What is the basis of classification of algae?

(N/A) 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
$1$. $Chlorophyceae$ (Green algae): Major pigments are chlorophyll $a$ and $b$; stored food is starch; cell wall is made of cellulose; flagella are $2-8$,equal,and apical.
$2$. $Phaeophyceae$ (Brown algae): Major pigments are chlorophyll $a, c$ and fucoxanthin; stored food is mannitol and laminarin; cell wall is made of cellulose and algin; flagella are $2$,unequal,and lateral.
$3$. $Rhodophyceae$ (Red algae): Major pigments are chlorophyll $a, d$ and phycoerythrin; stored food is floridean starch; cell wall is made of cellulose,pectin,and polysulphate esters; flagella are absent.