What would you expect for an individual with the genotype XXY? The individual would develop as a male. Hemophilia is a sex-linked disorder that is caused by a recessive allele. If the mom is a carrier of hemophilia and the dad doesn't have hemophilia, what is the chance that they will have a child with hemophilia?
But under the right circumstances, females can also inherit the disease phenotype. Sort the following descriptions of autosomal and sex chromosome inheritance by dragging them into the "Autosomal" box or into the "Sex-linked" box. Some descriptions may apply to both types of inheritance and should be dragged into the "Both" box.
It is difficult to study the inheritance of genetic disorders in humans because it is not ethical to set up controlled matings between humans. And humans produce very few offspring in their lifetime compared to other species.
And humans produce very few offspring in their lifetime compared to other species. As a result, genetics are frequently studied in model organisms like fruit flies or pea plants. The fact that humans pick their own mates would make it hard for researchers to control how genes were passed from parent to offspring.
XAXa × XaY. You chose the only pair of parents, XAXa × XaY , that could have a daughter with the disease phenotype. If a girl inherits the recessive allele on the X chromosome from her mother and on the X chromosome from her father, then she will exhibit the recessive phenotype of an X-linked disorder.
Remember that a males inherit one X chromosome from the mother and a Y chromosome from the father. Because they only have one copy of the X chromosome, inheritance of the one recessive X-linked allele will result in the recessive phenotype.
Males suffer from the disorder, which affects the formation of blood cells and the immune system, more than females because females can inherit a healthy dominant allele on their second X chromosome which will save them from the disorder. Consider an X-linked recessive disorder as described in the video.
Because the pedigree indicates that a female introduced the mutation into the family and only males were affected, the gene must be on the X chromosome. Below are pictures of four different types of abnormalities in chromosome structure. Match each picture with the correct name of the chromosome structure problem.
X-linked disorders like hemophilia and color blindness are more common in males, whereas autosomal disorders like cystic fibrosis exhibit the same inheritance pattern in males and females.
X-linked disorders. Duchenne muscular dystrophy, hemophilia, and fragile X syndrome are all X-linked disorders whose genes are found on the X chromosome. Because males only have one X chromosome, they exhibit the disease significantly more frequently than females.
There is a misconception that girls cannot inherit recessive X-linked disorders. Girls can in fact inherit these disorders, but at a lower rate than boys. The following choices give the genotypes for pairs of mothers and fathers. Which pair of parents could have a daughter with the recessive disorder a?