Wisconsin Fast Plants – Monohybrid Cross Experiment Lab questions 1-­‐3 ANSWER KEY 1. Explain how you will answer the question of whether stem color is genetically determined or based on an environmental condition. This question can be answered by crossing a purple-­‐stemmed with a green-­‐stemmed plant. If the color is inherited (i.e. a genetic characteristic), the offspring in the F2 generation will have different colors of stems. If the color is determined by the environment, it will affect most, if not all, of the offspring in the same way, so all offspring in the F2 generation will have the same stem color. Further, environmentally induced characteristics can be changed by modifying the environment, so if there is still a question after the F2 generation is observed, you can alter the environment and see if all plants still exhibit the same stem color. 2. If a single gene, two alleles, controls stem color, how will you determine which color is dominant and which is recessive? If a single gene is responsible, the dominant phenotype (stem color) will be observed in the F1 generation more frequently. 3. State your hypothesis about the inheritance of stem color. Explain what you expect to see in the F1 generation. Answers will vary, but should be stated as a TESTABLE “prediction”