Cells and specialisation
All living things are made up of tiny, microscopic units which we call cells.
Animal cells
Animal cells are made up of many different elements:
| Structure | Function |
| Nucleus | Control centre of the cell. It contains the cell’s genetic information arranged in chromosomes. |
| Chromosomes | Threadlike structure found in the nucleus. Made of DNA which contains the genetic information of the cell. |
| Cytoplasm | Chemical reactions take place here. |
| Mitochondria | Site of cell respiration. Very abundant in cells that need a lot of energy (e.g. muscle cells). |
| Cell membrane | A selectively permeable boundary surrounding the cell which allows some substances to enter and leave the cell while preventing others. |
| Nuclear membrane | Surrounds nucleus. |
| Structure | Nucleus |
|---|---|
| Function | Control centre of the cell. It contains the cell’s genetic information arranged in chromosomes. |
| Structure | Chromosomes |
|---|---|
| Function | Threadlike structure found in the nucleus. Made of DNA which contains the genetic information of the cell. |
| Structure | Cytoplasm |
|---|---|
| Function | Chemical reactions take place here. |
| Structure | Mitochondria |
|---|---|
| Function | Site of cell respiration. Very abundant in cells that need a lot of energy (e.g. muscle cells). |
| Structure | Cell membrane |
|---|---|
| Function | A selectively permeable boundary surrounding the cell which allows some substances to enter and leave the cell while preventing others. |
| Structure | Nuclear membrane |
|---|---|
| Function | Surrounds nucleus. |
Plant cells
Plant cells contain all of the elements which make up animal cells, but they also include:
| Structure | Function |
| Cellulose cell wall | A rigid structure outside the cell membrane that provides support. |
| Large permanent vacuole | Contains cell sap and when full pushes the cell membrane against the cell wall, providing support. |
| Chloroplasts | Contain chlorophyll, a green pigment that traps light for photosynthesis. |
| Structure | Cellulose cell wall |
|---|---|
| Function | A rigid structure outside the cell membrane that provides support. |
| Structure | Large permanent vacuole |
|---|---|
| Function | Contains cell sap and when full pushes the cell membrane against the cell wall, providing support. |
| Structure | Chloroplasts |
|---|---|
| Function | Contain chlorophyll, a green pigment that traps light for photosynthesis. |
