Biology 1001A Lecture : lecture

• School: Western University
• Department: Biology
• Course: Biology 1001A
• Professor: Tom Haffie

Document Summary

--a mutation is a heritable change in dna (between 1 gamete in 100 000 and 1 in 1 million will include a new mutation at a particular locus). Mutations have been accumulating in biological lineages for billions of years. Mutation is a major source of heritable variation. --- for most animals: only mutations in the germ line ( the cell lineage that produce gametes) are heritable; mutations in other cell linages have no direct effect on the next generation. In plant, mutations may occur in meristem cells, which eventually produce flowers as well as nonreproductive structures; mutations can be passed on to generations. --deleterious mutations alter an individual s structure, function , or behaviour in harmful ways. Lethal mutations cause the death of organisms carrying them. If a lethal allele is dominant, both homozygous and heterozygous carriers suffer for its effect; if recessive , it affects only homozygous recessive individuals.