Which of the following shows the absence of chlorophyll $b$?

Hydrocolloid carrageen is obtained from:

$Chlamydomonas$,$Volvox$,$Ulothrix$,$Spirogyra$ and $Chara$ are examples of:

Consider the following statements regarding the major pigments and stored food in the different groups of algae and choose the correct option:
$(i)$ In Chlorophyceae,the stored food material is starch and the major pigments are chlorophyll $-a$ and $d$.
$(ii)$ In Phaeophyceae,laminarin is the stored food and major pigments are chlorophyll $-a$ and $b$.
$(iii)$ In Rhodophyceae,floridean starch is the stored food and the major pigments are chlorophyll $-a, d$ and phycoerythrin.

What is the stored food (nutrient) in algae?

$A$ : Sexual reproduction shows considerable variation in the type and formation of sex cells in members of $Chlorophyceae$.
$R$ : It may be isogamous,anisogamous and oogamous.