CELLS are building blocks of life. These all work together doing the same function. Some examples are blood cells and sperm cells.

TISSUES are made of all the cells working together. Some examples of these are the muscle tissue and the brain tissue.

ORGANS are made of all the tissues working together. Some organ examples are the heart and the brain.

ORGAN SYSTEMS are all the organs working together. Some examples of these are the circulatory system and the respiratory system.​To be deemed living an organism must do all of the seven life processes​​The Seven life Processes are (MRS GREN):​MovementRespirationSensitivityGrowthReproductionExcretionNutrition

The cell is made up of many different parts.Animal cells contain the Cell membrane, Nucleus, cytoplasm, Mitochondria and Lysosomes. These each carry out a function; the cell membrane keeps out anything unwanted, the nucleus stores all the cell information, the cytoplasm keeps everything in the cell 'cushioned' in case anything should happen to it, the lysosomes contain digestive enzymes and the mitochondria gives out the food the cell needs to respire.The plant cell contains more organelles than the animal cells, containing the cell membrane, nucleus, cytoplasm, mitochondria, chloroplasts, cell wall and vacuole. the chloroplasts carry out photosynthesis - the function that turns water and carbon dioxide into energy -, the vacuole stores water and the cell wall keeps the shape of the cell.There are more parts to these cells, but this is all you need to know for GCSE.

Animal and Plant CellsPlants and animals have cells too though plant cells are different from animals.The diagram on the left shows the different parts on the cells labeled. As you can see, the plant cell has all the parts of an animal cell plus more.

Part Definitions (from top to bottom):Cell Membrane- Takes control of the substances going in and out of the cell.Cytoplasm- Where chemical reactions take place.Nucleus- Controls the cell.​Mitochondria - where respiration happensThe following are only in plant cells:Chloroplast- Where photosynthesis occurs. It contains a substance called chlorophyll.Vacuole- Keeps the cell in place by a liquid called cell sap.Cell wall- Supports the cell. Made from a substance called cellulose. ​cells are so small you need a light microscope

​Microscopesa light microscope uses a series of lenses to magnify an image​stains on a slide like iodine makes it easier to see​​​