Two different species of bacteria are examined. They find that species X always produce CO2 and H2O during cellular respiration. and Y produces ethyl alcohol and CO2. Which could be a conclusion?

Question

1/ Only species Y is anaerobic.
2. Only species Y is aerobic.
3. Both X and Y and anaerobic.
4. Both X and Y are aerobic.

Answer 1

Based on the information provided about the two species of bacteria and their cellular respiration products:

• Species X produces CO2 and H2O, which indicates that it undergoes aerobic respiration (the presence of water suggests the use of oxygen).
• Species Y produces ethyl alcohol (ethanol) and CO2, which indicates that it undergoes fermentation, generally associated with anaerobic respiration (as it typically occurs in the absence of oxygen).

From these definitions, we can draw the following conclusions:

1. Only species Y is anaerobic. (Correct, as it produces ethanol typically under anaerobic conditions).
2. Only species Y is aerobic. (Incorrect, as Y does not require oxygen).
3. Both X and Y are anaerobic. (Incorrect, as X is aerobic).
4. Both X and Y are aerobic. (Incorrect, as Y is anaerobic).

Therefore, the correct conclusion is: 1. Only species Y is anaerobic.