What is the Difference Between Dominant and Recessive Alleles?
🆚 Go to Comparative Table 🆚The difference between dominant and recessive alleles lies in their interaction and expression in an organism. Here are the key differences:
- Expression: A dominant allele shows its effect even if the individual has only one copy of the allele, while a recessive allele only shows its effect if the individual has two copies of the allele.
- Inheritance: For a dominant allele to be expressed, only one copy of the allele is needed, which can come from either parent. In contrast, for a recessive allele to be expressed, the individual must have two copies, one from each parent.
- Dominance Relationship: An allele is considered dominant when it effectively overrules the other recessive allele. For example, the allele for brown eyes (B) is dominant over the allele for blue eyes (b). If an individual has one allele for brown eyes and one allele for blue eyes (Bb), their eyes will be brown.
- Notation: Dominant alleles are denoted by a capital letter, while recessive alleles are denoted by a small letter.
Some examples of dominant and recessive traits include eye color and blood groups. The allele for brown eyes (B) is dominant over the allele for blue eyes (b), so if a person has one allele for brown eyes and one for blue eyes, their eyes will be brown. In the case of blood groups, the A and B alleles are co-dominant, meaning they are both equally ‘strong’ and produce a combined physical trait when present together.
Comparative Table: Dominant vs Recessive Alleles
The difference between dominant and recessive alleles can be summarized in the following table:
Dominant Alleles | Recessive Alleles |
---|---|
Produce a dominant phenotype even when only one copy is present | Produce a recessive phenotype only when two copies are present |
Express their effect even if the individual has only one copy of the allele | Express their effect only if the individual has two copies of the allele |
Denoted by a capital letter | Denoted by a small letter |
For example, the allele for brown eyes is dominant, so you only need one copy of the 'brown eye' allele to have brown eyes. On the other hand, the allele for blue eyes is recessive, so you need two copies of the 'blue eye' allele to have blue eyes.
- Dominant vs Recessive
- X Linked Dominant vs X Linked Recessive
- Dominant vs Recessive Epistasis
- Codominance vs Multiple Alleles
- Autosomal Dominant vs Autosomal Recessive Disorders
- Gene vs Allele
- Allele vs Trait
- Allele vs Genotype
- Dominance vs Codominance
- Multiple Alleles vs Lethal Alleles
- Homozygous vs Heterozygous
- Codominance vs Incomplete Dominance
- Allele vs Locus
- Allelic vs Non allelic Gene
- Dominance vs Epistasis
- Heterozygous vs Homozygous Individuals
- Homozygous vs Hemizygous
- Multiple Alleles vs Polygenic Traits
- Haploinsufficiency vs Dominant Negative