In Mendelian genetics, what does the term 'dominant' refer to?

In Mendelian genetics, what does the term 'dominant' refer to?

• A. A trait that is expressed when at least one allele is present
• B. A trait that is expressed only when two alleles are present
• C. A trait that is never expressed
• D. A trait that is only expressed in female offspring

Answer: (A)

In Mendelian genetics, the term 'dominant' refers to a trait that is expressed when at least one allele for that trait is present. This means that if an individual carries one dominant allele, the associated trait will be observed in their phenotype, regardless of the presence of any recessive alleles. For example, if a flower has a dominant allele for purple color and a recessive allele for white color, the flower will be purple. This characteristic of dominant traits is a fundamental concept in genetics, as it explains how traits are passed down through generations and how they can appear in offspring even when only one parent contributes the dominant allele. Understanding the nature of dominance is crucial for predicting genetic outcomes and analyzing inheritance patterns in traits.

In Mendelian genetics, the term 'dominant' refers to a trait that is expressed when at least one allele for that trait is present. This means that if an individual carries one dominant allele, the associated trait will be observed in their phenotype, regardless of the presence of any recessive alleles. For example, if a flower has a dominant allele for purple color and a recessive allele for white color, the flower will be purple.

This characteristic of dominant traits is a fundamental concept in genetics, as it explains how traits are passed down through generations and how they can appear in offspring even when only one parent contributes the dominant allele. Understanding the nature of dominance is crucial for predicting genetic outcomes and analyzing inheritance patterns in traits.