Which of the following does NOT describe bacteria?
a) They produce most of the Earth's oxygen and clean the air of pollution. b) They help break down food in the human intestines. c) They help break down harmful products. d) They help break down dead organic material so it can be recycled into a usable form for other organisms.
"A" does not describe bacteria. Bacteria use cellular respiration to produce energy, and therefore do not produce oxygen. However, millions of years ago, cyanobacteria did produce oxygen.
