Biology Unit 2a - Specialised Cells: Higher
- Created by: Clover
- Created on: 24-02-16 19:09
View mindmap
- Specialised Cells: Higher
- Palisade Leaf Cells
- They are adapted for PHOTOSYNTHESIS.
- Packed with CHLOROPLASTS for PHOTOSYNTHESIS. More of them are crammed at the top of the cell - so they're nearer the light.
- TALL shape means a lot of SURFACE AREA 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 a leaf.
- Palisade leaf cells are grouped together at the top of the leaf where most of the PHOTOSYNTHESIS happens.
- Guard Cells
- They are adapted to OPEN AND CLOSE PORES.
- Special kidney shape which OPENS and CLOSES the STOMATA (pores) in a leaf.
- When the plant has LOTS of water the guard cells fill with it and go plump and TURGID. This makes the stomata OPEN so GASES can be exchanged for PHOTOSYNTHESIS.
- When the plant is SHORT of water, the guard cells lose water and become FLACCID, making the stomata CLOSE. This helps stop too much water vapour ESCAPING.
- THIN outer walls and THINKENED inner walls make the opening and closing work.
- They're also SENSITIVE TO LIGHT and CLOSE AT NIGHT to save water without losing out on photosynthesis..
- Guard cells are therefore adapted to their function of allowing GAS EXCHANGE and CONTROLLING WATER LOSS within a LEAF.
- Red Blood Cells
- CONCAVE shape gives a big SURFACE AREA for absorbing OXYGEN. It also helps them pass SMOOTHLY through CAPILLARIES to reach body cells.
- Palisade Leaf Cells
Comments
No comments have yet been made