The cell wall of algae is made up of . . . . . . .

Green algae contain:

Match the following classes of algae with their characteristic colours:
$A.$ Cyanophyceae $a.$ Green colour
$B.$ Chlorophyceae $b.$ Blue-green colour
$C.$ Phaeophyceae $c.$ Red colour
$D.$ Rhodophyceae $d.$ Brown colour

Spermatia are the male gametes of ........

The absence of chlorophyll in the lowermost cells of $Ulothrix$ indicates:

Which one of the following shows similarity with blue-green algae on the basis of photosynthetic pigments?