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Why are x linked alleles expressed in males even if they are recessive?
Wiki User
∙ 7y 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.
Vern Kovacek
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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).
Most copies of harmful recessive alleles are carried by?
individuals that are heterozygous for alleles
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
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 is a trait that is passed from parent to child on the X chromosome called?
Recessive traits on X chromosome are expressed in males because they have only one copy of X chromosome. If they have any recessive gene it will be expressed. In female both the genes should be recessive then only the recessive character will be expressed.
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.
Is Colourblindness in males is an example of incomplete dominance?
No, it is an example of sex-linked recessive inheritance.
If a daughter expresses an x-linked recessive gene she inherited the trait from?
For a female to express an X linked recessive gene, she must have inherited it from both parents. Every female (without disease) has two X chromosomes: XX, while males have an X and a Y: XY. A recessive gene is one that will not be expressed if there is a copy of the dominant gene present. sex linked genes have their own special set of rules because the sex chromosomes are the only ones which vary by presence or absence between different people. Because a male only has one X chromsome, he will express all the genes on that chromosome; this can be used to determine if a gene is sex linked and recessive/dominant. A recessive gene will not be expressed if there is a dominant gene for that allele present. This means that if a female (XX) is expressing an x-linked recessive trait, she must have two recessive genes for that trait; therefore she inherited the trait from both parents.
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 is the difference between recessive disorders and dominant disorders?
A sex linked dominant trait could be on the X chromosome of either parent and the phenotype of any individual carrier would be that of the dominant trait. A father with the dominant characteristic on his single X chromosome would produce daughters that are 100% carriers and would not pass the characteristic on to his sons. A mother who is a dominant X linked carrier would pass the dominant characteristic on to half hersons and half her daughters all of which would show the trait phenotypically. A sex linked recessive father would produce 100% carrier daughters. His sons would not get the recessive allele from him. A sex linked recessive carrier (heterozygous) mother would pass the trait on to 50% of her children and 50% of her sons would show the recessive trait genetics.
Why are sex linked recessive conditions more likely in males then females?
Because females have TWO X chromosomes. Males only have one. that means if the recessive gene is on the X chromosome it becomes evident phenotypically.
Why are males most likely to express a sex linked recessive trait?
Males have only one X chromosome, so a recessive X-linked trait will be displayed in the phenotype [visible on the outside]. Females have two X chromosomes, so both of the chromosomes must have the trait for it to be displayed on the phenotype.
