You have conducted an ames test on a given compound. which of the following would be classified as a positive result on the ames test?

(a) his+ strain grows on an his- plate.
(b) his- strain grows on an his+ plate.
(c) his+ strain grows on either an his- or an his+ plate.
(d) his- strain grows on an his- plate.
(e) his+ strain grows on an his+ plate

The correct answer is option (D) "His- strain grows on an his- plate".

Explanation:

The Ames test is a procedure that allows to detect if a given compound can cause mutations on a tested organism by growing strains of bacteria that require histidine (His-) to growth, since they are not able to produce its own histidine. In the Ames test, the bacteria is exposed to a given compound and is grown in a medium with small amount of histidine (his- plate). If the His- strain grows on a his- plate, it means that the bacteria has mutated to synthesize its own histidine and it is considered as a positive result on a the Ames test.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.