Bacteria are
single celled microorganisms. They have a simple cell structure than other
organisms because they have no nucleus and no cell membrane. Their control
center containing the genetic information si contained in a single loop of DNA.
They are classified into five groups according to their shape; cocci are
spherical, bacilli are rod shaped, spirilla are spiral, vibrios are comma and
spirochaetes are corkscrew. They can exist as singe cells in pairs, chains or
clusters. Rod shaped bacteria are called bacilli. The answer is letter C.
