Here's a breakdown:
* Allele: An alternative form of a gene.
* Gene: A segment of DNA that codes for a specific trait.
* Trait: A characteristic or feature of an organism, such as eye color or hair color.
For example, let's say the gene for eye color has two alleles:
* B: Brown eyes
* b: Blue eyes
A person with the genotype Bb would be heterozygous for eye color, meaning they have one allele for brown eyes and one allele for blue eyes.
What happens in a heterozygous individual?
The way these alleles interact determines the individual's phenotype, which is the observable trait. There are two main possibilities:
* Dominant/Recessive inheritance: One allele (the dominant allele) masks the expression of the other (the recessive allele). In our eye color example, brown eyes are usually dominant, so a person with the genotype Bb would have brown eyes.
* Codominance: Both alleles are expressed equally, resulting in a combined phenotype. For example, if the alleles for flower color were red (R) and white (r) and codominant, a heterozygous plant (Rr) would have pink flowers.
In summary, having two different alleles for a trait means the individual is heterozygous, and the phenotype will be determined by how those alleles interact.
