Question

What is the basis of classification of algae?

Answer 1

Algae are classified into three main classes - Chlorophyceae, Phaeophyceae, and Rhodophyceae. These divisions are based on the following factors:
(a) Major photosynthetic pigments present
(b) Form of stored food
(c) Cell wall composition
(d) Number of flagella and position of insertion

Class I - Chlorophyceae
Common name - Green algae
Major pigments - Chlorophylls a and b
Stored food - Starch
Cell wall composition - Cellulose
Flagella number and position - 2-8; equal and apical

Class II - Phaeophyceae
Common name- Brown algae
Major pigments - Chlorophylls a and c, and fucoxanthin
Stored food - Mannitol and laminarin
Cell wall composition - Cellulose and algin
Flagella number and position - 2; unequal and lateral

Class III - Rhodophyceae
Common name - Red algae
Major pigments - Chlorophylls a and b, and phycoerythrin
Stored food - Floridean starch
Cell wall - Cellulose, pectin, and polysulphate esters
Flagella number - Absent