53) is a medical procedure that prevents oocytes from reaching the uterus.
A) Vasectomy
B) Endometriosis
C) Tubal ligation
D) Coitus interruptus
... [Show More] Answer: C
Bloom's Taxonomy: Knowledge/Comprehension Section: 46.5
54) A vasectomy .
A) eliminates spermatogenesis
B) eliminates testosterone synthesis
C) prevents implantation of an embryo
D) prevents sperm from entering the male urethra Answer: D
Bloom's Taxonomy: Knowledge/Comprehension Section: 46.5
55) Once uterine contractions have begun, the female body releases several hormones that act in a positive feedback loop. The purpose of this feedback loop is .
A) to promote the development of a new follicle
B) to ensure continued contractions until labor is complete
C) inhibit the release of prostaglandins
D) decrease the number of oxytocin receptors in the uterus Answer: B
Bloom's Taxonomy: Application/Analysis Section: 46.5
56) A pregnant woman comes into the hospital past her due date. The doctor decides it is time for the baby to be delivered. Before performing a cesarean section, the doctor wants to try to induce labor. Which of the following would she most likely inject?
A) progesterone
B) luteinizing hormone (LH)
C) follicle-stimulating hormone (FSH)
D) oxytocin Answer: D
Bloom's Taxonomy: Application/Analysis Section: 46.5
57) An ectopic pregnancy occurs when a fertilized egg implants somewhere other than in the lining of the uterus. Usually it implants in the oviduct. Which of the following would be the most likely explanation for such a pregnancy being unsuccessful?
A) The orientation of the baby would be sideways.
B) Human chorionic gonadotropin (hCG) cannot be produced in the oviduct.
C) The lining of the oviduct is unable to support the developing fetus.
D) The necessary hormones cannot reach the developing fetus in the oviduct. Answer: C
Bloom's Taxonomy: Application/Analysis Section: 46.5
58) Use the following information to answer the question.
Estrogens found in the environment have raised concerns about effects on reproductive health of animals. Researchers studied the effects that estrogens in the water have on sexual differentiation in zebrafish. They exposed embryo-larval (0-21 days post-hatching), juvenile (21-42 days post- hatching), and adult (over 200 days post-hatching) fish to three concentrations of 17β-estradiol (5, 25, and 100 nanograms/liter) that are within the range of concentrations found in water leaving sewage treatment plants in different countries. They then examined the proportion of males and females when the fish exposed at embryo-larval and juvenile stages reached adulthood. Embryo-larval stage fish that had been exposed to 100 ng/l 17β-estradiol resulted in adult populations that had substantially more females than males compared to control groups.
Embryo-larval fish that had been exposed to 5 and 25 ng/l of 17β-estradiol did not show a statistically significant shift in the proportion of females. (Brion, F., C. R. Tyler, X. Palazzi, B. Laillet, J. M. Porcher, J. Garric, and P. Flammarion. 2004. Impacts of 17β-estradiol, including environmentally relevant concentrations, on reproduction after exposure during embryo-larval-, juvenile-, and adult-life stages in zebrafish (Danio rerio). Aquatic Toxicology 68:193-217.)
What is the significance of using the concentrations of 5, 25, and 100 ng/l of 17β-estradiol in this experiment?
A) These concentrations are similar to those found in many animals.
B) These concentrations are found in the environment.
C) These concentrations are effective, yet not lethal to the fish.
D) These concentrations are standard in toxicology assays. Answer: B
Bloom's Taxonomy: Application/Analysis Section: 46.5
59) Use the following information to answer the question.
Estrogens found in the environment have raised concerns about effects on reproductive health of animals. Researchers studied the effects that estrogens in the water have on sexual differentiation in zebrafish. They exposed embryo-larval (0-21 days post-hatching), juvenile (21-42 days post- hatching), and adult (over 200 days post-hatching) fish to three concentrations of 17β-estradiol (5, 25, and 100 nanograms/liter) that are within the range of concentrations found in water leaving sewage treatment plants in different countries. They then examined the proportion of males and females when the fish exposed at embryo-larval and juvenile stages reached adulthood. Embryo-larval stage fish that had been exposed to 100 ng/l 17β-estradiol resulted in adult populations that had substantially more females than males compared to control groups.
Embryo-larval fish that had been exposed to 5 and 25 ng/l of 17β-estradiol did not show a statistically significant shift in the proportion of females. (Brion, F., C. R. Tyler, X. Palazzi, B. Laillet, J. M. Porcher, J. Garric, and P. Flammarion. 2004. Impacts of 17β-estradiol, including environmentally relevant concentrations, on reproduction after exposure during embryo-larval-, juvenile-, and adult-life stages in zebrafish (Danio rerio). Aquatic Toxicology 68:193-217.)
You are assigned to write the report to the Environmental Protection Agency that needs to decide what level of 17β-estradiol to permit in sewage output. You do not want to make the level any lower than necessary, because it requires substantial additional money for the extra treatment of sewage. Given the data presented, what concentration of 17β-estradiol would you suggest is safe to prevent feminization of fish?
A) 2.5 ng/l
B) 12.5 ng/l
C) 25 ng/l
D) 100 ng/l Answer: C
Bloom's Taxonomy: Synthesis/Evaluation Section: 46.5
60) Which of the following is the most likely explanation for the absence of a protective filter blocking the passage of alcohol between the maternal and fetal circulations in humans?
A) There has not been enough time to evolve such a barrier.
B) Such a barrier would probably also block important molecules that need to be passed to the fetus.
C) The maternal and fetal blood mix directly together in an area with many villi, so a barrier is impossible.
D) Alcohol has some positive effects on the fetus, so evolution has resulted in an intermediate level of filtering that blocks all but the worst abuses of alcohol.
Answer: B
Bloom's Taxonomy: Synthesis/Evaluation Section: 46.5
46.2 Student Edition End-of-Chapter Questions
1) Which of the following characterizes parthenogenesis?
A) An individual may change its sex during its lifetime.
B) Specialized groups of cells grow into new individuals.
C) An organism is first a male and then a female.
D) An egg develops without being fertilized. Answer: D
Bloom's Taxonomy: Knowledge/Comprehension
2) In male mammals, excretory and reproductive systems share
A) the vas deferens.
B) the urethra.
C) the seminal vesicle. [Show Less]