explain formation of genetics
Answers
➢ Formation of Genetics Branch
Based on historical activities, many people have tried to clarify the genetic rules between the traits of the parents and hybrid offspring. It was not until 1866 that the Austrian scholar Mendel published a paper on "Plant Hybridization Experiments" based on the results of his pea hybrid experiment, which revealed the genetic law now called Mendel's Law, which laid the foundation of genetics.
The results of Mendel's work were not valued until the early 20th century. In the late 19th century, in biology, researches on cell division , chromosomal behavior, and fertilization process and knowledge of genetic material, these two achievements promoted the development of genetics.
In the years from 1875 to 1884, German anatomist and cytologist Fleming found animals, and German botanist and cytologist Strassburg discovered mitosis , meiosis , and chromosomes in plants, respectively . Longitudinal splitting and bipolar behavior after splitting; Belgian zoologist Beneden also observed that each body cell of Ascaris lumbricoides contains an equal number of chromosomes; German zoologist Hertwig in the animal, Shi Trasberg discovered fertilization in plants separately; these findings have laid the foundation for hereditary chromosome theory . American zoologist and cytologist Wilson published the book "Cells in Development and Inheritance" in 1896 summarizing the findings of this period.
The material basis of genetics has always been speculated. For example, in 1864, the British philosopher Spencer called it a living particle; in 1868, the British biologist Darwin called it a bud; in 1884, the Swiss botanist Negri was called a heteroplasm; in 1889, the Dutch scholar De Vries called Pan children; in 1883 the German zoologist Weismann called Weismann said germplasm germplasm is actually no longer a mere speculation, and he has indicated. germ cell chromosome is the kind of Quality, and clearly distinguish germplasm and physique, think that germplasm can affect physique, and physique can not affect germplasm, in theory opened the way for the development of genetics
Mendel ’s work was discovered in 1900 by three scholars engaged in plant hybridization experiments , such as De Vries, German plant geneticist Correns, and Austrian plant geneticist Chelmark. In 1900-1910, in addition to confirming the inheritance of certain traits in plants such as peas, corn, etc. and chickens in animals, mice, guinea pigs, etc., in accordance with Mendel ’s law, some basic concepts of genetics were established. 1909 Danish plant physiology at home and geneticists Johnson said Mendelian inheritance of genetic factor gene, and a clear distinction between genotype and phenotype. In the same year, Bateson also coined terms such as allele, heterozygosity , and homozygosity, and published the representative work "Mendel's Genetic Principles".
The development of genetics from 1910 to the present can be roughly divided into three periods: cytogenetic period, microbial genetic period and molecular genetic period.