AP BIOLOGY

Detailed explanation-1: -A mutation is a change in the DNA sequence of an organism. Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection.

Detailed explanation-2: -“We always thought of mutation as basically random across the genome, ” said Grey Monroe, an assistant professor in the UC Davis Department of Plant Sciences who is lead author on the paper. “It turns out that mutation is very non-random and it’s non-random in a way that benefits the plant.

Detailed explanation-3: -For example, exposure to harmful chemicals may increase the mutation rate, but will not cause more mutations that make the organism resistant to those chemicals. In this respect, mutations are random-whether a particular mutation happens or not is unrelated to how useful that mutation would be.

Detailed explanation-4: -Genetic drift describes random fluctuations in the numbers of gene variants in a population. Genetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time.

Detailed explanation-5: -Mutations result either from errors in DNA replication or from the damaging effects of mutagens, such as chemicals and radiation, which react with DNA and change the structures of individual nucleotides.