Which statement is correct for $Chlorophyceae$?

In $Ulothrix$ / $Spirogyra$,the reduction division (meiosis) occurs at the time of:

The cell wall of algae is composed of:

Approximately $9/10$th of the total photosynthesis on Earth is carried out by ...........

$(i)$ Green algae occur in fresh water,brackish water,and salt water.
$(ii)$ Habitat of Brown algae: fresh water (rare),brackish water,and salt water.
$(iii)$ Some red algae are found in fresh water,mostly occur in salt water,and some are in brackish water.
$(iv)$ Most of the red algae are multicellular.
$(v)$ Red algae may occur in both well-lighted regions close to the water surface and also at great depths in oceans where light penetration is little.
$(vi)$ The cell wall of red algae consists of cellulose $+$ agar.
$(vii)$ $2-8$,equal and apical flagella in green algae.

Match the following columns:

Column-$I$	Column-$II$
$P$. Oogamous	$I$. Spirogyra,Chlamydomonas
$Q$. Anisogamous	$II$. Volvox,Fucus
$R$. Isogamous	$III$. Some species of Chlamydomonas