highly talented 22-year-old female college athlete has just qualified to compete in the Summer Olympics. However, when she is required to undergo laboratory testing to measure testosterone levels, she is informed that she will not be permitted to compete because her testosterone levels are “too high for a female athlete”. Further medical and genetic testing reveal that she has a condition known as Complete Androgen Insensitivity Syndrome. She promptly hires an attorney to appeal the decision.   The Olympic Committee maintains that her elevated testosterone levels will give her an unfair advantage over her fellow female athletes. Is this accurate? Please provide scientific support for your answer.

Fetus A and Fetus B are developing within their own biological mothers who are unrelated.  Fetus A and Fetus B both experience 3 weeks of very high blood lead levels: a known teratogen.  After birth, Baby A is relatively healthy and appears to be unaffected by the high fetal BALs it experienced.  However, Baby B is exhibiting clear signs of birth defects and developmental delays.  Name two reasons why Baby A and Baby B may have been differentially impacted by this teratogen.

With reference to sex determination in humans, discuss: i) X chromosome inactivation; and ii) Testicular feminization

Define the term thecodont.

Colorblindness is an X-linked trait found in humans. What are the chances that a colorblind man will pass it on to his son? Please explain.

One of the first drugs used for targeted cancer therapy is tamoxifen, used to treat estrogen-receptor breast cancer. What general conclusions can you draw about the targeted drug therapy and genotype?

Neural Tube Defects (NTDs) are one of the most severe congenital malformations. A study was conducted to determine whether supplementation with folic acid or a mixture of seven other vitamins (A, D, B1, B2, B6, C, and nicotinamide) around the time of conception could prevent neural tube defects. A total of 1817 women at high risk of having a pregnancy with a neural tube defect (because of a previous affected pregnancy) were allocated at random to one of four groups: 1) folic acid; 2) other vitamins; 3) both; 4) neither. 1195 had a completed pregnancy; 27 of these had a known neural tube defect, 6 in the folic acid groups and 21 in the two other groups.  This resulted in a risk ratio= 0.28. Based on the results of the study, which of the following is an appropriate conclusion? a)There is no difference in the effect of folic acid on NTDs b) None of these c) Folic acid increases risk of NTDs d) Folic acid is protective against NTDs

Jonah and Jana are siblings. Jonah has the genetic disorder cystic fibrosis, caused by inheriting one copy from each parent of a mutation in the CF gene. Jana does not have cystic fibrosis. Which of the following statements is/are true? (Select all that are true)   a)Jana does not have the gene that when mutant causes cystic fibrosis. b)Jana has the gene that when mutant causes cystic fibrosis. c)Jana has two copies of the allele that causes cystic fibrosis. d)Jana does not have two copies of the allele that causes cystic fibrosis.

Please answer this question.

Your cousin just had twins. She tells you that twinning occurs when two sperm fertilize the same egg. You reply when two sperm fertilize the same egg. What will be your reply?    a) yes, she is right, that is the most common source of twinning   b) no, only one sperm survives passage through the uterine cervix, so two sperm are never present at fertilization   c) no, cortical granules are used to prevent additional sperm penetration   d) no, twinning occurs when unfertilized eggs divide spontaneously and thus is parthenogenic in nature