adaptions for photo

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Transcript adaptions for photo

Adaptations for photosynthesis
Lesson objectives :1. Know how plants optimise their rate of photosynthesis
2. Recap the structure of plants
3. Adapt a plant yourselves
The leaf is the main site of photosynthesis.
light energy
carbon
dioxide
water
glucose
oxygen
chlorophyll
light
energy
chlorophyll
carbon
dioxide
water
oxygen
glucose
What are good features to have for
photosynthesis
Leaves
Obviously all plants have leaves, but what are they used for?
Leaves contain chloroplasts which is where photosynthesis
occurs. They also contain Stomata: this is where gases are
exchanged
Stomata
Stoma
Stomata are found on the underside of the leaf. Its here that
carbon dioxide is let in, and oxygen is let out. Water vapour is
also lost through the Stomata
So leaves need Sunlight to carry out photosynthesis.
Which leaf do you think will be able to get the most sunlight?
A
B
Plants that grow in dark shady environments often tend to
have very big and broad leaves. This helps them to catch
more sunlight
Controlling water losses
A lot of people make the mistake
and assume cacti don’t have leaves
They are wrong the spikes are the
cacti leaves.
Remember the stomata
The little holes
In Cacti they are located in the spikes.
Though there are not too many stomata,
in-case too much water is lost!!
Cacti spikes aren’t green though, this
means that there are no chloroplasts, so
no photosynthesis can occur there.
It only occurs in the stem
Roots
Root hairs
Fragile parts of
cells that grow
from the main
root
They massively
increase the
surface area for
absorption
There are many
different types of
root.
A plant's taproot is a straight
tapering root that grows vertically
down. It forms a centre from which
other roots sprout.
The taproot is why dandelions are
hard to uproot — the top is pulled,
but the long taproot stays in the
ground, and re-sprouts.
Cacti and other desert plants
have shallow roots that are useful
for catching a lot of falling rain
water.
Design your own plant
Include diagrams of what it looks like, and label what its
adaptations are for being good at photosynthesis.
Also include a description of the habitat it exists in and say
how it is adapted to that location.
E.g.
The Death Bottle Plant
Flower with
bright patches
to attract
insects
Cannon to fire
beetles and
seeds
Death
bottles
Nice big tap
root