Correct Answer - B
(b) Blue-green algae or cyanobacteria are the largestt Gram negative, aerobic, photoautotrophic, nitrogen-fixing, simplest chlorophyll containing thallophytes/prokaryotes. They neither have a definite nucleus nor definite plastid with grana. They also lack flagella, chlorophyll-b, mesosome, meiosis and membrane bound organelles (except ribosome of 70S type).
