Polydactyly is an inherited condition in which a person has extra fingers or toes. It is caused by a dominant allele of a gene. This means it can be passed on by just one parent if they have the disorder.
In this manner, what determines whether an allele is dominant or recessive?
Tay-Sachs disease is an autosomal recessive genetic disease that causes nervous system breakdown and death. What determines whether an allele is dominant, recessive, or codominant? protein to function, then the normal allele is dominant. If both alleles contribute to the phenotype, they are codominant.
Are alleles always dominant or recessive?
An allele that is always expressed is called a dominant allele. Any allele that is not expressed, unless there are two copies of it (=homozygous), is called a recessive allele 3. Usually a recessive allele is an inactive version of a gene.
Which allele is dominant?
The first allele is dominant and the second allele is recessive. For genes on an autosome (any chromosome other than a sex chromosome), the alleles and their associated traits are autosomal dominant or autosomal recessive. Dominance is a key concept in Mendelian inheritance and classical genetics.