|Simple Green Algae|
|Enteromorpha, Ulva comprise of sheets one to two layers thick.
The Chaetomorpha species are simple and unbranched filaments of cells that are placed end to end.
In the Cladophora the filaments are branched.
These seaweeds are made up of continuous, branching tubes with numerous nuclei and few or no cross-walls, even though the plant may be quite complex in structure. The chloroplasts in their tubes can migrate up and down in the tubes making the best of the light intensity. They migrate to the surface when the light is very dull and away from the surface when light reaches destructive excessiveness. Many species contain chemicals that deter herbivores.
|Codiums and Valonia|
The Codiums have thick spongy branches that comprise of interwoven tubes that end in utricles (specialized swellings) which cover the surface. When Codium is squeezed the utricles separate. In Pseudocodium on the other hand the sells adhere to one another. Valonia consists of interconnected baloon-like sacs.