Answer:
Experimental or interventional studies compare the effect of treatments or interventions with control in humans. Placebo or different treatment(s) or intervention(s) may be used as control. Experimental studies have to be transparent and evidence-based. Two examples include clinical studies as well as observational drug studies.
The correct answer is option:
The peak of the bell curve has shifted to the right, with a greater frequency of crickets with long legs and a lower frequency of crickets with short legs.
The given condition would lead the directional selection of the crickets with long legs. Directional selection leads to shifting of curve in one direction, which is more suitable.
The crickets with short leg get easily caught by predators, so, after sometime, there would be a decrease in number of the crickets with short leg. At the same time, the crickets with long leg would manage to save themselves and their number would comparatively increased.
