AP BIOLOGY

Detailed explanation-1: -Mutations can also occur as the result of exposure to environmental factors such as smoking, sunlight and radiation. Often cells can recognize any potentially mutation-causing damage and repair it before it becomes a fixed mutation. Mutations contribute to genetic variation within species.

Detailed explanation-2: -Mutations, the changes in the sequences of genes in DNA, are one source of genetic variation. Another source is gene flow, or the movement of genes between different groups of organisms. Finally, genetic variation can be a result of sexual reproduction, which leads to the creation of new combinations of genes.

Detailed explanation-3: -Mutations can be caused by high-energy sources such as radiation or by chemicals in the environment. They can also appear spontaneously during the replication of DNA. Mutations generally fall into two types: point mutations and chromosomal aberrations. In point mutations, one base pair is changed.

Detailed explanation-4: -Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection. Germline mutations (that occur in eggs and sperm) can be passed on to offspring, while somatic mutations (that occur in body cells) are not passed on.

Detailed explanation-5: -Figure 2: Mutations can occur in germ-line cells or somatic cells. Germ-line mutations occur in reproductive cells (sperm or eggs) and are passed to an organism’s offspring during sexual reproduction.