An example of an agarophyte is

Which of the following statements are applicable to brown algae?
$(I)$ They contain pigments like chlorophyll $a$,chlorophyll $c$,carotenoids,and xanthophylls.
$(II)$ They vary in color from olive green to various shades of brown.
$(III)$ Food is stored as complex carbohydrates,in the form of laminarin or mannitol.
$(IV)$ The cell wall is composed of cellulose and algin.
$(V)$ The cell wall is covered on the outside by a gelatinous coating of algin.

Which statement is correct for $Chlorophyceae$?

How many of the following algae belong to the category of red algae?
Polysiphonia,Gelidium,Laminaria,Spirogyra,Porphyra,Fucus,Chlamydomonas,Polytrichum

Laminarin is the stored food in

Which of the following hydrocolloids is obtained from brown algae?