Plantlike photosynthesis that releases o2 occurs in
(a) cyanobacteria.
(b) archaea.
(c) gram-positive bacteria.
(d) chemoautotrophic bacteria

Cyanobacteria. (Ans. A)

Explanation:

Cyanobacteria are prokaryotes, are a phylum of bacteria. They are also called as blue-green algae and obtain their energy through the process of photosynthesis. They are commonly found in fresh water and terrestrial environment such as land, in rocks even in animal cells (fur).

Cyanobacteria are photosynthetic (oxygenic) bacteria. They harvest the energy of sun, absorb carbon dioxide and release O2. Cyanobacteria also contain chlorophyll such as plants and algae and convert carbon dioxide to sugar through the process of carbon fixation.

Cyanobacteria lack nucleus and other organelles like found in algae and plants. Instead of these they have double outer cell membrane and folded inner thylakoid member which are used in the process of photosynthesis.