Maximum number of chloroplasts recorded in Spirogyra is

The simplest green plants are

Read carefully the given statements about algae and choose the correct option.
$I$. The plant body is thalloid.
$II$. Mainly aquatic.
$III$. Reproduction takes place by vegetative,asexual,and sexual methods.
$IV$. Volvox and Ulothrix are the colonial forms of algae.

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.

State the location and composition of pyrenoids.

Agar,which is required for the synthesis of ice cream and jelly,is obtained from: