A cross following two genes at once, giving a 9:3:3:1 phenotype ratio when genes assort independently.
Two heterozygous parents (RrYy) make four gamete types in equal ratio, creating 16 combinations and a 9:3:3:1 ratio of phenotypes. A test cross of RrYy with rryy gives 1:1:1:1.
Deviations from the expected ratio suggest linkage or epistasis.
A cross following two genes at once, giving a 9:3:3:1 phenotype ratio when genes assort independently.
Dihybrid Cross is one of the 54 topics in Genetics. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Monohybrid Cross, Law of Independent Assortment, Epistasis.
Mendel's round yellow and wrinkled green peas gave about 315:108:101:32.
Work through the Beginner topics in Genetics first, such as Heredity, Gene, Allele, then return to Dihybrid Cross. Intermediate topics assume the Beginner vocabulary.
The closest topics to Dihybrid Cross are Monohybrid Cross, Law of Independent Assortment, Epistasis, Test Cross. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Dihybrid Cross. To practise the whole of Genetics, use the Genetics quiz.
Dihybrid Cross: A cross following two genes at once, giving a 9:3:3:1 phenotype ratio when genes assort independently. Monohybrid Cross: A cross following one gene with two alleles, giving a 3:1 phenotype ratio in the F2 generation. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Monohybrid Cross and explain the difference aloud. Finally, take the Genetics quiz and come back to this page for any question you miss.
A cross following one gene with two alleles, giving a 3:1 phenotype ratio in the F2 generation.
🧬 GeneticsAlleles of different genes are distributed to gametes independently when the genes lie on separate chromosomes.
🧬 GeneticsOne gene masks or modifies the expression of another gene at a different locus.
🧬 GeneticsCrossing an unknown dominant phenotype with a homozygous recessive to reveal its genotype.
🧬 Genetics