The two main sources of genetic variation are mutations and recombinations of genes as a result of sexual reproduction. A mutation is a permanent change in the DNA within a gene.Know More
Some mutations, which affect all cells in an organism, are inherited from a parent. Other mutations develop during an organism's life and occur in only some cells. Mutations are not always harmful. For instance, although the disease sickle cell anemia is caused by a mutation, that modified DNA also helps prevent malaria in some people.
Sexual reproduction causes genetic variation because of three factors. During the cell division that produces eggs and sperm, genetic material is exchanged. When these sex cells are formed, chromosomes are assorted by chance. In addition, a random egg and sperm combine during fertilization.Learn more about Molecular Biology & DNA
The four main types of chromosomal mutations are deletion, duplication, inversion and translocation. A fifth chromosomal mutation is known as a deficiency. This occurs when a chromosome is lost sometime during fertilization or development of a fetus.Full Answer >
The NIH Genetics Home Reference Handbook explains that mutations are passed to offspring if these mutations are present in germ line (sperm or egg) cells. Germ line mutations can occur early in the parent's development so that they affect all of the cells in the parent's body, including eventual gametes. These mutations can also occur in gametes alone and therefore only affect offspring.Full Answer >
Mutations in an individual or population are necessary for adaptation to the environment, which is the driving force behind evolution. Without natural mutations, living organisms would not progress or evolve as a population in response to variable environmental stimuli.Full Answer >
The disadvantages of cloning include increased risk of inherited diseases, lack of gene variation, ethics and religious dogma associated with it. The term cloning refers to a number of processes used in producing genetically identical copies of a biological entity.Full Answer >