Definition
noun
(genetics) The filial generation comprised of offspring(s) resulting from a cross between two individuals from the first filial generation
Supplement
In genetics, a test cross is done in order to determine the pattern of a particular genotype based on the phenotype of the offspring arising from a cross. Gregor Mendel, the father of Genetics, was the first to make use of a test cross through his series of experiments on garden pea plants.
A particular example is a cross he performed between two garden pea plants, i.e. one plant producing purple flowers and another plant producing white flowers. These two plants comprise the parental generation (P-generation) and the first hybrid offspring from the parental cross comprise the first filial generation. In Gregor Mendel’s test cross, the F1 offspring produce purple flowers. When the F1 hybrids were allowed to mate, the offspring resulted in plants producing either purple or white flowers. The offspring from the F1 generation comprise the second filial generation (or F2 generation). By definition, the F2 generation is the result of a cross between two F1 individuals (from F1 generation). Based on Gregor Mendel’s experiments through three generations , a 3:1 ratio was manifested (i.e. for every three purple-flower-bearing plants there would be one white-flower-bearing plant). Mendel’s quantitative analysis of the F2 generation led him to conceiving the fundamental principles of heredity, i.e. Law of Segregation and Law of Independent Assortment.
Abbreviation / Acronym:
- F2 generation
See also:
