The number of trophic levels in an ecological pyramid a. is limitless. b. is limited by the amount of energy that is lost at each trophic level. c. never exceeds four. d. never exceeds three.

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time