Cell mutations occur constantly, but most of them do not lead to any significant changes in the body. However, those that occur in germ cells (called generative) may be inherited. The range of manifestations of mutations is very wide: from subtle
Cell mutations occur constantly, but most of them do not lead to any significant changes in the body. However, those that occur in germ cells (called generative) may be inherited. The range of manifestations of mutations is very wide: from subtle or mild, such as changing hair color or shape of the nose, to severe illnesses or birth defects.
The variation of mutations can be divided into chromosome and gene. The latter include the restructuring of
sequence of nucleotide bases in a gene replacement of some other reason, the addition or deletion of one or more bases. Typically, they affect the function of only one gene. Manifestations of chromosome mutations involving several genes, much larger.
Human gene mutations lead to changes in the synthesis of a specific enzyme, which is controlled by the gene. Manifestation of the change depends on the role of this enzyme in the body. If he participates in the growth process, such a mutation can cause growth disturbances, and if involved in the process of digestion, digestive disorders arise, and so on.
However, almost all the genes of the human body are connected in pairs, and the production of enzymes, even in the presence of the mutant gene can be determined by a given pair of normal. The abnormal gene in this case is recessive, and that mutation manifested, both genes must be a pair of mutant, which means it must be present in both parents. Mutant genes that suppress the action of the normal is call