How tobbaco effects our body. how the usage of tobbaco causes cancer?

Tobacco: Tobacco contains nicotine, which provides pleasure, and the remaining additives preserve the nicotine and facilitate its entry into the bloodstream. These other substances can cause mutations in dna that allow cells to divide without responding to the body's signals to stop (cancer). These effects can be local, from chewing tobacco in the mouth, or systemic, by inhaling tobacco in the lungs.