James is a 42-year-old man with hemophilia, a sex-linked recessive condition. His daughter, Susan, who has normal blood clotting, is married to Fred who also has hemophilia. Susan and Fred are expecting their first child and an ultrasound shows that the fetus is male. What is the approximate probability that their new son will have hemophilia?
A. 1/4
B. 1/2
C. 1 (100%)
D. 3/4
E. 2/3
Ans: B. 1/2
You might also like to view...
This defect means that there is a problem at the level of __________
a. nucleotides b. amino acids c. triglycerides d. glucose molecules
Post-translational modifications are responsible for
a. activation, inhibition, and stabilization of enzymes. b. inhibition of enzymes only. c. activation, inhibition, and synthesis of enzymes. d. synthesis of enzymes and allosteric enzyme control. e. synthesis of enzymes only.
Which of the following statements about breast cancer is false?
a. Cigarette smoking, obesity, and alcohol use have all been linked to a higher risk of breast cancer. b. With early diagnosis and treatment, almost 90% of breast cancer patients survive for five years. c. Breast cancer is the leading cause of cancer deaths in women. d. Growth of about two-thirds of breast cancers is enhanced by circulating estrogens and progesterone. e. 10% of breast cancers are familial.
Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! You realize that this cell is
A) undergoing cytokinesis. B) in the S phase of interphase. C) in the G1 phase of interphase. D) about to undergo mitosis.