Colorblindness is a sex-linked trait carried on the X chromosome. Males have an X and a Y chromosome (XY) and females have two X chromosomes (XX). Normal vision is dominant over colorblindness.
This means that the man must have an allele for normal vision on his only X chromosome. This also means that the woman must have two colorblind alleles on both of her X chromosomes.
If we use a capital 'B' to represent normal vision and a lowercase 'b' to represent colorblindness, the genotype of the male would be XBY, and the genotype of the female would be XbXb.
Now that we know the genotypes, setting up the Punnett square should be easy. Here is a direct image link to the Punnett square: http://i.imgur.com/gDfUv.png
This Punnett square tells us that there is a 50% chance of having a female that has normal vision and a 50% chance of having a colorblind male.
Yes.
The phenotypic ratio will be 1:3.his son will be color blind.
All the sons would be color-blind and none of the daughters are color-blind.
The colorblind woman can pass the allele to all her children including sons and daughters but the daugthers will only be carriers for the trait whereas the sons will produce the trait. In order for the daughter to express the trait they would need the allele not only from the mother but from the father also. I just took an exam on this and got it right.
Women can not be colorblind, only men. For questions like these a punnett square is useful. Men can not carry the colorblind trait, but women can. I know this is kind of confusing. When a carrier ( a woman with the color blind trait) has children with a man ( color blind or not) her kids will have 50% chance of having that trait. If its a girl, she will be the carrier. If its a boy, he will have the colorblind trait. SO TO ANSWER YOUR QUESTION: Theoreticaly, 1 of the daughters will be the carrier, and the son will have a 50% chance of being colorblind. Women can be colorblind, its just rare. About every 6400 women one is colour blind and with men, every 80 men 1 is colour blind.
50%. 1 of the two male offspring will definately be color blind. Do a punnett square with the father having normal vision and the mother being a carrier.
It is not impact our vision.
Color blindness typically does not affect life expectancy. It is a hereditary condition that primarily impacts the way individuals perceive colors. People with color blindness can lead normal, healthy lives without any impact on their overall life expectancy.
Assuming that the man who has normal vision is homozygous for normal vision, the couple's daughter will either be homozygous for normal vision or heterozygous (normal vision but carrier for color blindness) for normal vision. In light of this, the couple's daughter will not be color blind.
The probability is 0 (but the daughter will be a carrier of the color blind gene). This is because the gene dictating whether someone is color blind or not is linked to the X chromosome (and not the Y). The color blind gene is a recessive gene whilst the normal color vision gene is a dominant gene. Hence if a girl (XX) has one normal vision gene (from one parent) and one color blind gene (from the other parent), her normal vision gene will be dominant to the recessive color blind gene and hence she will have normal vision (but she will be a carrier of the color blind gene). If both her parents contribute the recessive color blind gene to her, then she will be color blind. For a woman (XX) to be color blind, she needs to be have both genes to be recessive (ie where there is no dominant normal color vision gene to dominate). For a man (XY), as long as the X gene contributed by his mother is a color blind gene, he will be color blind because he has no other X chromosome where a dominant normal color gene could reside. Hence, to answer the question, a man with normal color vision (XY, with a dominant normal color vision X gene since the gene can't be the recessive color blind gene otherwise he will be colorblind) and a colorblind woman (XX, both recessive color blind genes), will each contribute an X each the child. The man will contribute his only X chromosome which carries the normal color vision X gene and the woman can only contribute a recessive color blind gene. The man's normal color vision X gene will be dominant, and hence the daughter will definitely have normal vision (despite being a carrier).
Yes.
No they will produce a child who is colour blind.
The phenotypic ratio will be 1:3.his son will be color blind.
20/200 means you can only see at 20 feet what a person with normal vision can see at 200 feet. Therefore you would be legally blind.
It's not normal to be blind unless your eye is swollen shut. But it's common to have blurred vision.
There is a range in blindness from visulally impaired through legally blind to totally blind. Legally blind in most jurisdictions is a range of vision where the person can only see at 20 feet wwhat a normal sighted person can see at 100 feet.
Blind is when a person can't seeAnswer:There is a range in blindness from visulally impaired through legally blind to totally blind. Legally blind in most jurisdictions is a range of vision where the person can only see at 20 feet wwhat a normal sighted person can see at 100 feet.