Question

Ampicillin-resistant bacterial population (Strain 1) is grown in a laboratory is infected with a virus. The virus initially goes through the lytic cycle and thus bacterial population begins to decline, then rebounds as the virus integrates
into the bacterial chromosome to begin the lysogenic cycle. The bacteria reproduce normally until they are heat-shocked. The virus removes itself from the bacterial genome and enter the lytic cycle because of the temperature is increasing rapidly. Within several hours all bacteria are dead and a free virus is found in high concentration in the bacterial growth medium. This free virus infects bacterial population that is sensitive to ampicillin (Strain 2). After the expected decrease and rebound of this bacterial population (as above), the rebounded population was found to be ampicillin-resistant. Oxygen is constantly infusing in bacterial culture to ensure a high rate of reproduction among the bacteria and a health.

• A. Obligate aerobes
• B. Obligate anaerobes
• C. Tolerant anaerobes
• D. Facultative anaerobes
• E. Simple anaerobes

Answer 1

The correct option is D Facultative anaerobes

Organisms that use oxygen when it is available and survive by fermenting when oxygen is not available are classified as facultative anaerobes.

Facultative anaerobe - a microorganism that can live and grow with or without molecular oxygen. Whereas an obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy. Thus, the correct answer is option D.