And so this is a situation where you have a daughter, daughter with hemophilia, hemophilia, right over here. Well, it's X-linked, and the father only has one X chromosome. Females, however, can be genotypically normal, a carrier who is phenotypically normal, or affected with the disease.
As a result, they are blood type AB.
If each plant has the genotype RrAaand since the alleles for shape and color genes are independent, then they can produce four types of gametes with all possible combinations: RARarAand ra. So let's draw-- call this maybe a super Punnett square, because we're now dealing with, instead of four combinations, we have 16 combinations.
Mendelism 2nd ed. And they say it's a hemophiliac man. Views Read Edit View history. Subscribe to our YouTube Channel:. For a genotype such as Bb the alleles are different from one another. And let's say the other plant is also a red and white.
For many genetic diseases, a DNA test can determine whether a person is a carrier. An example of this is Tay—Sachs, a fatal disorder of the nervous system. In both cases, the person is blood type A. Our contemporary understanding of genetics rests on the work of a nineteenth-century monk.
And since it is an X-linked recessive trait, we're going to be dealing with the sex chromosomes. He articulated the principles of random segregation and independent assortment to account for the inheritance patterns he observed. And so that one X chromosome is going to have the hemophilia allele.
Consider a couple in which one parent is heterozygous for this disorder and who therefore has neurofibromatosis , Nn , and one parent is homozygous for the normal gene, nn.