Consider the following statements:
$I$. They reproduce asexually by non-motile spores and sexually by non-motile gametes.
$II$. In this class,sexual reproduction is oogamous and accompanied by complex post-fertilisation developments.
$III$. The common members are $Polysiphonia$,$Porphyra$,$Gracilaria$ and $Gelidium$.
The above characteristics belong to which class of algae?

The thallus organisation of $Volvox$ is

Which of the following algae is unicellular?

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.

Consider the following statements:
$I.$ In red algae,vegetative reproduction takes place by fragmentation.
$II.$ In red algae,the food is stored as floridean starch,which is very similar to amylopectin and glycogen in structure.
$III.$ The cell wall of red algae consists of chitin.
Which of the statements given above are correct?

Write a note on Rhodophyceae.