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How many dominant alleles are required in a genotype to show the dominant phenotype?
Wiki User
∙ 11y ago
If the allele is dominant, you only need one copy for it to be expressed in the phenotype (you have TWO alleles for each trait) If the allele is dominant, you only need one copy for it to be expressed in the phenotype (you have TWO alleles for each trait)
Wiki User
∙ 15y ago
Wiki User
∙ 12y agoOnly one because if you put a dominant allele with a recessive allele the dominant allele will always show up no matter what. For example if you breed a Male Homozygous black lab with a Female Homozygous blond lab the black will show up in all of the dogs, because the male only has the dominant trait and passes it on to all of the pups.
Wiki User
∙ 12y agoevery thing has two allele traits, if you are dominant or recessive for a trait is determined by your alleles. there are two types of alleles, dominant and recessive. The trait in an organism is determined by the organism's parents. To find whether the organism, in this case a person, has a dominant or recessive trait you can use a punnent square. In science, a dominant trait is indicated by a capital letter (A) and a recessive trait is a lowercase letter (a).
Now, if one parent is homozygous, the two traits the parent has is the same, thus the prefix, homo. homozygous dominant (A,A) homozygous recessive (a,a). But that parent can be heterozygous, or having a dominant and recessive trait (A,a) a dominant trait will ALWAYS over shadow a recessive trait, so if you have one dominant allele, you are dominant for that trait. Now using a punnent square:
Parent one: Homozygous recessive (a,a)
Parent two: Heterozygous (A,a)
punnent square
a a
A A,a A,a
a a,a a,a
the chance of the offspring being dominant for this trait is 50% and the chance of the offspring having a recessive trait 50%
thus you only need one dominant allele for this trait to be expresses
Wiki User
∙ 12y agoone, but usually there is a reccesive gene too, but the dominant is still taking control. Lets say you have a dominant R for red hair, and a recesive r for othes. You will still have red hair because that dominant took over and now your gene is Rr.
Wiki User
∙ 14y ago4
Wiki User
∙ 11y agoOne.
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What phenotype is produced by AB genotype?
The genotype AA represents a homozygous dominant genotype. The capital letter "A" represents the dominant allele, while the lowercase letter "a" would represent the recessive allele. If both dominant alleles are present in a genotype (homozygous dominant) then the phenotype is "A" phenotype. If one dominant allele and one recessive allele are present (heterozygous dominant) then the phenotype is "A". Finally, if both recessive alleles "a" are present (homozygous recessive) then the phenotype is "a". Therefore, the answer to your question is the genotype AA would result in an "A" phenotype because the genotype is homozygous dominant.
What is an individual with genotype AAA described as?
An Aa genotype can result in the same phenotype as either an AA or AA genotype, if one of the alleles acts in a dominant fashion. If the A allele is dominant over the a allele, then the phenotype of a heterozygous (Aa) individual will be the same as the phenotype of a homozygous dominant (AA) individual.
If about 50 percent of the offspring have the dominant phenotype and 50 percent have the recessive phenotype what are the genotype of the parents?
If the phenotype is recessive then the genotype must be dd.
What is the differences between homozygous dominant and homozygous recessive and heterozygous?
A homozygous dominant genotype means that both alleles for a trait are dominant. A heterozygous genotype means that one allele is dominant and the other is recessive. A heterozygous genotype will express the dominant phenotype, not the recessive phenotype.
How is incomplete dominance expressed in phenotype?
In complete dominance, only one allele in the genotype is seen in the phenotype. In codominance, both alleles in the genotype are seen in the phenotype. In incomplete dominance, a mixture of the alleles in the genotype is seen in the phenotype.
What phenotype is produced by AB genotype?
The genotype AA represents a homozygous dominant genotype. The capital letter "A" represents the dominant allele, while the lowercase letter "a" would represent the recessive allele. If both dominant alleles are present in a genotype (homozygous dominant) then the phenotype is "A" phenotype. If one dominant allele and one recessive allele are present (heterozygous dominant) then the phenotype is "A". Finally, if both recessive alleles "a" are present (homozygous recessive) then the phenotype is "a". Therefore, the answer to your question is the genotype AA would result in an "A" phenotype because the genotype is homozygous dominant.
What is an individual with genotype AAA described as?
An Aa genotype can result in the same phenotype as either an AA or AA genotype, if one of the alleles acts in a dominant fashion. If the A allele is dominant over the a allele, then the phenotype of a heterozygous (Aa) individual will be the same as the phenotype of a homozygous dominant (AA) individual.
Using the terms dominant recessive explain the difference between genotype and phenotype?
No, I think you have your terms confused.The terms "dominant" and "recessive" are applied to alleles of a genotype. A genotype is an expression (using upper- and lower-case letters) that shows what alleles an organism has for a particular locus. The two alleles (in most cases) inherited (one from mother and one from father) can either be dominant or recessive. The recessive allele is not fully expressed in the presence of the dominant allele and is only expressed when there are two recessive alleles. The genotype could be called "recessive" I suppose if the genotype is homozygous recessive. But remember that two recessive alleles as a genotype is only one possibility - in which case you can't say the "genotype is recessive".The phenotype is dependent on the genotype. If present, the dominant alleles (in simple Mendelian genetics) will determine the phenotype - what the organism's trait or characteristic is. The phenotype will never be what is coded by the recessive allele unless the genotype is two recessive alleles.
What are alleles and what are the two forms?
They are traits that are passed on from parent to offspring. There are also two types of alleles; Dominant and recessive.
Why do the genotype Pp and pP all have the same phenotype?
because they all have at least one dominant alleles.
Can two organisms have the same phenotype and a different genotype?
Yes,if one has two dominant alleles and other has a dominant and a recessive allele
How are codominant alleles and incompletely dominant similar?
Codominance and incomplete dominance can only exist if the genotype has heterozygous alleles.
In what alleles can be observed in the phenotype?
you mean phenotype, and its dominant alleles
If about 50 percent of the offspring have the dominant phenotype and 50 percent have the recessive phenotype what are the genotype of the parents?
If the phenotype is recessive then the genotype must be dd.
Is the phenotype which determine RH?
Genotype determines the rh phenotype. The two alleles for rh factor are rh+ (rh positive) and rh- (rh negative). The rh+ allele is dominant.
What is the differences between homozygous dominant and homozygous recessive and heterozygous?
A homozygous dominant genotype means that both alleles for a trait are dominant. A heterozygous genotype means that one allele is dominant and the other is recessive. A heterozygous genotype will express the dominant phenotype, not the recessive phenotype.
How is incomplete dominance expressed in phenotype?
In complete dominance, only one allele in the genotype is seen in the phenotype. In codominance, both alleles in the genotype are seen in the phenotype. In incomplete dominance, a mixture of the alleles in the genotype is seen in the phenotype.
