We mostly use letters as an abbreviation for alleles, B = black, b = red. An individual that contains two copies of the same allele for a specific gene is homozygous. An individual that contains two different alleles of a gene is heterozygous. A cow that has two alleles for a red coat is homozygous (bb).
Do the alleles have to be the same for each trait?
When genes mutate, they can take on multiple forms, with each form differing slightly in the sequence of their base DNA. These gene variants still code for the same trait (i.e. hair color), but they differ in how the trait is expressed (i.e. brown vs blonde hair). Different versions of the same gene are called alleles.
How do you write alleles?
Alleles may be designated by a single capital or lower case letter (e.g., L is the symbol of Lobe eye in Drosophila) or by two , three or more letter or letter/number combinations (Wr – Wrinkled, per – periodicity). Alleles may have superscripts (wa) or subscripts (A1) or both.
Are alleles always identical?
An individual’s genotype for that gene is the set of alleles it happens to possess. … An organism in which the two copies of the gene are identical — that is, have the same allele — is called homozygous for that gene. An organism which has two different alleles of the gene is called heterozygous.
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.
Which is the best example of an allele?
Frequency: The definition of alleles are pairs or series of genes on a chromosome that determine the hereditary characteristics. An example of an allele is the gene that determines hair color.
How many types of alleles are there?
An individual inherits two alleles for each gene, one from each parent. If the two alleles are the same, the individual is homozygous for that gene. If the alleles are different, the individual is heterozygous.