Describe in detail how insertion, deletion, and base substitution of nucleotides can have a significant impact on genes. Find three specific examples (actual gene mutations, not chromosome mutations) of ways in which a very small change in DNA can have a major impact on an organism, and describe each mutation in detail.

Why do agricultural researchers intentionally produce polyploid crop plants? Explain in detail what polyploidy means and discuss different types of polyploid plants. Give four specific detailed examples of actual commercial crops that are polyploid. In each case explain why polyploidy is advantageous. Also, indicate whether the polyploidy occurred naturally or describe how botanists created the new varieties. Why is it more common for polyploidy to occur in plants than in animals? Give examples of types of animals that have been found to exhibit polyploidy.