Answer:
Ideally, the experimental and control groups are identical. As much as possible, the two groups should overlap in every characteristic.
Explanation:
At the beginning of your study, you need your two groups to be as statistically similar as is humanly possible. That way, when you control for other variables, you can reasonably attribute any statistically significant differences at the end of the study to your intervention.
I can answer the third one:
Photosynthesis takes place in two stages<span>: light-dependent reactions and the Calvin cycle (light-independent reactions).</span>
The correct answer for the given statement above would be true. Yes, it is true that local topography and sea surface temperature contribute to differences in climate between various localities. In fact, these factors contribute largely towards variations in the climate of places. Hope this answers the question.
