What does the law of dominance state?

The law of dominance is a key principle in genetics, particularly in the study of inheritance patterns. It was first introduced by Gregor Mendel through his experiments with pea plants.

Definition of the Law of Dominance

This law states that when two different alleles for a trait are present in an organism, one allele can mask the expression of the other. The allele that is expressed is termed the dominant allele, while the one that is hidden is called the recessive allele.

Key Points to Remember

• Dominant Allele: This allele's traits are visible in the organism.
• Recessive Allele: This allele's traits are not expressed when a dominant allele is present.
• Homozygous vs. Heterozygous: An organism with two identical alleles for a trait is homozygous, while one with two different alleles is heterozygous.

Examples in Nature

For instance, in pea plants, the allele for purple flowers is dominant over the allele for white flowers. Therefore, a plant with one purple allele and one white allele will have purple flowers.

Importance in Genetics

The law of dominance helps explain how traits are passed from parents to offspring and is fundamental in predicting the outcomes of genetic crosses.