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Why are all x-linked alleles expressed in males even if they are recessive?
Wiki User
∙ 14y ago
X-linked are not recessive nor dominant. X-linked just do not show. On the sex-linked chromosomes the Y chromosome of the X-Y pair dominates the trait whether its recessive or dominant!
Actually, all x-linked alleles are expressed because males only have one x-chromosome, so whatever is there, dominant or recessive, is expressed.
Wiki User
∙ 14y ago
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Under what condition is a single recessive allele expressed in a male?
Recessive alleles are expressed if there is no dominant allele (of the same gene) present. This can be for two reasons, because the other allele is also recessive, or because there is no other allele (such as X-linked genes, which males only have one copy of).
Is colorblindness a dominant or recessive trait?
Color blindness is an inherited trait that can be passed on through reproduction but it has some peculiarities. It is recessive and not very prevalent in the gene pool. Because of this, color blindness does not appear very often in the population. In addition, it is a sex-linked gene on the X chromosome. Thus males only have one gene to express color vision. If it happens to be the recessive allele, then males are color blind. Females, on the other hand, must have both alleles recessive in order to be color blind.source: ciese.org/curriculum/genproj/activity35.html
Traits controlled by recessive alleles on the x chromosome are more common in males than in females explain why?
Males only have one X chromosome, so even if the gene on that chromosome is recessive there is no other gene that could dominate it. Females have two X chromosomes, so if the gene on that chromosome is recessive there is still a chance that the gene on the other chromosome could be dominate and override it.
Under what condition can a female acquire an X recessive disorder?
Both X chromosomes must carry the recessive trait. Since males only have one X chromosome, it is much easier for males to have the recessive phenotype. Put another way, a female would have to receive an X chromosome with the recessive gene from both parents, which would mean the father already displays the recessive disorder.
Which genotype would result in an individual with the dominant phenotype?
In classic genetics: AA or Aa for autosomal dominance; for sex-linked dominance, females will need XX or Xx, while males will need Xy It gets more complicated with epistasis and other factors that modulate the genes.
Why are x linked alleles expressed in males even if they are recessive?
X-linked are not recessive nor dominant. X-linked just do not show. On the sex-linked chromosomes the Y chromosome of the X-Y pair dominates the trait whether its recessive or dominant!Actually, all x-linked alleles are expressed because males only have one x-chromosome, so whatever is there, dominant or recessive, is expressed.
Under what condition is a single recessive allele expressed in a male?
Recessive alleles are expressed if there is no dominant allele (of the same gene) present. This can be for two reasons, because the other allele is also recessive, or because there is no other allele (such as X-linked genes, which males only have one copy of).
Most copies of harmful recessive alleles are carried by?
individuals that are heterozygous for alleles
Why is a son who receives the allele for color blindness from his mother always colorblind?
Being Colorblind means you recieved 2 recessive alleles from you parents. So that means the mother and father must of had 2 recessive alleles. Also Colorblindness is more common in males.
What evidence is there that the long and round alleles did not become blended?
A number of genetic disorders are caused when an individual inherits two recessive alleles for a single-gene trait. Recessive genetic disorders include Albinism, Cystic Fibrosis, Galactosemia, Phenylketonuria (PKU), and Tay-Sachs Disease. Other disorders are also due to recessive alleles, but because the gene locus is located on the X chromosome, so that males have only one copy (that is, they are hemizygous), they are more frequent in males than in females.
Is colorblindness a dominant or recessive trait?
Color blindness is an inherited trait that can be passed on through reproduction but it has some peculiarities. It is recessive and not very prevalent in the gene pool. Because of this, color blindness does not appear very often in the population. In addition, it is a sex-linked gene on the X chromosome. Thus males only have one gene to express color vision. If it happens to be the recessive allele, then males are color blind. Females, on the other hand, must have both alleles recessive in order to be color blind.source: ciese.org/curriculum/genproj/activity35.html
What evidence is there that the long and round did not become blended?
A number of genetic disorders are caused when an individual inherits two recessive alleles for a single-gene trait. Recessive genetic disorders include Albinism, Cystic Fibrosis, Galactosemia, Phenylketonuria (PKU), and Tay-Sachs Disease. Other disorders are also due to recessive alleles, but because the gene locus is located on the X chromosome, so that males have only one copy (that is, they are hemizygous), they are more frequent in males than in females.
Why are traits controlled by recessive alleles on the X chromosome are more common in males than in females?
Males only have one X chromosome, so even if the gene on that chromosome is recessive there is no other gene that could dominate it. Females have two X chromosomes, so if the gene on that chromosome is recessive there is still a chance that the gene on the other chromosome could be dominate and override it.
What evidence is there that the long round allels did not become blended?
A number of genetic disorders are caused when an individual inherits two recessive alleles for a single-gene trait. Recessive genetic disorders include Albinism, Cystic Fibrosis, Galactosemia, Phenylketonuria (PKU), and Tay-Sachs Disease. Other disorders are also due to recessive alleles, but because the gene locus is located on the X chromosome, so that males have only one copy (that is, they are hemizygous), they are more frequent in males than in females.
Why are sex linked recessive disorders such as hemophilia most often seen in males and rarely seen in females?
The recessive genes are present on the X-chromosome. Female chromosome has another X-chromosome, which is dominant and masks the defective gene, and it is quite rare that both the chromosomes have recessive alleles. But, in males, the Y-chromosome has nothing to over mask the defective gene and the abnormality shows up in the form of the disease.
Why do x linked conditions appear more frequently in males than females?
Because males have an X and Y chromosome. If the trait is X-linked (recessive), there is nothing to mask the expression. On the other hand if a woman has an x-linked recessive allele and a dominant one, the dominant trait is the one that will be expressed.
What does alleles always come in?
Alleles are generally inherited in pairs, except for alleles on the X and Y sex chromosomes in males.
