Tumors that will not spread throughout the body are and those that do spread are termed a. malignant; benign b. benign; malignant c. mutagen; carcinogen d. tumor suppressor; proto-oncogene e. benign; mutagen

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).