Hemophilia A is an X-linked recessive genetic condition. In humans it is due to a mutation in the F8 gene, which encodes a protein called coagulation factor VII. Coagulation factors are proteins important in blood clotting. Individuals with hemophilia, when injured, bleed longer than a normal, healthy individual; the inability to normally clot blood can be life threatening. Hemophilia is much more common in males than in females. Which of the following does NOT explain why this is so?

A. A female with one defective allele makes enough normal coagulation factor VII to clot blood and will not have hemophilia A
B. Males are hemizygous for the F8 gene, so they will have hemophilia A if they have one defective allele
C. Females have to receive a defective allele from both their mother and their father to get hemophilia A
D. Males have to receive a defective allele only from their father to get hemophilia A


D. Males have to receive a defective allele only from their father to get hemophilia A

Biology & Microbiology

You might also like to view...

Which type of plant hormone is structurally similar to adenine?

a. brassinosteroid b. abscisic acid c. ethylene d. cytokinin e. systemin

Biology & Microbiology

Consider an erythrocyte with an internal glucose concentration of 0.1 mM and an external glucose concentration of 5 mM. Each of the following is true about GLUT1 transport of glucose across the plasma membrane into the cell except

A) Keq is always equal to 1. B) ?G depends on the concentration gradient. C) inward movement is exergonic. D) ?G° is always equal to 0. E) the rate of GLUT1 transport is faster than that of simple diffusion.

Biology & Microbiology

Theoretically, based on the cohesion-tension mechanism, what should be the maximum height for the tallest trees?

a. about 3 m b. about 50 m c. about 75 m d. about 130 m

Biology & Microbiology

Seth purchased five pounds of live crayfish and realized that the outer shells were made of a tough carbohydrate similar to that used to make the carapace of a cockroach. What do you think the outer shells of the crawfish are made of?

A. glycogen B. fibrin C. chitin D. cellulose E. amylopectin

Biology & Microbiology