Alleles

Alleles are different forms of a gene that can occupy the same position, or locus, on a chromosome. They can be dominant or recessive, and they determine specific traits, such as hair color, eye color, and blood type, in an organism.

Types of Alleles

There are two main types of alleles:

1. Dominant Allele: A dominant allele will always be expressed if it is present. It is represented by a capital letter (e.g., A).
2. Recessive Allele: A recessive allele will only be expressed if the dominant allele is not present. It is represented by a lowercase letter (e.g., a).

Genotype and Phenotype

An organism's genotype refers to the specific combination of alleles it has for a particular trait, while its phenotype refers to the physical expression of those alleles.

Study Guide

1. What are alleles?
2. What are the two main types of alleles?
3. How are dominant alleles represented?
4. How are recessive alleles represented?
5. What is the difference between genotype and phenotype?

Understanding alleles is important in the study of genetics and heredity, as they play a crucial role in determining the traits of living organisms.