The smallest of living organisms. Viruses are made up of a ball of protein that contains a small amount of the virus DNA. They can only reproduce after they have infected a host cell
A structure with a particular function which is made up of different tissues.
A bundle of neurones - it may be all sensory neurones, all motor neurones or a mixture of both
A list of often difficult or specialised words with their definitions.
Fungi (singular fungus) are either uni-cellular, as in yeasts, or multi-cellular, as in mushrooms, toadstools and moulds. Fungi have a nucleus, cytoplasm and a cell wall
Single-celled organism. Has a cell wall, cell membrane, cytoplasm. Its DNA is loosely-coiled in the cytoplasm and there is no distinct nucleus
Skin is the outer covering of vertebrate animals. It is the largest organ of the body and has many different functions. In other animals skin sometimes has mucous producing glands, the ability to change colour, thick fur, scales feathers or horns. In this e-source we´ll be looking at human skin.
Skin is very important as it covers and protects everything inside your body. Without skin, your bones, muscles and organs would be hanging out all over the place! Skin holds everything together. It also protects our bodies, helps keep our bodies at just the right temperature and, through nerve endings close to the surface of the skin, allows us to have the sense of touch.
However skin can become infected with bacteria, viruses and fungi, and can be irritated by chemicals or other substances it is in contact with.
Skin is also exposed to sunlight, and can suffer as a result.
Find out more about what your skin does for you, and how it works in this e-source.
There are a number of interactive features in this e-source: