Substances that cause DNA mutations are known as mutagens, and mutagens that cause cancers are known as carcinogens. Particular substances have been linked to specific types of cancer. Tobacco smoking is associated with many forms of cancer, and causes 90% of lung cancer.
Human diploid cells have 46 chromosomes and human haploid gametes (egg and sperm) have 23 chromosomes. Retroviruses that contain two copies of their RNA genome in each viral particle are also said to be diploid.
In humans, a pair of chromosomes called SEX CHROMOSOMES determine the sex. If you have XX sex chromosomes - you are female. If you have XY sex chromosomes - you are male. During fertilization, sperm cells will either contain an X or a Y chromosome (in addition to 22 other chromosomes - total of 23).