Which term refers to a photosynthetic bacteria commonly found in marine environments?

• A. Cyanobacterium
• B. Dinoflagellate
• C. Copepod
• D. Angiosperm

Answer: (A)

Photosynthetic bacteria in marine environments are cyanobacteria. They are prokaryotes that carry out oxygen-producing photosynthesis and are major contributors to oceanic primary production. In surface waters, cyanobacteria such as Prochlorococcus and Synechococcus are extremely abundant, especially in nutrient-poor regions, making them key players in the marine carbon cycle. While some dinoflagellates are photosynthetic, they are eukaryotes, not bacteria. Copepods are heterotrophic zooplankton, and angiosperms are flowering plants. So cyanobacterium is the term that correctly identifies a photosynthetic bacterium commonly found in the ocean.