AP BIOLOGY

Detailed explanation-1: -Researchers know that there are several viruses that can lead to cancer. For example, the human papillomavirus (HPV) can cause cervical and several other cancers. And hepatitis C can lead to liver cancer and non-Hodgkin’s lymphoma.

Detailed explanation-2: -More recently, infections with certain viruses, bacteria, and parasites have been recognized as risk factors for several types of cancer in humans. Worldwide, infections are linked to about 15% to 20% of cancers.

Detailed explanation-3: -Cancer is caused by changes (mutations) to the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide.

Detailed explanation-4: -Some viruses do this by inserting their own DNA (or RNA) into that of the host cell. When the DNA or RNA affects the host cell’s genes, it can push the cell toward becoming cancer. In general, each type of virus tends to infect only a certain type of cell in the body.

Detailed explanation-5: -Oncolytic viruses kill individual cancer cells, but studies also suggest that they can boost the immune system’s ability to recognize and kill a tumor. The viruses enter tumor cells specifically and replicate, eventually breaking the cells apart.