Imagine that at the beginning of time on Earth, frogs were all different colors of the rainbow. Over generations almost all frogs became green because the color camouflaged them in their leafy environments. This is an example of

Which of the following is the best definition of a eukaryota? a. a one-celled organism that does not have a membrane-bound nucleus b. a one-celled organism that does not have a cell wall c. an organism whose cells each contain a membrane-bound nucleus d. an organism whose cells each have a cell wall