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 recognise any potentially mutation-causing damage and repair it before it becomes a fixed mutation.

Detailed explanation-2: -Mutations caused by environmental factors are generally induced mutations. Any outside agent that causes a change in DNA is called a mutagen. Mutagenic substances include radiation, chemicals, and high temperatures. Some mutagens cause DNA to break apart.

Detailed explanation-3: -Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection.

Detailed explanation-4: -Radiation is another type of environmental mutagen that may cause direct changes in a cell’s DNA. For instance, ionizing radiation (i.e., X-rays) can break DNA sequences in many places, leading to chromosome rearrangement. Lower-energy radiation, such as UV rays, can also penetrate cellular and nuclear membranes.

Detailed explanation-5: -Mutations result either from accidents during the normal chemical transactions of DNA, often during replication, or from exposure to high-energy electromagnetic radiation (e.g., ultraviolet light or X-rays) or particle radiation or to highly reactive chemicals in the environment.