Mendelian Genetics

∞ generated and posted on 2016.08.28 ∞

Study of heredity based on the phenotype of offspring following experimental crosses of parent organisms.

In Mendelian genetics typically one or only a few traits are followed from generation to generation with inheritance patterns providing inferences as to whether the various alleles involved display dominant versus recessive characters.

Mendelian Genetics

Figure legend: The basic steps associated with the practice of Mendelian genetics. Note the prominence of controlled matings (crosses or ×) as well as determinations of offspring phenotypic ratios.

See, by contrast, the chromosomal theory of inheritance or molecular genetics, both of which are different from but otherwise consistent with Mendelian genetics. See also reverse genetics, DNA sequencing, genomics, etc.

Mendelian Genetics

Figure legend: Basic hints for solving Mendelian genetics problems.

The ideas of Mendelian genetics are much more easily appreciation based on actual experiments or, instead, in terms of problem sets, than they may be understood in more general or theoretical terms. Thus, starting with parents whose phenotypes are suggestive of particular underlying genotypes, one studies the prevalence of phenotypes among progeny to infer actual genotypes. 3:1 ratios of phenotypes among progeny organisms in particular are suggestive of dominance-recessive relationships among those alleles found at a given locus.

The following video discusses of Mendelian genetics featuring using Punnett squares:

This video considers both the multiplication rule and addition rule from probability theory, and then applies both to simple Mendelian Genetics problems: Video

The following video considers the various situations associated with Mendelian genetics as a applied to circumstances in which more than one locus is followed: