The correct answer is C. The temperature of the water
Explanation:
In an experiment such as the one described about the speed of snails in water, the manipulated variable is the factor or element that is manipulated on purpose. This means the researcher or researchers slightly change this element to compare how this affects another variable. In this context, the manipulated variable is the temperature of the water because researchers used three different temperatures (cool, room-temperature, and warm), and therefore they manipulated or changed this factor. Moreover, it is expected temperature affects the distance nails move, which is the main variable.
20, as there are only 20 amino acids, which are what make up proteins
Answer:
The expression of the mRNA decreases.
Explanation:
The RNAi binds to some proteins forming a silencing complex. This complex binds to the target mRNA (of which the RNAi is complementary) and cleaves it (cuts it). The cell will detect the generated fragments of mRNA , recognize they are aberrant and will thus degrade them.
All in all, this mechanism silences (reduces) the expression of the mRNA, because it will be degraded instead of translated into protein.