Consider this human pedigree for a vision defect.

Question

Consider this human pedigree for a vision defect.

What is the most probable mode of inheritance of the disease? Identify any discrepancies between the pedigree and your proposed mode of transmission, and provide possible explanations for these exceptions.

Accepted Answer

Hey, everyone. Let's take a look at this question together. A female with normal vision has a color blind son who also has hemophilia. The father of the female did not have hemophilia or color blindness. The recessive alleles that cause color blindness and hemophilia are designated by X little B and X little H respectively. While the normal dominant alleles or the same are designated by X big B and X big H respectively. Based on this information, determine the genotype of the female. So the information provided in the question tells us that we have a father of the female, we have the female and we have the sun of the female and we know that the father does not have hemophilia or color blindness. And so he has that X N Y chromosome where his X chromosome has the dominant alleles because those are the normal alleles for hemophilia and color blindness. And so his X chromosome is designated by having both the big B and big H khalil. And of course, there are no rules attached to his why. And so because he is the father of the female, we know that the female inherits that X with the normal dominant khalil from the father. And we know that because the son of the female has hemophilia and color blindness. His X chromosome must have the recessive alleles for both hemophilia and color blindness. Which means that the other chromosome that the female who is the mother of the son has both recessive alleles. And so that means that answer choice B is the correct answer because we know that the father of the female does not have hemophilia or color blindness. And so his ex N Y chromosome has the X with both dominant alleles, since those are the normal alleles, and we know that the son of the female has both color blindness and hemophilia. So therefore, his X chromosome has those recessive alleles which cause color blindness and hemophilia. Therefore, the chromosomes found within the female must represent that X that we see in the father as well as the X that we see in the sun since she does not have hemophilia or color blindness and neither does the father. However, her son does have hemophilia and color blindness. So that means that the other X chromosome from the mother is represented by those recessive alleles. Making answer choice B, the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

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Consider this human pedigree for a vision defect.

What is the most probable mode of inheritance of the disease? Identify any discrepancies between the pedigree and your proposed mode of transmission, and provide possible explanations for these exceptions.

My Courses

Chemistry

Biology

Math

Physics

Business

Social Sciences

Programming

Product & Marketing

Consider this human pedigree for a vision defect.What is the most probable mode of inheritance of the disease? Identify any discrepancies between the pedigree and your proposed mode of transmission, and provide possible explanations for these exceptions.

Consider this human pedigree for a vision defect.

What is the most probable mode of inheritance of the disease? Identify any discrepancies between the pedigree and your proposed mode of transmission, and provide possible explanations for these exceptions.