Distinguish between: (a) Facultative anaerobes and facultative aerobes; (b) Photoautotrophs and chemoautotrophs; (c) Gram negative bacteria and gram positive bacteria.

(a)

Facultative anaerobes	Facultative aerobes
A facultative anaerobe is an organism that makes ATP by aerobic respiration.	A facultative aerobe is an organism that makes ATP by anaerobic respiration.
These bacteria require oxygen but can survive in absence of oxygen.	These organisms do not require oxygen but can survive in presence of oxygen.
They generate ATP by fermentation.	They generate ATP by aerobic respiration.

Photoautotrophs	Chemoautotrophs
These organisms obtain their energy from the proton.	These organisms obtain their energy by oxidizing electron donor.
An energy source is a sunlight.	An energy source is the oxidizing energy of chemical compounds.
They use sunlight, carbon dioxide and water to convert it into organic materials.	They use inorganic energy to synthesize organic compounds from carbon dioxide.

(b)

Gram-negative bacteria	Gram-positive bacteria
The outer membrane is present.	The outer membrane is absent.
The wall contains 10-20% murein.	The wall contains 70-80% murein.
Lipid content in the wall is 20-30%.	Lipid content in the wall is very low.
Teichoic acid are absent.	Teichoic acid are present.