Question

List the classes of algae.

Answer 1

1. Chlorophyceae - The members are commonly called ‘Green algae’. Most of the species are aquatic(Fresh water-Spirogyra, Marine -Ulva). A few are terrestrial(Trentipohlia). Variation in the shape of the chloroplast is found in members of algae.
2.  Phaeophyceae - The members of this class are called ‘Brown algae’. The majority of the forms are found in marine habitats. Pleurocladia is a freshwater form. The thallus is filamentous (Ectocarpus) frond-like (Dictyota)or maybe giant kelps (Laminaria and Macrocystis). The thallus is differentiated into leaf-like photosynthetic parts called fronds, a stalk-like structure called stipe, and a holdfast that attaches thallus to the substratum. 
3. Rhodophyceae - Members of this group include ‘Red algae’ and are mostly marine. The thallus is multicellular, macroscopic, and diverse in form. Porphyridium is the unicellular form. Filamentous (Goniotrichum) ribbon-like (Porphyra) are also present.