Which statement best defines biodiversity? a) the total number of different species in an area b) the number of communities in an ecosystem c) the number of tropic levels in a food web d) the total size of a population of a single species

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