Biology Work

Biology
All animals and plants are made of cells. Animal cells and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Note that cells may be specialised to carry out a particular function.
Dissolved substances pass into and out of cells by diffusion. Water passes into and out of cells by osmosis.
Animal and plant cells
Function of cells which animal and plant cells have in common
part | function |
nucleus | contains genetic material, which controls the activities of the cell |
cytoplasm | most chemical processes take place here, controlled by enzymes |
cell membrane | controls the movement of substances into and out of the cell |
mitochondria | most energy is released by respiration here |
ribosomes | protein synthesis happens here |
Plant cells also have extra parts:
Extra parts of plant cells
part | function |
cell wall | strengthens the cell |
chloroplasts | contain chlorophyll, which absorbs light energy for photosynthesis |
permanent vacuole | filled with cell sap to help keep the cell turgid |
Make sure you can label diagrams of animal and plant cells, like these:

Generalised animal and plant cell
Specialised cells
Cells may be specialised for a particular function. Their structure will allow them to carry this function out. Here are some examples:
Examples of the functions of cells
Cell | Function | Adaption |
Leaf cell | Absorbs light energy for photosynthesis | Packed with chloroplasts. Regular shaped, closely packed cells form a continuous layer for efficient absorption of sunlight. |
Root hair cell | Absorbs water and mineral ions from the soil | Long 'finger-like' process with very thin wall, which gives a large surface area. |
Sperm cell | Fertilises an egg cell - female gamete | The head contains genetic information and an enzyme to help penetrate the egg cell... [continues]

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