This is called co-dominance. This is when 2 or more alleles are expressed at the same time. In other words they both affect the phenotype. In the example of human blood ABO type we have an allele for A = IA, B= Ib O=i
IAIb = AB blood type
IbIb = B blood type
Iai = A
IaIa = A bloody type
Ibi = B blood type
ii = O blood type
What is expressed when both alleles for a gene are equally expressed as in human blood type is known as "co-dominance".
We call this codominance.
co-dominance
codominance and multiple alleles
alleles that everyone has
The human ABO blood group system is a good example of multiple alleles. There are three alleles involved: IA, IB and IO. If a person inherits two IA alleles, or IA and IO, they will be group A. If they inherit two IB alleles, or IB and IO, they will be group B. If you inherit two IO alleles you will be group O.
The colour of wheat seeds, or skin colour are common examples used in text books.
The blood type in humans
co dominance
This is called co-dominance. This is when 2 or more alleles are expressed at the same time. In other words they both affect the phenotype. In the example of human blood ABO type we have an allele for A = IA, B= Ib O=iIAIb = AB blood typeIbIb = B blood typeIai = AIaIa = A bloody typeIbi = B blood typeii = O blood type
This is called co-dominance. This is when 2 or more alleles are expressed at the same time. In other words they both affect the phenotype. In the example of human blood ABO type we have an allele for A = IA, B= Ib O=iIAIb = AB blood typeIbIb = B blood typeIai = AIaIa = A bloody typeIbi = B blood typeii = O blood type
This is called co-dominance. This is when 2 or more alleles are expressed at the same time. In other words they both affect the phenotype. In the example of human blood ABO type we have an allele for A = IA, B= Ib O=iIAIb = AB blood typeIbIb = B blood typeIai = AIaIa = A bloody typeIbi = B blood typeii = O blood type
This is called co-dominance. This is when 2 or more alleles are expressed at the same time. In other words they both affect the phenotype. In the example of human blood ABO type we have an allele for A = IA, B= Ib O=iIAIb = AB blood typeIbIb = B blood typeIai = AIaIa = A bloody typeIbi = B blood typeii = O blood type
This is called co-dominance. This is when 2 or more alleles are expressed at the same time. In other words they both affect the phenotype. In the example of human blood ABO type we have an allele for A = IA, B= Ib O=iIAIb = AB blood typeIbIb = B blood typeIai = AIaIa = A bloody typeIbi = B blood typeii = O blood type
Human blood type is determined by codominant alleles.
It depends on what you mean by "both are expressed". In order for both alleles to be expressed, both alleles must be dominant alleles. If one allele is recessive, it will be masked. If you are talking about alleles that are co-dominant, then both alleles would be expressed together. Ex: Red x white = red and white flower If you are talking about incomplete dominance, then both alleles are seen as a blend of both in the offspring. Ex: red x white = pink flower If you are talking about multiple alleles (like in human blood typing), then you can see 2 alleles expressed together. Ex: Type A x Type B can produce AB blood type.
There are three alleles for blood type: IA=Blood type A IB=Blood type B i=Blood type O The alleles for blood type A and B are codominant so when someone contains the IA and IB alleles, their blood type is AB.
Co-dominant alleles are both expressed, because both are translated into RNA. One of the best examples of co-dominance is human A/B blood type. The thing that differentiates A and B blood types is the antigens found on the surface of the blood cells. A person with two alleles for A-type antigens will have only A-type antigens, and a person with two B-type alleles will have only B-type antigens. However, a person with one A-type allele and one B-type allele will have blood type AB. A third allele, O-type, has no antigens on the surface of blood cells, and so is only "expressed" in the phenotype if a person has two O-type alleles (and therefore no antigens on their blood cells.)
There are three alleles for human blood groups. A, B and O. A and B are codominant, so are expressed together when this genotype is formed. AB. O is recessive and does not expresse unless it is homozygous recessive in expresion. OO. If, say, AO is the expression then only A would be expressed.
A trait is generally expressed phenotypically. An allele is one of a pair alleles at the same locus...often referred to as a gene. An allele is present whether expressed or not. A single gene locus will have two alleles in an individual, but there may be more than 2 alleles for this locus in the population. General human blood groups are an example of this with A,B, O as the primary alleles and several other less common ones...(like M) present in the population.