Cells are the basic units of life. They are like tiny little factories producing everything organisms need. These cells form together to make tissues which are then built into organs.     

Both plants and animals contain cells but these two types of cells differ greatly. We will look at each of these types later, and see the differences and similarities between them and we will show what all the little structures within the cells (known as organelles).

Not only plants and animals contain cells. There are life forms which are entirely cellular – e.g. bacteria and fungi. These are incredibly small and, with rare exceptions, can only be seen with microscopes.   

Read about cell structure.