Micro-organisms

Micro-organisms (also known as microbes) are life-forms that cannot be seen by the naked eye. They include archaea, bacteria, protists and some kinds of algae and fungi...

Algae

Algae are simple, plant-like protists. An alga has no proper roots, stem or leaves, although it may have a stem-like part and a leaf-like blade. It absorbs water and nutrients...

Bacteria

The commonest living things are bacteria. They are too small to see without a microscope. Bacteria are all around us in their billions. They are found in every habitat on Earth...

Protists

Like bacteria, protists are microscopic, single-celled organisms. But unlike bacteria, each protist has its genetic material (DNA) wrapped inside a bag-like membrane to form the...

Moulds and yeasts

Moulds and yeasts are two groups of micro-organisms that belong to the fungi kingdom. Found in dark, damp environments, moulds grow thin, pale threads called hyphae forming a...

Viruses

The smallest living things are viruses. They are “alive” only because they can produce more of their kind if they invade another living thing. Viruses cannot reproduce on their...

Micro-organisms A-Z