How much of the potential energy is transferred to the next trophic level? Hint: The Rule
of 10 is an average amount used when actual numbers are not available

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

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.