males have only one X chromosomes
In humans males sex is determined by the presence of the Y chromosome. This is a very short compared to the X chromosome with which it is pair. Therefore if there is a genetic defect on the X chromosome then it cannot be masked by a beneficial one on the Y as it is simply not there.
X linked recessive disorders are most commonly found in males as males have an X and a Y chromosome (XY) whereas females have XX. This means that if a female contains one of the recessive genes (Xx) they remain unaffected by the condition as they still have the dominant normal gene, males on the other hand only have one x chromosome so are more liable to get the disorder.
A female who is unaffected by the disorder but has the recessive gene (Xx) is called a carrier and could potentially pass on the disorder to her offspring.
Males are more often affected by x linked disorders because the y chromosome offers less genetic protection from much of the genetic material passed from the mother to the male offspring.
I you imagine the Xy combination more like a capital X and a lower case y for relative size you can better visualize the difference in genetic material contained on the y vs. X chromosomes (this is illustrative only). If the negative genetic trait is passed on from the mother to the son on the part of the X chromosome that has no corresponding allele on the y from the father the genetic disorder will manifest in the son.
If the father does not have the characteristic and the mother is a carrier, she will pass her affected X chromosome to 50% of her daughters but all will be carriers and not be affected by the recessive disorder due to the presence of the fathers X chromosome.
50% of her sons will have the disorder and 50% will not have the recessive allele.
females may mask recessive genes with dominant genes for the disorder.
Because females have two dominant genes for the disorder
males have only one X chromosomes
For a recessive sex-linked trait to manifest in women it would have to be in double dose (XaXa) while for men in single dose (XaY). Women carriers would have one of each but would not be affected (XAXa). Knowing this it's quite easy to spot pedigrees where this kind of inheritance occures.Heterozygote mothers (gene carrier) can have sons that are affected (50% chance);Affected mothers have only affected sons (100%);No first generation daughter of an heterozygote mother will be affected but there is a 50% chance that she is a carrier;Affected fathers with normal mothers will have zero sons that are affected but all their daughters will be carriers;
Several genetic disorders are caused by genes on the X chromosomes.
the allele for colorblindness is recessive and located on the X chromosomes
If the trait is recessive and on the male chromosome (Y), then it is impossible for females to get it since they do not possess a Y chromosome. If you meant a recessive sex-linked trait on the X chromosome (like male pattern baldness), then males are still more likely to get it since they only receive one X chromosome and if it is affected they would automatically have the trait (whereas females have 2 copies and would only have the trait if both parents passed on chromosomes containing the recessive allele.) Females can be carriers, though. If they are a carrier (have one affected X chromosome) for the trait then their male children would have a 50% chance of inheriting the trait and their female children would have a 50% chance of becoming carriers.
Females carry two X chromosomes; males only carry one. A female carrier carries a defective recessive allele for a gene on the X chromosome. Thus, the female will not be affected because she still has a copy of the dominant allele. However, if she has any male children, that child will be affected because males inherit their X chromosome from their mothers.
All forms of NPD are inherited autosomal recessive disorders, requiring the presence of an inherited genetic mutation in only one copy of the gene responsible for the disease. Both males and females are affected equally.
males have only one X chromosomes
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.
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.
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.
Caucasian females between the ages of 15 and 26. However, all races and age groups are affected.
females
This genetic condition is likely an autosomal recessive trait since it occurs with equal frequency in males and females. If neither parent is affected, it suggests that both parents are carriers of the condition. In order for a child to be affected, they would need to inherit two copies of the recessive allele, one from each carrier parent.
If you are a carrier of a sex-linked genetic disorder, you will carry that disorder based on your sex hormones, because they influence the appearance of the trait. A person who carries the trait will have the disease but may not show it. ---- Sex-linked disorders are genetic disorders linked directly to a human's chromosomes. In the case of chromosomes, females (XX) give an X chromosome to their offspring. Males (XY) can give either an X or a Y chromosome to their offspring. Because only males can have a Y chromosome, sex-linked disorders usually occur in males.
Males only have one copy of the X chromosome
About 90% of eating disorders affect 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.