Question

Facultative anaerobes such as E. coli

Group of answer choices

require O₂ for growth

require the absence of O₂ for growth

do not require O₂, but use it when it is available

do not require or use O₂, but can tolerate it

Answer 1

Facultative anaerobes use oxygen when available, but can grow without oxygen as well.Therefore option 3 is the right answer.

Option 1 is wrong because organsisms that require oxygen for growth are termed aerobes.

Option 2 is wrong because organsisms that require absence of oxygen for growth are termed obligate anaerobes.

Option 4 is wrong because facultative anaerobes use oxygen when it is available.