Why was there no ‘control’ leaf used in the starch experiment? Explain.
In a scientific experiment, a control group is used to provide a baseline for comparison with the experimental group. In the case of the starch experiment, the absence of a 'control' leaf may be due to the fact that the purpose of the experiment is to specifically investigate the presence of starch in leaves under different conditions or treatments.
In this case, the experimental group may consist of leaves exposed to different light conditions, water availability, temperature, or other factors, and the presence of starch in these leaves is being measured and compared. The absence of a control group in this experiment does not necessarily detract from its validity, as the focus is on comparing the effects of different variables on starch accumulation in the leaves, rather than comparing with a baseline control group.
Therefore, in some experiments like the starch experiment, a control group may not be deemed necessary or relevant to the research question being investigated.