AP BIOLOGY

Detailed explanation-1: -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-2: -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-3: -Environmental mutagens, such as polycyclic aromatic hydrocarbons (PAH) and heterocyclic amines are known to bind to nucleotides, resulting in the formation of DNA adducts. Some DNA adducts are fixed as mutations through replication of DNA.

Detailed explanation-4: -Environmental mutagens are defined as chemical and physical agents in the environment that induce genetic mutations or increase mutation rates during the human life span [1]. Most mutagens act as human carcinogens or exert genotoxic effects on the next generation via germ cells.

Detailed explanation-5: -The mutagen produces mutations in the DNA, and deleterious mutation can result in aberrant, impaired or loss of function for a particular gene, and accumulation of mutations may lead to cancer. Mutagens may therefore be also carcinogens.