What is a characteristic of an autosomal dominant trait?

What is a characteristic of an autosomal dominant trait?

• A. Two copies of the allele are required for expression
• B. Carriers exhibit the trait
• C. Only one copy of the dominant allele is needed for expression
• D. It can skip generations in family trees

Answer: (C)

An autosomal dominant trait is characterized by the fact that only one copy of the dominant allele is required for the trait to be expressed in an individual. This means that if an individual inherits just one copy of the dominant allele from one parent, they will display the trait regardless of the allele inherited from the other parent. This property leads to the trait appearing in every generation, as it does not require both alleles to express the dominant phenotype, which is a key distinguishing factor from traits that are autosomal recessive, where two copies of the recessive allele are necessary for expression. The presence of one dominant allele ensures that the associated trait is expressed in the phenotype, contributing to its transmission through generations. Understanding this aspect is crucial for analyzing inheritance patterns and predicting the likelihood of the trait appearing in offspring.

An autosomal dominant trait is characterized by the fact that only one copy of the dominant allele is required for the trait to be expressed in an individual. This means that if an individual inherits just one copy of the dominant allele from one parent, they will display the trait regardless of the allele inherited from the other parent. This property leads to the trait appearing in every generation, as it does not require both alleles to express the dominant phenotype, which is a key distinguishing factor from traits that are autosomal recessive, where two copies of the recessive allele are necessary for expression.

The presence of one dominant allele ensures that the associated trait is expressed in the phenotype, contributing to its transmission through generations. Understanding this aspect is crucial for analyzing inheritance patterns and predicting the likelihood of the trait appearing in offspring.