In which situation has the independent variable for the experiment been changed? Check all that apply.

changed from counting the number of duckweed at day 0 and day 14 to counting them every day

changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks

changed from testing the effect of pH on duckweed growth to testing the effect of light levels on duckweed growth

changed from testing the effect of acid pH on duckweed growth to testing the effect of basic pH on duckweed growth

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.