Question

Sargasso Sea is named after an algae Sargassum muticum. It is a
A. Brown algae
B. Green algae
C. Red algae
D. Blue green algae

Answer 1

Hint: Sargassum muticum is commonly known as Japanese wireweed that belongs to the algal group containing chlorophyll a, chlorophyll c, and fucoxanthin. The reserved form of food in these algae is laminarin.

Complete answer:
Option (A) is correct. The Sargasso sea is named after an algae Sargassum muticum that belongs to the class Phaeophyceae or the class of brown algae. It is an autotroph that is normally brown to yellowish. Other examples of brown algae are Fucus, Laminaria.
Option (B) is incorrect. Green algae belong to the phylum Chlorophyta and are green. Pigments in green algae are chlorophyll a, chlorophyll b, and xanthophylls. The reserved form of food in green algae is starch. Examples include Volvox, Chlorella.
Option (C) is incorrect. Red algae belong to the phylum Rhodophyta and are red. Pigments in red algae are chlorophyll a, chlorophyll d, and phycobilins. The reserve form of food in red algae is floridean starch. Examples include Porphyra, Gelidium.
Option (D) is incorrect. Blue-green algae, also known as Cyanobacteria belongs to the phylum Cyanobacteria that is a phylum of prokaryotes. Sargassum muticum is an alga that is a eukaryotic organism and hence, it does not belong to blue - green alga which is a prokaryote.

Hence, the correct answer is option (A).

Note: Sargassum muticum belongs to the group of brown algae because it is brown to yellowish in color. It is highly tolerant towards variations in temperature and salinity. In agriculture, these algae have been used as sources of nitrate and potash. It has also been used in aquaculture as a feed for sea cucumbers.