Cyanobacteria
A) are a form of algae.
B) are prokaryotes.
C) use hydrogen sulfide as an electron source.
D) are eukaryotes.
E) contribute to global CO₂ buildup.

Question

Quizplus · Accepted Answer

Cyanobacteria are a type of bacteria, which are prokaryotes. They do not have a nucleus and other membrane-bound organelles like eukaryotic cells.

Answer: C
 Some cyanobacteria can use hydrogen sulfide as an electron source for photosynthesis, particularly in geothermal areas where sunlight may be limited.

Answer: E
 Cyanobacteria contribute to global CO2 buildup because they are primary producers that convert carbon dioxide into organic matter through photosynthesis. When they die and decompose, much of the organic matter is broken down into carbon dioxide, which is released back into the atmosphere.