The answer is mutagens. In genetics, mutagen is a physical or chemical agent that changes the genetic material usually that of DNA of an organism and thus increases the frequency of mutations above the natural background level. DNA changes caused by mutagens may harm cells and cause certain diseases such as cancer.
Metabolism refers to all of the chemical reactions that take place inside living cells. Unicellular and multicellular organisms must control their metabolism in order to survive.
Answer:

solar wind
The magnetosphere is the region of space surrounding Earth where the dominant magnetic field is the magnetic field of Earth, rather than the magnetic field of interplanetary space. The magnetosphere is formed by the interaction of the solar wind with Earth's magnetic field.
The main advantage is that it is relatively a fast process. It produces 2 ATP's. It also does not require oxygen.
As the fork moves forward, the DNA polymerase must come off and reattach on the newly exposed DNA.