- Different types of cells carry out specific functions and when all cells combine their functions, they can share out the processes of life.
- Each cell is dependent on the other and all of them function collaboratively to support the diverse processes in an organism
- When cells are specialised they carry particular job and develop a distinct shape. The changes in shape enable the cell to carry out its special function.
1. Red blood cell (erythrocytes)
- Its function is to transport oxygen from lungs to body tissues and carbon dioxide from body tissue to the lungs.
- Lacks a nucleus to increases surface area for absorption of oxygen.
- Their bi-concave shape and flexibility allow them to pass along small capillaries.
- Contains haemoglobin (red pigment) which carries oxygen needed for cell respiration to produce energy.
2. Muscle cell
- It is responsible for contraction when stimulated by a nerve so that movement occurs.
- They are long and thin and have the ability to change their shape when they contract.
- Have large numbers of mitochondria to provide energy for muscle contraction.
3. Palisade cell
- Its function is to make food by photosynthesis.
- Packed with chloroplasts that contain chlorophyll for absorption of light.
- They are columnar and closely packed to increase surface area for absorption of sunlight and carbon dioxide.
4. Root hair cell
- Responsible for absorption of water and salts from the soil.
- Have thin cell walls to allow water and nutrients to pass easily from the soil
- They are numerous to increase surface area for absorption of water and mineral salts as they are in close contact with the soil.
- The hair like projection on each cell penetrates between the soil particles and offers a large absorbing surface area.
- Large vacuole facilitates water absorption and storage.