|Algae are diverse. Their main characteristics are:|
- their cells have membrane-bound nuclei (we call them eukaryotic)
- they contain chlorophyll and carry out photosynthesis.
Most algae are green. However, some algae contain other photosynthetic pigments which make them red.
They come in a number of forms:
- single celled - e.g. diatoms
- colonies e.g. Volvox
- filaments e.g. Spirogyra.
- macroscopic e.g. seaweeds.
The first three are microscopic. However, seaweeds grow up to 30 metres long and are not considered to be micro-organisms.