Exam 46: Animal Reproduction

For your internship at the local zoo, you have been assigned to help with the new orangutan-breeding program. Little is known about orangutan reproductive hormones, but hormone feedback cycles are often the same in closely related animals. You have been asked to use your knowledge of the interactions of human reproductive hormones to recommend injections to promote ovulation in a female orangutan when a visiting male arrives for a brief breeding visit. -Which of the following hormones would you use if you want to induce ovulation in a few days?

Two contraceptive methods that are considered permanent and that block the gametes from moving to a site where fertilisation can occur are ________.

Menopause is characterised by ________.

Oestrogens found in the environment have raised concerns about effects on reproductive health of animals. Researchers studied the effects that oestrogens 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-oestradiol (5, 25, and 100 nanograms/litre) 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-oestradiol 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-oestradiol 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-oestradiol, 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-oestradiol 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-oestradiol would you suggest is safe to prevent feminisation of fish?

Animals that have external fertilisation are most likely to reproduce in which of the following areas?

Which statement about human reproduction is false?

In humans, the follicular cells that remain behind in the ovary following ovulation become ________.

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 neighbouring 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?

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 neighbouring pairs. Apparently, mating outside of monogamous pairings is widespread in species 2. -What would you expect to observe if you examined the reproductive tracts of the female birds in the species?

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

Environmental cues that influence the timing of reproduction generally do so by ________.

Which of the following structures in females is analogous in function to the vas deferens in males?

Labour contractions can be increased by the medical use of a synthetic drug that mimics the action of ________.

Among human males, both semen and urine normally travel along the ________.

________ is a medical procedure that prevents oocytes from reaching the uterus.

What makes sexually reproduced offspring genetically different from their parents?

Which of the following characterises parthenogenesis?

Which of the following organisms reproduces by fission?

At the time of fertilisation, the maturation of the human oogonium has resulted in ________.

Among mammals, the male and female genital structures that consist mostly of erectile tissue include the ________.