What is a dominant allele written as?
The dominant allele is by convention written with a capital (upper case) letter. Recessive: In the heterozygous genotype, the expression of one allele is sometimes masked by another. The allele which is masked is said to be recessive. The recessive allele is by convention written with a lower case letter.
Which is dominant allele A or B?
With eye color, for instance, “B” stands for a brown allele and “b” stands for a blue allele. An organism with two dominant alleles for a trait is said to have a homozygous dominant genotype. Using the eye color example, this genotype is written BB.
What letter represents the dominant gene?
A capital letter represents the dominant form of a gene (allele) and a lowercase letter is the abbreviation for the recessive form of the gene (allele).
How do we write the symbols for dominant traits?
The capital “I” letter indicates it is dominant to “i”. The superscript A and B for the codominant alleles indicate the dominant alleles are different from each other. Superscripts can be symbols, a single letter, or many letters.
How do you write homozygous dominant?
When a particular gene has identical alleles (versions) of chromosomes inherited from both parents, the gene is homozygous. A homozygous trait is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.
Can alleles be dominant?
It is a strictly relative effect between two alleles of a given gene of any function; one allele can be dominant over a second allele of the same gene, recessive to a third and co-dominant with a fourth. Additionally, one allele may be dominant for one trait but not others.
Is BB heterozygous or homozygous?
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). A bull with two alleles for a black coat is homozygous (BB).
Is SS heterozygous or homozygous?
Specifically, heterozygous (Ss) individuals express both normal and sickle hemoglobin, so they have a mixture of normal and sickle red blood cells. In most situations, individuals who are heterozygous for sickle-cell anemia are phenotypically normal. Under these circumstances, sickle-cell disease is a recessive trait.