Final answer:
DNA damage can indeed result from exposure to chemicals, as these can act as mutagens that modify the structure or sequence of DNA. While our cells have repair mechanisms in place, if these fail, the resulting mutations can lead to various illnesses, including cancer.
Step-by-step explanation:
Can DNA damage occur as a result of exposure to chemicals? The answer is True. Exposure to certain chemicals can indeed cause damage to DNA, playing a role in various cellular dysfunctions and diseases including cancer. Some chemicals are classified as mutagens, which means they can change the structure or sequence of DNA. For example, industrial chemicals like vinyl chloride and hydrogen peroxide, as well as environmental chemicals such as polycyclic hydrocarbons found in smoke, soot and tar, have been shown to cause a wide array of DNA adducts and alterations. These changes to DNA can affect its primary structure, introducing abnormal chemical bonds or adducts that disturb the helical structure of DNA, with the potential to lead to mutations.
Furthermore, it's important to note that not all mutations are caused by toxic substances, as they may also result from endogenous cellular processes like oxidative deamination. In fact, our cells have repair mechanisms that correct over 99.9% of mistaken base changes, preventing them from becoming permanent mutations. This means that most DNA replication processes are incredibly accurate, but when repair mechanisms fail, mutations can occur, which may make chromosomes longer or shorter.