
no guide lines
 Have no scent
 Have no nectary
 Have a feathery stigma to
catch the pollen in the air
 The female and male
organs are hanging
outside the flower
 Pollen grains are smaller
& light weight to be carried
by wind

POLLEN GRAINS AS SEEN UNDER THE MICROSCOPE
Can you tell which belongs to insect pollinated flowers / wind pollinated flowers?

FERTILISATION
It is the joining of male and female cells to produce a zygote.
Ovary Fruit
Ovule Seed

Seed structure
Radicle, grows
to be the root
Plumule, grows
to be the shoot
Seed
storage, food
that will be
used during
germination

Seed-fruit dispersal
 If a seed lands next to the parent plant and
germinates it will compete with the parent
plant for nutrients in the soil.
 Most plants developed methods to
scatter/disperse their seeds to ensure they
land further away from the original plant.
 There are 2 main methods of seed
dispersal:
 Wind dispersal
 Animal dispersal

Wind dispersal
Parachute e.g. dandelion Winged fruits e.g. Acer

Animal dispersal
Hooked fruits e.g. Burdock and others

Animal dispersal
 Other fruits are large coloured and
fleshy/juicy to attract animals to eat
them, swallowing the seeds at the
same time.
 The seeds have hard indigestible testa
that pass out with faeces in a new
area away from original plant.
 Example of such fruits: apple, acorn,
strawberries…etc.

Other ways of seed dispersal

Seed germination
 Once a seed falls onto a suitable surface
it starts to grow.
 Conditions needed for seed germination:
1. Suitable temperature
2. Oxygen
3. Water