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Dominant allele concept definition
Some human disorders are inherited. Polydactyly is an inherited disorder.
- A person with polydactyly has extra fingers or toes.
- Polydactyly is caused by a dominant allele.
What is a dominant allele?
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Marking points
- 1 Explains that a dominant allele is expressed with only one copy/in the heterozygote despite a recessive allele being present.
Full-mark answer
A dominant allele is expressed in the phenotype even when only one copy is present in a heterozygous individual.
Why this answer loses marks
It is the stronger allele.
Dominance is about expression when only one copy is present, not physical strength.