For a dihybrid cross, we ask students to predict the [F.
Mathematical concept in dihybrid tests for predicting phenotypes of seeds.
A dihybrid cross involves inheritance patterns for two traits considered simultaneously, a trihybrid cross involves three simultaneous traits, and so on.
Using the formula for figuring the possible combinations in a dihybrid cross, we can see that there are two or four possible combinations of alleles going to different gametes.
Any other classification would not provide a good fit to either monohybrid or dihybrid
cross A cross between parents that differ genetically in two or more independently inherited characteristics.
Four possible exercises are presented: two versions of a dihybrid
testcross and two versions of a three-point testcross.
Pamela A Marshall, in her article "Mapping Linked Genes in Drosophila melanogaster Using Data from the F2 Generation of a Dihybrid
2] seeds analysed for fatty acid content was usually too small to provide a meaningful interpretation of dihybrid
However, most genetics investigations with Drosophila analyze offspring patterns of the F2 generation of dihybrid
crosses to determine that genes are linked but do not calculate the map units between the linked genes (College Board, 2001; Mertens & Hammersmith, 2007; Scott, 2001).
Chi-square was used to test the data for goodness-of-fit to the monogenic ratios and the dihybrid
While Punnett squares are a useful device for determining the outcome of genetic crosses, they can become cumbersome for dihybrid
or trihybrid crosses.
The fruit fly cross is a dihybrid
cross involving two traits, each trait encoded by a single gene, each gene being represented by two alleles in that specific cross.
National Association of Biology Teachers (1994) and National Academy of Sciences (1998) offer activities or suggestions for using fruit flies, "red wiggler" worms, bacteria, fungi, plant proteins, and dihybrid
crosses of plants.
After learning about meiosis, including the random metaphase alignment of chromosomes, monohybrid crosses, use of Punnett squares, and Gregor Mendel's Theory of Segregation, introduce students to dihybrid
crosses involving two independently assorting genes.