<P> A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present , but is capable of switching to fermentation or anaerobic respiration if oxygen is absent . An obligate aerobe , by contrast , can not make ATP in the absence of oxygen , and obligate anaerobes die in the presence of oxygen . </P>
<P> A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present , but is capable of switching to fermentation or anaerobic respiration if oxygen is absent . An obligate aerobe , by contrast , can not make ATP in the absence of oxygen , and obligate anaerobes die in the presence of oxygen . </P>
an organism that can not grow without oxygen is a ( n )
an organism that can not grow without oxygen is a ( n )
anaerobe
anaerobe