Exam 46: Animal Reproduction

A primary response by the Leydig cells in the testes to the presence of luteinizing hormone is an increase in the synthesis and secretion of ________.

Among nonmammalian vertebrates, the cloaca is an anatomical structure that functions as ________.

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?

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?

In male mammals, excretory and reproductive systems share

For which of the following is the number the same in spermatogenesis and oogenesis?

Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell process occurs to generate this type of offspring?

You decide to study two species of birds, both of which form monogamous pairs (one male and one female). In species 1, you find that the eggs in a pair's nest are in fact almost always the offspring of that pair. In species 2, you are surprised to find that many of the eggs in a nest were actually fathered by males of neighboring pairs. Apparently, mating outside of monogamous pairings is widespread in species 2. Given this information, what would be the logical prediction to make before comparing testes size of males of the two species?

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?

Refer to the following figure, which diagrams the reproductive anatomy of the human female, to answer the question. In the figure, which structure is the site of embryo implantation?

For which of the following is the number the same in human males and females?

Menopause is characterized by ________.

During human gestation, rudiments of all organs develop

Asexual reproduction results in greater reproductive success than does sexual reproduction when ________.

Which statement about human reproduction is false?

Mature human sperm and ova are similar in that they ________.

Which of the following is a true statement?

Which hormone is released from the Sertoli cells that inhibits the release of follicle stimulating hormone?

For water fleas of the genus Daphnia, switching from a pattern of asexual reproduction to sexual reproduction coincides with ________.

Refer to the following figure, which diagrams the reproductive anatomy of the human male, to answer the question. In the figure, which letter points to the prostate gland?