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

or

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.
Epigenetics is a tremendously exciting and evolving area of research today and will unquestionably challenge some dearly held tenets of Mendelian genetics.
I did not receive the software until early March of the school year, when we were beyond the genetics unit, so I was not able to use the Mendelian Genetics and fruit fly modules with my sophomores.
Topics covered include analytic methodologies in the field, the composition of biomolecules, the rediscovery of Mendelian genetics, and plant production of and response to chemical signals.
MOUSE OF A DIFFERENT COLOR As early as the 1940s, researchers who couldn't explain some of an organism's attributes by straightforward Mendelian genetics started calling these aberrant traits epigenetic, says Randy Jirtle, a researcher who studies gene control at Duke University in Durham, N.
Thus, both transgenic and non-transgenic traits are expected to behave according to classical Mendelian genetics.
Bowler also hints at the ways in which Darwinians later needed the work of historically-minded scientists (as well as Mendelian genetics, field and statistical work) in order to reinvent the theory of natural selection in the early twentieth century.
Plant reproduction and Mendelian genetics (Matthew D Halfhill and Suzanne I.
How-to-do-it: hands-on activities that relate Mendelian genetics to cell division.
Coverage progresses from fundamentals of cytogenetics and Mendelian genetics through techniques for gene manipulation and mapping and the molecular genetics of distinct biological systems.
According to Mendelian genetics, neither child should have suffered ill effects because each got a normal and complete set of genetic material, albeit from only one parent.