KEY FOR QUIZ 1: MUTATIONS Topic # 3034 1. What is a mutation? Sudden change in the characteristics of an organism due to a change in the chemical structure 2. Choose one of the two useful mutants and discuss how it is beneficial to agriculture. Rust resistant wheat Plant breeders took advantage of this natural mutation and breed it into other wheat strains High Protein corn Plant agronomists and geneticists have continues over the years to always select for the high protein varieties and have tried to breed them exclusively. This selection for the variety producing a higher protein is a "man-made" selection rather than one based solely on "natural selection" for desirable traits. 3. How do mutations occur? Error in DNA replication Exposure to radiation Exposure to certain toxic chemicals Other genetic abnormalities such as extra chromosomes or chromosomes crossing or breaking 4. Why are mutations that harm less likely to survive than one that benefit? Ones that are harmful do not survive to reproduce and those that are beneficial do survive and can pass the mutation on to their offspring.