gen-briefly-explain-dominant-and-recessive-alleles-and-one-commo-aab4

Briefly explain dominant and recessive alleles and one common misconception about it.

## Dominant and Recessive Alleles **Dominant alleles** are versions of a gene that express their trait even when only one copy is present. **Recessive alleles** only express their trait when two copies are present (one from each parent). For example, if B = brown eyes (dominant) and b = blue eyes (recessive): - BB or Bb = brown eyes - bb = blue eyes ## Common Misconception **"Dominant alleles are more common in populations"** — This is FALSE. Dominance refers only to how alleles are *expressed* at the individual level, not how *frequent* they are in a population. Some recessive alleles are actually very common, while some dominant alleles are rare. For instance, having six fingers (polydactyly) is caused by a dominant allele, but it's quite rare. The frequency of an allele in a population depends on factors like natural selection, genetic drift, and mutation rates — not whether it's dominant or recessive.