Which of the following is true if a colorblind woman and a man with normal vision have children?

Red-green color blindness is a sex-linked recessive trait in humans.





a. None of their children will be colorblind


b. Half of their male children will be colorblind


c. Half of their female children will be colorblind


d. All of their female children will be colorblind


e. All of their male children will be colorblind








I ran out of questions so I'm going to ask another here.





Multiple crosses involving genes known to occur on the same chromosomes produce frequencies of phenotypes that suggest that there is a high rate of crossover between these two genes. Which of the following is the most likely explanation for the phenotypic frequencies observed due to crossing over??





a. The two genes are far apart from one another


b. The two genes are both recessive


c. The two genes have incomplete dominance


d. The two genes are both located far from the centromere


e. The two genes are on the same chromatid.





If possible, please tell me the logic behind your answers. Thanks!Which of the following is true if a colorblind woman and a man with normal vision have children?
First question: E


explanation:





...................Xc.............Xc..


XC...........XCXc.........XCXc..


Y...............XcY...........XcY..





(I apologize if the table is messed up, but it shouldn't be. Ignore the periods.)


Because the only way a woman can be colorblind is 2 recessive, and male only has one, and since he's not colorblind, it's dominate.





Second question: E


Because they are on the same chromatid, if they get that chromatid from one parent, they will get it on the same chromosome from the same parent.Which of the following is true if a colorblind woman and a man with normal vision have children?
The answer to your first question is ';E. All of their male children will be colorblind.';





The explaination is rather simple. The gene for colorblindness is on the X chromosome. For a woman to be colorblind, she has to have two colorblind X chromosomes. If she has only one affected X chromosome and one normal, she is then known as a carrier, meaning she can pass it on to her offspring. A colorblind woman can only pass on a color blind X chromosome. Because the father has normal vision, the colorblind gene is not part of his X chromosome, so their daughters will be carriers, but not exhibit colorblindness symptoms themselves. Their sons, however, will have no protection against colorblindness from the Y chromosome so the gene will be expressed as red-green colorblindness.





I believe the answer to your second one is that the genes are on the same chromatid, placing them in close proximity making crossover more possible. I can't say if for sure, though. I'll try and find out for you, though.
Idk! that is totally hard!!
For the first question the answer is E. This is because the gene for colourblindness is located in the X chromosome, the gene for colourblindness is recessive so both of the mother's X chromosomes have the colour blindness gene. The father have normal gene on his X chromosome, there are no corresponding gene on his Y chromosome. All male children will receive the colourblind gene from the X chromosome of their mother, because the Y chromosome they receive from their father do not have the gene to mask it then they all will be colourblind. All of their female children will be carrier because the normal gene they receive from their father's X chromosome will mask the colourblindness gene on the X chromosome they receives from their mother.





For the second question the answer is A, when two genes are far apart there is a greater probability that they will be switched during crossing over.
1=a if colorblindness is a recessive trait then it wont show up without 2 carriers. and im sorry but i dont know what 2 is
woman arent colorblind.......they just have the gene but they pass it on to their sons......women cant be colorblind. you should've learned that in science when you were somewhat young.
none of the children will be color blind, this kinda stuff comes i think everyother generation
Its not a proportionality %26amp; i think only guys can be colorblind. According to researches only 7.XX% of guys are colorblind. so... yeah








and #2 ionno im only 13 :o
1) all males will be color blind - do a simple punnet square crossing xy and xx. color blindness is recessive, so the mother must be homozygous for the trait. otherwise she wouldn't be color blind. so, the sons can only get an x from the mother. her x's all have the trait and the father will donate a y to the boys.





2) the two genes are far from the centromere - just a guess based on what i know about crossovers.





problem number one is very simple. if you can't figure that out, you better brush up on sex-linked and x-linked traits and punnet squares before the test. there will definitely be these kinds of questions on there.