Specialised Cells

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  • Created by: I
  • Created on: 05-04-14 11:47

Palisade Cells

(http://year12bio.wikispaces.com/file/view/palisade%2520cell.jpg/73441315/372x277/palisade%2520cell.jpg)

  • Packed wiht chloroplasts for photosynthesis. Crammed at the top of the leaf so nearer sunlight
  • Tall shape means large surface area exposed down the side for absorbing CO2
  • Thin shape => pack loads of them on top of the leaf where most of photosynthesis happens.
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Guard Cells

  • Kidney shape ehich opens and closes th stomata in a leaf
  • When plants have lots of water the guard cell fillwithitand go plump,turgid. Makes the stomata open s gase exchange can take palce for photsynthesis
  • When the plant is short of water guard cells lose water and become flacid making the stomata close. Helps stop too much water escaping.
  • Thin outer walls and thickened inner walls make the openng and closing work.
  • Sensitive to light, close at nihgt to save water without losing out on on photosynthesis.
  • Adapted to their function of allowing gas exchange and contollling water loss wihtin a leaf.
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Red Blood Cells

  • Concave shape gives a big surface area for absorbing oxygen, helps them pass smoothly through cappilleries to reach body cells.
  • Packed with haemaglobin- pigment that absorbs oxygen
  • No nucleus, leaves more space for haemaglobin
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Sperm and Egg Cells

Egg Cell

  • Carry female DNA
  • Nourish the developing embryo
  • Contains huge food resoures to feed the embryo

Sperm Cell

  • Get the maleDNA to the female DNA
  • Long tail and streamlined head hlp it swim to the egg
  • Middle secttion contains lots of mitochondria in the cell to provide the energy needed
  • Carry enzymes (ancrosome) in their heads to digest through the cell membrane.

Sperm and eggs very imotant for reproduction

When sperm fuses with egg, the egg's membrane instantly changes its structure to stop anymore sprem getting in. Makes sure offspring end up with correct amount of DNA. 

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Fat Cell

  • Help animals survive when food is in short supply
  • If you eat more than your body needs makes store in fat cells
  • Few mitochondria as don't need much energy
  • Small amount of cytoplams and larg amount of fat
  • Can expand 1000 times bigger -fills its capabillity
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Root Hair Cell

  • Found close to the tips of growing roots
  • Root Hairs increses surface area
  • Close to xylem tissue so water and minerals transported around plant quicker
  • Xylem tissue carries water and minerals ions up into the rest of plant
  • Large vacuole speeds up the movement of water from the soil into the cell by osmosis
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jim carts

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too many spelling mistakes

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