Transcript Revision (Respiration, Photosynthesis,Dispersal

Dandelion
The flower head matures into a spherical "clock" containing many
single-seeded fruits.
What enables the wind
dispersal of the dandelion
seed over long distances?
Dandelion Fruit
Dandelions seeds are often dispersed by
young children, who often blow on or kick it.
Dandelion Seed Dispersal
Rose
Rose hip
How is the rose hip dispersed?
• The hips are eaten by fruit-eating birds which
then disperse the seeds in their droppings.
Some birds also eat the seeds.
Recognize these plants?
How are they reproduced?
Recognize these plants?
How are they reproduced?
• Oxygen is consumed and carbon dioxide and
water are given off.
• Breakdown of glucose molecules
• Energy is liberated or released.
• Occurs at all times and is not dependent on
sunlight or chlorophyll.
• Oxygen is given off and carbon dioxide and
water are consumed.
• Energy is stored in glucose molecules
• Build up of glucose molecules
• Occurs only in cells containing chlorophyll and in
the presence of light.
Note: mainly from the leaves but also stems, flowers and roots.
• Water is taken up the plant from the roots to the leaves
(for photosynthesis and transpiration) - in xylem vessels
.
• Minerals dissolved in the water are taken up the plant to
the shoots and leaves - in xylem vessels.
• Food (the product of photosynthesis) is taken from the
leaves and moved up and down the plant to any part
which needs it (for growth or for storage) - in phloem
vessels.
• On the underside of the leaves are tiny holes called stomata which
allow the plant to breathe. When the water reaches the leaves it
evaporates and escapes through the stomata. As the water escapes,
more water is drawn up the xylem.
• But plants also need to have water evaporate from their leaves to cool
themselves down. So they need to strike a balance between water
gain and water loss.
• Plants control the amount of water lost through transpiration by
opening and closing their stomata. Two guard cells surrounding each
stoma can open and close it. The holes are opened to allow carbon
dioxide and oxygen to pass in and out, and are closed to reduce loss
of water.
For more interesting information and diagrams, go to:
http://www.bbc.co.uk/schools/gcsebitesize/biology/greenplantsasorganisms/1watertransportrev2.shtml