Assignment - 15. Factors Studied

night blindness rolling eyeballs nonfunctional sweat glands white forelock muscular dystrophy certain deafness color blindness diabetes

(Select all that apply.) Choose from the following list of diseases those that are sex-linked.

X bX b X bY X BX b

Choose from the following list the three genotypes the parents must have in order for a daughter to have XbXb ?

female w/ trait - male w/ trait

Click an item in the list or group of pictures at the bottom of the problem and, holding the button down, drag it into the correct position in the answer box. Release your mouse button when the item is place. If you change your mind, drag the item to the trashcan. Click the trashcan to clear all your answers. Complete the following diagram by placing the graphics on their appropriate spots.

True

A female can be susceptible to expressing hemophilia.

False

Hemophilia is a condition where the blood clotting action is dangerously high.

False

In considering sex-linked inheritance, both sexes are equally susceptible to the manifestation of the trait.

False

In sex-linked inheritance, females are most susceptible because they have only one X chromosome. Therefore, whichever gene is present, be it dominant or recessive, it is expressed. The male has two X chromosomes, and in order to be expressed, both genes must be recessive.

X bY X bX b

Mark the genotypes which express hemophilia.

yes-if the mother is not a possible carrier

The Talmud permitted a father with hemophilia to have his son circumcised. Would this preclude all possible problems?

True

The blood type trait is controlled by more than two alleles for a given gene and therefore is called multiple alleles.

X bX b

What would be a female bleeder's genotype? (Let XB stand for the normal condition for clotting and Xb stand for the recessive hemophilia allele.)

because the disease is not on the "Y" chromosome and Helena does not have the trait

Why didn't Charles and Alexander, the grandsons of Queen Victoria, inherit hemophilia?

because they did not receive the recessive gene (X b) from their mother.

Why didn't the two sons of Queen Victoria (Alfred and Arthur) display hemophilia? (refer to pedigree chart)

because the probability of hemophilia would be 50%

Why would it be wise for a woman carrying the hemophilia gene to keep her son from being circumcised?