Table of Contents
Which genes are dominant?
Examples of Dominant Traits
- Dark hair is dominant over blonde or red hair.
- Curly hair is dominant over straight hair.
- Baldness is a dominant trait.
- Having a widow’s peak (a V-shaped hairline) is dominant over having a straight hairline.
- Freckles, cleft chin and dimples are all examples of a dominant trait.
Are some alleles dominant?
Different alleles can be dominant or recessive for different reasons. It all depends on the gene. Each copy is called an allele. The two alleles for a gene don’t need to be the same.
What are two dominant alleles called?
If both alleles are dominant, it is called codominance?. The resulting characteristic is due to both alleles being expressed equally. An example of this is the blood group AB which is the result of codominance of the A and B dominant alleles.
Are dominant alleles always the most common?
A widespread misconception is that traits due to dominant alleles are the most common in the population. While this is sometimes true, it is not always the case. For example, the allele for Huntington’s Disease is dominant, while the allele for not developing this disorder is recessive.
What does it mean if a trait or allele is dominant?
An allele is dominant if it masks the presence of other alleles. This means that if an organism has one allele of this type, it will show the characteristics of this trait.
How does an allele become dominant?
Dominance typically occurs when one of the two alleles is non-functional at the molecular level, that is, it is not transcribed or else does not produce a functional protein product. This can be the result of a mutation that alters the DNA sequence of the allele.
Is the dominant alleles always expressed in the phenotype?
The genotype is the collection of alleles that determine characteristics and can be expressed as a phenotype. A dominant allele is always expressed , even if one copy is present. Dominant alleles are represented by a capital letter, for example, A. The allele for brown eyes is dominant. You only need one copy of this allele to have brown eyes.