In the middle of the 19th century the Austrian scientist Gregor Mendel opened the main regularities of genetic inheritance. Opening of the scientist was the base for development of genetics. In 1953 the structure of DNA which provides storage and transfer from generation to generation of the genetic program was deciphered.
Instruction
1. Cells of a human body contain two DNA codes – on the maternal and fatherly line. At conception genetic information mixes up in a unique combination of signs. To foretell what will be genetic set at the person, very difficult. Attempts to predict are made by scientists-geneticists, but the person cannot provide all options yet.
2. In formation of genetic signs of the person accept strong and weak genes. Strong genes – prepotent. It means that such genes will suppress manifestation of weak genes and to define manifestation of external sign.
3. Weak genes – recessive, that is in the presence of prepotent genes such genes will not define external signs. Recessive genes can provide manifestation of sign only in case are together with the same recessive genes.
4. Scientists-geneticists defined the dominating external signs at the person. If one of parents has a direct section of eyes, Mongoloid type of eyes, the hanging upper eyelid, long eyelashes, dark color of eyes, full lips, dimples on cheeks, freckles, an aquiline nose, dark and curly hair – that, most likely, at the child these signs will be shown.
5. Also treat the dominating signs: so-called "Habsburg" lip, short skull, round shape of the face, outstanding cheekbones, aquiline nose, wide nostrils and large ears. Early baldness at men, the tendency to a premature posedeniye, plentiful hairiness of a body and swarty skin are defined by the dominating genes too.
6. Recessive external signs can not be shown if one of parents does not have them. If both parents bear in themselves recessive genes, then at the child these signs can be present. Refer to recessive signs: small eyes, Caucasian type of eyes, short eyelashes, gray or blue eyes, lack of freckles, fair or red hair, light skin.
7. The appearance of the person is a result of mixture of a set of genes. If the father has a prepotent gene of dark hair, and at the woman a recessive gene of a fair hair, most likely, the child will have dark hair. The next generation can have a fair hair as the child inherited two genes – a prepotent gene of dark hair and a recessive gene of a fair hair. If the recessive gene of a fair hair meets the same recessive gene at conception, then the child will be born fair-haired.