Question

1. explain the difference between a dominant allele and a recessive allele.

Explanation:

A dominant allele is one that expresses its trait (phenotype) even when paired with a different allele (heterozygous, e.g., \( Aa \), where \( A \) is dominant). A recessive allele only shows its trait when paired with another recessive allele (homozygous recessive, e.g., \( aa \)); in heterozygous conditions (\( Aa \)), its trait is masked by the dominant allele. For example, in pea plants, the allele for tall height (\( T \)) is dominant over the allele for short height (\( t \))—\( TT \) and \( Tt \) plants are tall, while \( tt \) plants are short.

Answer:

• Dominant allele: Expressed in heterozygous (\( Aa \)) or homozygous (\( AA \)) state, masks recessive allele’s trait.
• Recessive allele: Expressed only in homozygous (\( aa \)) state, masked by dominant allele in heterozygous (\( Aa \)) state.