Although individual humans (and all diploid organisms) can only have two alleles for a given gene, multiple alleles may exist at the population level such that many combinations of two alleles are observed.
Why do we have 2 alleles?
Since diploid organisms have two copies of each chromosome, they have two of each gene. Since genes come in more than one version, an organism can have two of the same alleles of a gene, or two different alleles. This is important because alleles can be dominant, recessive, or codominant to each other.
What is a normal allele?
“Allele” is the word that we use to describe the alternative form or versions of a gene. People inherit one allele for each autosomal gene from each parent, and we tend to lump the alleles into categories. Typically, we call them either normal or wild-type alleles, or abnormal, or mutant alleles.
What are the 3 alleles for blood type?
The four main blood groups A, B, AB, and O are controlled by three alleles: A, B, and O. As humans are diploid, only two of these can be present in any one genotype. In other words, only two of these alleles are present at the same time in a person’s cell.
Who is known as the father of genetics?
Gregor Mendel. Gregor Mendel’s work in pea led to our understanding of the foundational principles of inheritance. The Father of Genetics. Like many great artists, the work of Gregor Mendel was not appreciated until after his death.
Where do alleles come from?
One allele for every gene in an organism is inherited from each of that organism’s parents. In some cases, both parents provide the same allele of a given gene, and the offspring is referred to as homozygous (“homo” meaning “same”) for that allele.