American student, David - not his real name - explains why he chooses to buy illegal drugs on the so-called 'dark web'. You don't have to go in front of a street dealer, where there might be a risk of violence, he adds. And it is not just drugs which are available on this online black market. Fake passports, guns - even child pornography.
Genetic material is that substance which not only controls the inheritance of traits from one generation to the next but is also able to express its effect through the formation and functioning of the traits. Components of genetic material which control characters are called genes. Genes are located over chromosomes. In sexually reproducing organisms, an indiÂ­vidual receives one genome or one set of chromosomes (and hence genes) from male parent and a second genome or set of chromosomes from female parent.
Gene mutations can be classified in two major ways: 1  Hereditary mutations are inherited from a parent and are present throughout a personâs life in virtually every cell in the body. These mutations are also called germline mutations because they are present in the parentâs egg or sperm cells, which are also called germ cells.