What is the basis of classification of algae?

Explanation

Algae are chlorophyll containing thallophytes and their relatives. These are characterised by presence of nonjacketed gametangia. All the cells are fertile in these gametangia and there is absence of embryo stage. F.E. Fritsch in 1935 divided algae into all classes on the basis of following featurs `:`
(i) Number and mode of attachement of flagella in motile cell.
(ii) Thallus structure, (iii) Chemical nature of pigments, (iv) Reserve food material, (v) Methods of reproduction, and (vi) Variations in the life cycles.