AP BIOLOGY

Detailed explanation-1: -Cancer-related genetic changes can occur because: random mistakes in our DNA happen as our cells multiply. our DNA is altered by carcinogens in our environment, such as chemicals in tobacco smoke, UV rays from the sun, and the human papillomavirus (HPV) they were inherited from one of our parents.

Detailed explanation-2: -Genes contain information to make proteins, and proteins control many important functions like cell growth. Genetic mutations can change how proteins function. Some types of genetic mutations change proteins in ways that cause healthy cells to become cancerous.

Detailed explanation-3: -The nucleotide sequence in DNA may be modified either spontaneously or from exposure to heat, radiation, or certain chemicals and can lead to mutations. Mutagens are the chemical or physical agents that cause mutations.

Detailed explanation-4: -Random, unpredictable DNA “mistakes” account for nearly two-thirds of the mutations in cancers. These mutations occur as a result of DNA copying errors made when normal cells divide.

Detailed explanation-5: -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.