Question

The pigment present in Porphyridium is
a) Xanthophyll
b) Phycoerythrin
c) Phycocyanin
d) None of the above

Answer 1

Porphyridium belongs to Rhodophyceae. These algae are unicellular and are found in marine habitat. They are red algae which contains red protein pigment which is used in making food.

Complete answer:
To solve this question, we must know about the types of pigments and where they are present.
Porphyridium is a red micro-algae which is unicellular. They are widely exploited due to the pigments, fatty acids and other cellular compounds they produce. They are photosynthetic in nature and have a red protein pigment called the phycoerythrin in them. It constitutes around 60-$70\%$ of the total soluble proteins present in them. They also contain other pigments like chlorophyll a, beta-carotene, zeaxanthin etc.
Xanthophyll- It is a carotenoid pigment responsible for colours like yellow, orange, to flowers, fruits, vegetables etc. It is an accessory pigment which prevents the plants or plant parts from the damage of the sun.
Phycocyanin- It is a blue colour photosynthetic pigment which is found in blue-green algae. It is also an accessory pigment to chlorophyll. It exhibits an anti-oxidant and anti-inflammatory effect.

Thus, the correct answer is option B.

Note:
Phycoerythrin is an accessory pigment present along with chlorophyll which is used in photosynthesis by the algae. In red algae, they are present in the stroma side of the thylakoid in the chloroplast. These pigments emit fluorescence which is used in immunofluorescence microscopy. They are used in labelling the antibodies. Phycoerythrin are the best fluorescent dyes.