If a small number of tree frogs migrate to a mat of vegetation that is already home to an established population of tree frogs and introduce new alleles into the native population's gene pool, this change is referred to as a the bottleneck effect. b directional selection. c genetic drift. d gene flow.

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.