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Is it true that if a man is colorblind his mother must have the allele for this disorder on at least one of her X chromosomes?
Yes, that is true. The male only needs to receive one defective copy, since a recessive gene becomes dominant when the other gene is missing -- and the Y chromosome generally cannot carry a healthy version of the gene. So most women who carry the gene are only carriers, since they usually have another X chromosome to balance it out. For women to get the typical forms of color blindness, they would have to get it from both parents, while men would only need to get it from the mother.
Now the rare form of colorblindness that impacts blue vision is not carried on the 23rd chromosomal pair, so everyone is equally likely to get it regardless of gender.
What else can I help you with?
If a man is colorblind his mother must have the allele for this disorder on at least one of her X chromosome?
True
What if Mary and her mother are both colorblind is Mary's father colorblind too?
If Mary's mother is colorblind, and therefore carries the colorblind gene on one of her X chromosomes, then Mary would inherit that gene as well. If Mary's father is colorblind, he would have to pass on his X chromosome with the colorblind gene to Mary, making her colorblind too. If only Mary's mother is colorblind, Mary's father is likely not colorblind.
Father isn't colorblind mother is a carrier--one son is colorblind but the other is not how?
It is called x-linked alleles. It is rare for a female to have color blindness because the allele must be passed from both parents. Males only need one allele to be color blind.With the equation, color blind female and non-color blind male reproduce. Each son has a 50% chance of developing the disorder.
A womens father is colorblind She marries a colorblind man Will there son or daughter be colorblind?
Colorblindness is an X-linked recessive disorder. This means girls (who have the sex chromosomes XX) must have a colorblind X from dad and a colorblind X from mom. Boys only need to have one colorblind X to be colorblind because they have sex chromosomes XY (and have only 1 X). If the dad has it, he has the colorblind X. If the daughter has it, she must have gotten her mom's colorblind X. If the mom is colorblind, then every child they have will be colorblind. If the mom is not colorblind, then she must be a carrier - she must have 1 normal X and 1 colorblind X. Mom is either colorblind (with 2 colorblind Xs) or she is a carrier. Dad is definitely colorblind.
Why is a son who receives the allele for color blindness from his mother always colorblind?
Color blindness is a sex-linked trait that is carried on the X chromosome. Since males inherit their single X chromosome from their mother, if the mother carries the allele for color blindness, her son will inherit it and be colorblind. Females need two copies of the allele to be colorblind, so they can be carriers without exhibiting the trait.
If a color blind man has a color blind daughter then the mother has to be color blind as well?
The father has to be colorblind for the daughter to be colorblind because both X chromosomes must have the colorblindness gene in females because the colorblind gene is recessive. If only the mother is color deficient, then she merely passes on the gene to one of the X chromosomes in a female. If both the mother and father are both colorblind, then both X chromosomes in the female are effected and the female is colorblind. There are two scenarios in which a daughter may be born colorblind. 1. The father is colorblind and the mother is a carrier of the colorblind gene. The daughter will be either colorblind or a carrier of the colorblind gene. 2. The father and mother are both colorblind. If this is the case, then all of the children will be born colorblind.
Why is a son who receives the allele for combinations from his mother always colorblind?
Since the mother would be considered a carrier, the gene will be produced in the offspring. the son will receive that gene and will be colorblind.
What must occur for a girl to be color blind?
The girl must have a copy of the gene on each X chromosome. This means that she must have a father who is colorblind and a mother who is either a carrier or is colorblind.
What is the genotype if a brown eyed persons mother was color blind and his father had blue eyes who's engaged to a person who's color blind whos father is normal vision?
The brown-eyed person likely has the genotype Bb for eye color, where B represents the brown allele and b represents the blue allele. Since the mother is colorblind (XbXb), she contributes an X chromosome with the colorblind allele. The father with blue eyes (bb) does not affect the X-linked colorblind trait. The engaged partner, being colorblind with a normal-vision father (XbY), would also have the genotype XbXb.
What is the chance that a daughter will be colorblind?
Color blindness is generally inherited in an X-linked recessive pattern. Since daughters have two X chromosomes, they need to inherit the color blindness gene on both X chromosomes to be colorblind. If the father is colorblind, he will pass on his X chromosome with the color blindness gene to his daughter, while the mother can pass on either a normal or affected X chromosome. Therefore, the chance of a daughter being colorblind depends on her mother's carrier status; if the mother is a carrier, there’s a 50% chance, but if she is unaffected, the chance is 0%.
Why is it not possible to get a colorblind female from a normal male and a heterozygous female?
Color blindness is typically inherited as an X-linked recessive trait. A colorblind female must have two copies of the colorblind allele (one from each parent), meaning she must inherit the allele from both her mother and father. In this scenario, the normal male (with a normal X chromosome) can only pass on a normal X chromosome to his daughters, while the heterozygous female has one normal X and one colorblind X, meaning she can pass on either allele. Therefore, the combination of a normal male and a heterozygous female cannot produce a colorblind daughter.
A woman with normal color bison has a colorblind daughter What genotype and phenotype of both parents?
The woman with normal color vision likely has the genotype XX, where X is the normal vision allele. The father, being colorblind, has the genotype X^cY, where X^c represents the colorblind allele. Their daughter, who is colorblind, must have inherited one X^c from her father and one X from her mother, resulting in the genotype X^cX. Hence, the woman's phenotype is normal color vision, while the father's phenotype is colorblind, and the daughter's phenotype is colorblind.
