The cell is the unit from which all plants, animals and microorganisms are made. The cell is made up of a set of instructions called chromosomes (crow-mo-zomes; which tell the different parts of the cell what to make and do), factories (to make or use the molecules that the cell will need to survive) and some sort of membrane (mem-brain) or wall (to keep everything inside the cell safe from the outside).

In multicellular (Multi means more than two or many) living things, different cells can have special jobs. Because of this, animal cells have many different sizes and shapes.

There are two basic types of cell:

Prokaryotes
(pro-carry-oats; pro means before and karyon means nucleus), which include bacteria and


Eukaryotes
(you-carry-oats; eu means true and karyon still means nucleus) which include all other organisms

Prokaryotes are the simplest cells - they do not have a nucleus (new-clee-us) to protect their single chromosome, and their factories are very simple.

Eukaryotes do have a nucleus and these cells' factories are surrounded by their own membranes. These factories are called organelles (or-gan-els; or small organs) and each has a special function, needed by the cell to survive or perform its particular task.

Parents Please Note: The phonetic representations are meant as a guide to pronunciation only. Sound out each group of letters slowly, then faster and faster until they become a word.


Molecule (mol-e-q-ool) The smallest piece of a substance that still has its chemical properties. The simplest molecules have only one atom, but most molecules have more than one atom that are stuck together.
Atom (at-om) The smallest piece of a chemical which can not be broken down any further using chemical methods.

Nucleus (nucke-lee-us) A ball-like structure, separated from the rest of the cell by a special memebrane called the nuclear (new-cle-er) membrane. The nucleus holds the instructions or "chromosomes" of the cell and it is here that new chromosomes are made.