Question

The amount of usable energy from anaerobic respiration is less than the amount of useable energy from aerobic respiration because

aerobic respiration produces products that are not completely broken down.

the waste products of anaerobic respiration contain a lot of unprocessed energy.

the waste products of anaerobic respiration contains no more useable energy.

aerobic respiration is not as efficient.

Answer 1

Respiration is simply the breakdown of glucose into energy. It can be done with or without oxygen, but with oxygen, glucose can be broken down into 38 units of energy storing ATP molecules, and without, each glucose molecule is turned into only 2 units of ATP.

First one is false, anaerobic respiration is the type that produces products that aren't broken down completely, for example, lactic acid.

Second one is probably true, another byproduct of anaerobic respiration is ethanol, which contains prodigious amounts of energy.

The third one is false (because the second one contradicts it)

The fourth one is false, because aerobic respiration produces 19 times more energy than anaerobic respiration does.

I would go with #2.

Source: http://www.buzzle.com/articles/aerobic-and-anaerobic-respiration.html