More than two allelic forms of a gene exist in a population, like the ABO blood group alleles.
ABO blood group: IA and IB are dominant over i, but codominant to each other, giving genotypes AA, AO, BB, BO, AB and OO. Rabbits have four alleles for coat colour.
Each individual still has only two alleles.
More than two allelic forms of a gene exist in a population, like the ABO blood group alleles.
Multiple Alleles 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 Codominance, Allele, Mutations.
A type A mother and type B father could have an O child if both are heterozygous (IAi x IBi).
Work through the Beginner topics in Genetics first, such as Heredity, Gene, Allele, then return to Multiple Alleles. Intermediate topics assume the Beginner vocabulary.
The closest topics to Multiple Alleles are Codominance, Allele, Mutations, Sex Chromosomes. 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 Multiple Alleles. To practise the whole of Genetics, use the Genetics quiz.
Multiple Alleles: More than two allelic forms of a gene exist in a population, like the ABO blood group alleles. Codominance: Both alleles are fully expressed in the heterozygote, as in the AB blood type. 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 Codominance and explain the difference aloud. Finally, take the Genetics quiz and come back to this page for any question you miss.
Both alleles are fully expressed in the heterozygote, as in the AB blood type.
🧬 GeneticsOne of the alternative versions of a gene found at the same position on a chromosome.
🧬 GeneticsPermanent changes in the DNA sequence that can be harmless, harmful or occasionally beneficial.
🧬 GeneticsX and Y chromosomes determine biological sex in humans; XX is typically female and XY male.
🧬 Genetics