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.
A human egg/sperm cell has 23 chromosomes. When the sperm and egg fuse together,, the zygote (fertilised egg) contains 46 chromosomes. Scientists call this the diploid number, â¦ with the sperm/egg having a haploid number of chromosomes. This number varies between species. human egg/sperm cell has 23 chromosomes. When the sperm and egg fuse together,, the zygote (fertilised egg) contains 46 chromosomes. Scientists call this the diploid number, â¦ with the sperm/egg having a haploid number of chromosomes. This number varies between species.