What statement best describes an independent variable?
a. the factor that does not change, but impacts the constant in an experiment
b. the factor that's changed by the experimenter and impacts the constant in an experiment
c. the factor that's not changed by the experimenter and is impacted by the dependent variable
d. the factor that's changed by the experimenter and impacts the dependent variable

Apopulation of bears has genetic diversity. some of the bears have an allele that gives them thicker fur. due to climate change, the winters have gotten colder in their habitat. now the bears with thicker fur are becoming more common in the population. a.) which type of bear is selected for in the coldest ecosystem? b.) what must be the other allele for the type of fur, and what term would you use to describe the fact that the allele is becoming less common in the colder climate? c.) describe the change in the bear population in terms of changing allele frequencies and phenotypes d.) is this an example of natural selection