Dominant gene

📖 Full definition

A dominant gene imposes its expression over the recessive gene at the same chromosomal position. For visible traits (eye color, nose shape), many are partially dominant: they do not express in all-or-nothing but influence the phenotypic trajectory.

💡 Concrete example

The brown eye gene (B) is dominant over the blue eye gene (b). A Bb child will have brown eyes. To have blue eyes, the genotype must be bb (homozygous recessive).

🔄 Synonyms

dominant allele

🔗 See also

• Phenotype →
• Genotype →