mendelian genetics

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men·de·li·an ge·net·ics

the study of the pattern of segregation of phenotypes under the control of genetic loci taken one at a time.

mendelian genetics, mendelian laws

Mendelian genetics


Mendel's laws

the basic laws of inheritance, first published by Gregor MENDEL in 1866 to explain the results he obtained from experiments with the garden pea. Working without detailed knowledge of cell structure or nuclear division he suggested that:
  1. each character (e.g. height) is controlled by two factors. We would now state this idea as each gene having two alleles, one on each HOMOLOGOUS CHROMOSOME.
  2. each factor segregates in the egg and pollen grains. We would now state that MEIOSIS separates allelic forms of gene (Mendel's first law - see SEGREGATION).
  3. factors for different characters show INDEPENDENT ASSORTMENT. We would now state that genes are assorted independently during meiosis (Mendel's second law), unless linked on the same chromosome.
  4. factors do not cause blending, but are either dominant (see DOMINANCE (1) or recessive. We know now that we can explain dominance in terms of enzyme activity, and that sometimes two alleles code for enzymes giving an intermediate phenotype when together (see INCOMPLETE DOMINANCE).
  5. the distribution of factors in the egg cells and pollen grains obey basic statistical laws giving ratios in the progeny which are predictable.
  6. results from crosses are the same whether the dominant form of the character belongs to the female parent or the male parent. We now know that this statement is true only if the gene is located on an AUTOSOME (see SEX LINKAGE).
References in periodicals archive ?
Difficulties experienced by high school students when learning basic Mendelian genetics.
Some students' explanations demonstrated that they had embraced the neo-Darwinian model, which depends on both Mendelian genetics and evolution by natural selection:
Epigenetics is a tremendously exciting and evolving area of research today and will unquestionably challenge some dearly held tenets of Mendelian genetics.
Indeed, Mendelian genetics as a science may be said to date from the dawn of the twentieth century, nearly two decades after Mendel's death in 1884.
So at the turn of the 20th century, scientists with a can-do spirit and just enough knowledge of Mendelian genetics to be dangerous devised grand schemes to improve the American "protoplasm": They would segregate, sterilize, and perhaps even murder those deemed "unfit"--as much as 10 percent of the population.
Mendelian genetics refers to the simple quantitative inheritance of genes that express themselves in defined and predictable phenotypes.
Mendelian genetics still provides a sufficient explanation for many inherited diseases.
From Newtonian physics and Mendelian genetics to cutting-edge chaos theories, science explains how and why the world--including the business world--works the way it does.
The author focuses on two pivotal events in this conflict: the 1939 discussions which gave the Lysenkoists only a partial victory over the geneticists, and the infamous 1948 meeting of the Lenin All-Union Academy of Agricultural Sciences (VASKhNiL) which outlawed Mendelian genetics and supported Lysenko's ideas of "Michurinist Biology.
Explaining scientific consensus: The case of mendelian genetics (pp.
Telling in this regard is The Bell Curve's misunderstanding of Mendelian genetics.
The core of Mitman's work is an insightful working-out of Allee's and Emerson's development of animal ecology and their response to the revival of the Darwinist program and its synthesis with Mendelian genetics.