Question

Which of the following is not a blue-green algae?

• A. Nostoc
• B. Anabaena
• C. Lichen
• D. Aulosira

Answer 1

Answer: (C)

Lichen

Blue-green algae (cyanobacteria) are photosynthetic, filamentous prokaryotes. The cells are without membrane bound cell organelles like chloroplast, mitochondria etc. Nostoc is free-living nitrogen-fixing cyanobacteria having cells arranged in beadlike chains (trichomes) that are grouped together in a gelatinous mass (Nostoc balls). They fix atmospheric nitrogen in specialized cells called heterocysts. Anabaena is a genus of cyanobacteria with beadlike or barrel-like cells and interspersed enlarged spores (heterocysts). Aulosira is a genus of cyanobacteria which forms colonies composed of filaments of moniliform cells. Whereas lichens are formed by the close association of 2 different partners, one is an algal component (phycobiont) and other is a fungal component (mycobiont).

Thus, the correct answer is option C.