If a cell that has been isolated from the root of a carrot is given the appropriate nutrients and cues, it will give rise to a mass of undifferentiated cells, which can go on to develop into a a. carrot that is genetically distinct from the original. b. carrot embryo called a callus. c. variety of different plants. d. root of a carrot that is genetically distinct from the original. e. clone of the original carrot. If a mutant plant were created that lacked the receptor for ethylene, its fruit would a. process ethylene in a positive-feedback loop rather than a negative one. b. process ethylene in a negative-feedback loop rather than a positive one. c. not ripen unless exposed to an additional source of ethylene. d. fail to develop entirely. e. not ripen as it aged..