AP BIOLOGY

Detailed explanation-1: -The red “algae" Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize and live at somewhat greater depths than most other “algae".

Detailed explanation-2: -Brown algae have photosynthetic pigments like chlorophylls a and c and also have fucoxanthin pigment (Which also causes their green-brownish color). Red Algae have chlorophylls a and c as photosynthetic pigments and phycoerythrin as their third pigment, which is responsible for their reddish color).

Detailed explanation-3: -Red algae, like Gracilaria, Gelidium, Euchema, Porphyra, Acanthophora, and Palmaria are primarily known for their industrial use for phycocolloids (agar, algin, furcellaran and carrageenan) as thickening agent, textiles, food, anticoagulants, water-binding agents etc.

Detailed explanation-4: -Red pigment allows the red algae to photosynthesize at deeper depths than the green or brown algae, harnessing more of the blue light waves that penetrate deeper into the water column. Unlike green algae and plants, red algae store carbohydrates as Floridean starch in the cytosol.