Question

Which type of algae are helpful in nitrogen economy?

• A. Green algae
• B. Blue green algae
• C. Red algae
• D. Brown algae

Answer 1

The correct option is B Blue green algae

The majority of blue-greens are aerobic photoautotrophs, their life processes require only oxygen, light and inorganic substances. At the onset of nitrogen limitation, during bloom conditions, certain cells in Anabaena evolve into heterocysts, which convert nitrogen gas into ammonium, which is then distributed to the neighboring cells of a filament. In addition, blue-greens that form symbiotic (mutually beneficial) relationships with a wide range of other life forms, can convert nitrogen gas into ammonium.

Therefore, the correct answer is option B.