| Home | About | Contact | Site Map | Links | Library |
Unique Home Furniture, Home Decorating and Home Decoration Store
Hereditary Materials:
The second category, physiological genetics, deals with the nature and action of the gene. It includes such specialty fields as (1) mutation genetics, the study of induced and spontaneous mutations; (2) biochemical genetics, the study of the chemical nature of hereditary materials; and (3) developmental genetics (or phenoge-netics), the study of the relationship between genes and the development of character.Many hereditary diseases can be controlled —hemophilia, for instance, by the use of coagulant drugs—but there are others for which no effective treatment is known. And even if the diseases could be successfully treated, the treatment would only ease the symptoms; it would not change the gene that causes them. Thus, descendants of a successfully treated individual could still inherit the unchanged, defective gene. One of the most exciting research projects currently under way in the study of hereditary diseases, in fact, is the technique of genetic surgery. Here the scientist seeks to change the actual chemical structure of the cell to eliminate the gene that causes the defect.
Transmission genetics, which is concerned with the transmission of hereditary materials, has four subdivisions: (1) Mendelian (classical) genetics, the study of inheritance of major genes; (2) biometrical genetics, the study of continuous variation in inheritance; (3) cytogenetics, the study of the relation of chromosome behavior to inheritance; and (4) cytoptasmic genetics, the study of inheritance through the cytoplasm (the cellular material outside the nucleus of a living cell).
.
