Which ecosystem is the most resistant to permanent change?

Ascientist is studying muscle twitches in chicken quadriceps. to activate the muscle, he needs to provide stimulus to the

The chemical form of energy that is useable by the cell to do work

Aresearcher created three groups based on participants bmi: normal weight, overweight and obese. the hypothesis being tested is that the three groups differ in the mean number of artificially sweetened drinks consumed weekly. which statistical test might the researcher use, assuming a reasonably normal distribution of values.