2. LO: I can demonstrate a plant life cycle
• We are going to plant some seeds and watch
them grow over the next few weeks.
• What do plants need in order to grow from
seeds?
3. • What is the life cycle of a
plant? - BBC Bitesize
13. Asexual Reproduction
Some plants use sexual reproduction to
make seeds, which grow to make new
plants.
These plants need pollen (containing the
male gamete or sex cell) from one flower
to fuse with the ovule (the female
gamete) of another flower, which makes a
seed.
However, some plants use asexual
reproduction to make new plants.
Unlike sexual reproduction, asexual
reproduction only needs one parent plant
to make new plants.
Because there is only one parent plant,
there is no fusion of gametes, and no
mixing of genetic information. The new
plants are identical to the parent plant.
They are clones.
14. Plants That Use Asexual Reproduction
Daffodil bulbs store
energy underground.
Once the daffodil plant
has died back, the bulb
develops side shoots that
will grow into new
daffodils for next year.
Potato plants grow tubers
underground during the
spring and summer. These
tubers will grow into new
plants the following spring
if they are left undisturbed.
Some plants develop bulbs or tubers
underground. These bulbs or tubers will develop
into new plants for the following year. The new
plants will be genetically identical to the parent
plant.
Daffodils and potatoes are examples of plants
that reproduce this way.
15. Plants That Use Asexual Reproduction
Strawberry
plants send out
runners with
small plantlets
on. These will
each grow into
a new
strawberry
plant.
Spider plants send out
branches with baby
plantlets on. Each
plantlet will grow into a
new plant.
Other plants produce side branches or runners
with new plantlets on. The roots of each plantlet
grow down into the soil, and the plantlets will grow
to form new plants identical to the parent.
Spider plants and strawberries are examples of
plants that reproduce this way.
16. Advantages and Disadvantages
There are advantages
and disadvantages to
plants using sexual or
asexual reproduction.
Have a look at the
statements on your
Advantages and
Disadvantages Activity
Sheet. Can you match
each statement to show
whether it is an
advantage or
disadvantage of each
type of reproduction?
17. Making New Plants
You are going to work with
a partner to try to make
new plants from one parent
plant. If you are successful,
each plant that grows will
be a clone of the parent
plant! This means it will be
genetically identical to the
parent plant.
Follow the instructions on
your Taking Cuttings
Activity Sheet to try to
make new geranium plants.
Complete the activity sheet
with your explanation of
how you will make new
plants.
18. What’s New?
Tell your partner
three new things
you have learnt
today.
Include two things
about asexual
reproduction and
one thing about
taking plant
cuttings.
19. LO: Types of seed dispersal
When the pollen reaches
another flower, it travels to
the ovary where it fertilises
the egg cells to make seeds.
This process is called
fertilisation. These seeds
are scattered by animals or
the wind. This process is
called dispersal.
20. Sycamore ‘helicopters’ and
dandelion ‘clocks’ both have
fruits which have adapted to
use the wind to carry the
seeds away when the seeds
are ready.
Wind
21. Some plants have pods
full of seeds which will
burst, showering the
ground with seeds, like
the Himalayan Balsam
seed.
Peas are another
example of a plant
bursting open to disperse
its seeds.
Bursting
22. Some plants rely on being
shaken to disperse their
seeds. When poppies have
produced their seeds and
have finished flowering all
that is left is a long stem
with a dried seed pod.
These pods have small
holes at the top and rely on
wind to shake them to
scatter the seeds. This
method doesn’t send the
seeds very far. Yucca
Campestris seeds also need
to be shaken.
Shakers
Poppy
seeds
23. Some plants rely on water to
disperse their fruits. These
will either grow on the water
or by the side of water.
Water lilies live on the water
so they use the water to
disperse their seeds. They
make very light seeds which
will float away on the water
for a while, then sink to the
bottom of a pond to grow a
new lily.
Water
24. Palm tree seeds are very light which helps
them float and grow another palm tree
elsewhere. Palm trees that grow by the
oceans drop their seeds which can be swept
great distances by the ocean’s currents.
Coconuts are well known travellers.
Willow and silver birch
trees often grow near water.
Their seeds are very light
which enables them to float
away on water (the silver
birch seed is also fluffy
which helps them to be
dispersed by the wind too).
25. Some plants such as
cockleburs have developed
to grow tiny hooks on their
fruits which hook on to
animals (or people) that
pass by the plant.
Eventually they will drop off
on to the ground.
Catchin
g a Ride
26. Some plants make tasty
fruits. This is to encourage
animals (and people!) to eat
the fruits. The seeds then
pass through the animal
unharmed and out the other
end with a ready supply of
fertiliser (not tasty in the
slightest… quite the
opposite). This method
ensures the seed is given
nutrients to help it grow.
Seeds
as Food
What types of fruits can you
think of that are eaten by
animals and people with
seeds inside?
27. Some fruits, such as horse
chestnuts, have a casing
round them which cracks
open when it hits the
ground. The fruit inside then
rolls away from the tree.
You can tell which horse
chestnuts in the trees are
ripe because their casings
have already begun to split
open before they drop.
Drop
and
Roll!
28. Why do plants disperse their seeds?
List the ways in which the seeds are
dispersed.
Plenary