What is the basic of classification of algae ?

Explanation

Earlier the algae were classified on the basis of single visible character, viz., colour of algae thalli (e.g., green algae, brown algae, red algae, etc.). Now they are classified on the basis of more than one characters, i.e., (i) colour of thalli , (ii) their storage products , (iii) cell wall chemistry , (iv) flagellation and cellular organizations.