specialised cells
- Created by: Kate Rontree
- Created on: 27-05-16 10:01
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- specialised cells
- Palisade leaf cells
- adapted for photo-synthesis
- packed with chloroplasts
- more of them are at the top of the cell so they are nearer the light.
- tall shape means a lot of the surface area is exposed down the side for absorbing CO2 from the air in the leaf.
- thin shape means that you can pack loads of them in at the top of the leaf.
- grouped together at the top of the leaf where most of the photo-synthesis happens.
- Guard cells
- adapted to open and close pores.
- special kidney shape which opens and closes the stomata in a leaf
- adapted to open and close pores.
- when the plant has lots of water the guard cells fill with it and go plump and turgid.
- makes the stomata open so gases can be exchanged for photo-synthesis.
- when the plant is short of water the guard cells lose water and become flaccid, making the stomata close
- thin outer walls and thickened inner walls making the opening and closing work.
- sensitive to light and close at night to save water.
- guard cells are therefore adapted to their function of allowing gas exchange and controlling water loss within a leaf
- Red blood cells
- adapted to carry oxygen.
- concave shape gives them a big surface area for absorbing oxygen
- helps them pass smoothly through capillaries to reach body cells.
- packed with haemoglobin - the pigment that absorbs oxygen.
- no nucleus- leaves even more room for haemoglobin.
- Sperm and Egg cells
- functions of an egg cell
- carry the female DNA
- to nourish the developing embryo in the early stages.
- egg cell contains huge food reserves to feed the embryo.
- when a sperm fuses with the egg, the eggs membrane instantly changes its structure to stop any more sperm getting in.
- makes sure the offspring ends up with the right amount of DNA.
- function of a sperm cell
- get the male DNA to the female DNA.
- has a long tail and a streamlined head to help it swim to the egg.
- has a lot of mitochondria in the cell to provide the energy needed.
- get the male DNA to the female DNA.
- sperm also carried enzymes in their heads to digest through the egg cell membrane.
- functions of an egg cell
- Palisade leaf cells
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