What are food webs and food chains dependent on?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Fungi are classified into how many groups? a. 1 group b. 2 groups c. 3 groups d. 4 groups

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.