IB 140 Midterm #1 PRACTICE EXAM (lecture topics 1-5)

IB 140 Midterm #1 PRACTICE EXAM (lecture topics 1-5) For all the questions on this exam, the correct answer is the single best answer that is available in the answer key. 1) Which of the following is NOT true about steroid hormones? A. derived from cholesterol B. receptor is on the cell membrane C. When a steroid hormone binds to its receptor the steroid/receptor complex undergoes a conformational change that exposes DNA-binding domain D. Steroid hormones may be bound by globulins (carrier proteins) in blood E. 97-98% of estradiol is bound by globulins 2) Which of the following statements is NOT true about melatonin? A. secreted by the pineal gland B. high doses stimulate reproductive gonadal systems C. dark exposure increases melatonin secretion D. can cause mild sedative effect E. Involved in circadian rhythms 3) Which is the following is true about neurosecretory neurons? A. cell bodies lie in pitutitary B. speed of nerve impulses are faster than regular neurons C. release neurohormones e.g., oxytocin D. these neurons extend through the anterior pituitary gland (adenohypophysis) E. neurosecretory neurons are more common than regular neurons 4) Which of the following is true about prolactin? A. stimulates contractile cells of mammary glands B. support mammary glands in females to produce milk C. prolactin releasing hormone is produced in pituitary D. prolactin release inhibiting hormone is produced by pineal gland E. prolactin stimulates uterine smooth muscle contractions 5) What is an effect of high levels of estrogen? A. negative feedback on GnRH B. increases FSH more than LH C. increases sensitivity of pituitary to GnRH D. inhibits GnRH surge center E. reduces libido 1

6) Which of the following statements is true? A. follistatin binds to inhibin and blocks its action B. activin inhibits release of FSH C. activin opposes the action of follistatin D. inhibin suppresses secretion of FSH E. inhibin acts directly on hypothalamus 7) Which of the following is NOT an example of a female primary sexual characteristic? A. characteristic distribution of fat in torso B. labia minora C. ovaries D. vagina E. oviducts 8) Which of the following is true about follicles? A. zona pellucida is a transparent membrane on the outside of the follicular wall. B. within the follicle, the theca cells are the layer of cells immediately around and next to the oocyte. C. follicles are located in medulla of ovary. D. during days 7-10 in a 28 day cycle, follicular cells have more LH receptors than FSH receptors. E. newborn infants on average possess 1-2 million follicles. 9) Steroid hormone secretions in the gonads are under the DIRECT control of which hormone(s)? A. GnRH alone B. FSH alone C. LH alone D. FSH & LH E. FSH, LH, and GnRH 10) Which of the following is true about FSH? A. follistatin can indirectly inhibit FSH B. FSH is produced in hypothalamus C. activin inhibits release of FSH D. highest FSH level is in the mid-follicular phase E. primary outcome of FSH is progesterone production 11) Which of the following is true about LH? A. stimulate mitosis in granulosa cells B. controls conversion of androstenedione to estrogen C. primary outcome of LH is estrogen production D. shortly before ovulation, LH receptors appear on granulosa cells E. LH is inhibited by inhibin 2

12) Which of the following cell types is/are present in some stage of follicle development? A. granulosa cells B. theca cells C. luteal cells D. granulosa & theca cells E. granulosa, theca, & luteal cells 13) Which type of follicle contains a fluid filled antral cavity? A. primordial B. primary C. secondary D. tertiary E. quaternary 14) On average, how many oocytes are present in females at puberty? A. 7 million B. 1.5 million C. 600,000 D. 200,000 E. 100,000 15) Which is the most important hormone product of the!5 pathway? A. progesterone B. DHEA (dehydroepiandrosterone) C. androstenedione D. testosterone E. estradiol 16) What event most DIRECTLY triggers the completion of the 1 st meiotic division in the oocyte? A. estrogen surge in follicular cycle B. development of antral fluid in tertiary follicles C. LH surge D. FSH surge E. progesterone surge 17) When a single primary oocyte goes through both 1st and 2nd of meiotic divisions, how many ootids (mature haploid oocytes) are generated? A. 1 B. 2 C. 3 D. 4 E. 8 3

18) Which of the following is NOT true about lesser vestibular glands (Skene s glands)? A. secretes fluids B. positioned below & to either side of urethral orifice C. homologous to seminal vesicle glands in males D. adjacent to labia minora 19) What is the succession of structures from where human milk is synthesized to its release from the nipple? A. secondary mammary tubule, mammary lobule, ampulla, mammary duct, lactiferous duct, nipple B. mammary lobule, secondary mammary tubule, ampulla, mammary duct, lactiferous duct, nipple C. secondary mammary tubule, mammary lobule, mammary duct, ampulla, lactiferous duct, nipple D. mammary lobule, mammary duct, secondary mammary tubule, lactiferous duct, ampulla, nipple E. mammary lobule, secondary mammary tubule, mammary duct, ampulla, lactiferous duct, nipple 20) Which of the following is NOT true about mammary gland control? A. the mammary gland tissue is relatively inactive in prepubital females B. during luteal phase of menstrual cycle rising estrogen and progesterone causes breast glandular tissue to enlarge C. during pregnancy, rising estrogen and progesterone in the blood, causes glandular tissue to enlarge and ducts to branch D. prolactin causes ejection of milk from the nipple through contraction of myoepithelial cells that surround each alveolus E. Nursing stimulates oxytocin release 21) Which of the following statements is true about female menstrual cycle? A. College women who have coitus frequently have menstrual cycles that are more variable in length than in women who abstain from sex B. Younger women tend to have shorter cycles than older women C. Majority of women have exactly 29.5 day cycles D. Human females are spontaneous ovulators, which means ovulation occurs periodically (monthly) whether or not coitus occurs 22) Why does FSH level drop during the middle part of the follicular phase? A. negative feedback from estrogen B. negative feedback from progesterone C. lack of negative feedback from estrogen D. lack of negative feedback from progesterone E. positive feedback from estrogen 4

23) Which of the following is NOT true on day 3 of the menstrual cycle? A. FSH is gradually rising B. LH is gradually rising C. Estrogen is rising D. Progesterone is rising E. Some tertiary follicles are 10 mm 24) The!5 pathway pathway is most active during which of these stages of the menstrual cycle? A. menses B. early-follicular phase C. mid & late follicular phase D. at ovulation E. luteal phase 25) As a result of positive feedback from very high estrogen levels, there is a large LH surge with a smaller rise in FSH. Why does FSH not rise like LH? A. negative feedback from estrogen B. inhibition of FSH from inhibin C. negative feedback from progesterone D. inhibition of FSH by activin E. negative feedback from testosterone 26) Which of the following occurs just before ovulation? A. Graffian follicle shifts from the!4 pathway to the!5 pathway B. Peak of LH surge C. Twenty Graffian follicles in each ovary reach maturity D. Progesterone levels drop E. 2 nd stage of meiosis is completed in the oocyte 27) Which of the following is NOT an indicator of the presence of the luteal phase? A. Endometrial lining thick & spongy B. high levels of progesterone C. pregnanediol in urine D. breast enlargement E. presence of a Graffian follicle 28) Which of the following is true about the luteal phase? A. high progesterone levels result in positive feedback B. around day 24 in a 28 cycle, the corpus luteum starts to disintegrate C. luteal phase last 21 days D. high FSH levels E. high testosterone levels 5

29) If a woman consistently has a 32 day menstrual cycle, how long would her luteal phase be? A. 18 days B. 16 days C. 14 days D. 12 days E. 10 days 30) In most women, body fat needs to be " what % for menstrual cycles to occur? A. 8% B. 12% C. 22% D. 32% E. 38% 31) Which of the following is NOT a male secondary sexual characterstic? A. facial hair B. higher average height than women C. larger muscles D. lower voice E. prostate gland 32) Which of the following describes the process by which haploid spermatids are transformed into haploid spermatozoa (sperm cells)? A. spermiation B. spermatogenesis C. spermiogenesis D. mitotsis E. meiosis 33) Each spermatic cord contains all the following except? A. epididymus B. one artery C. testicular nerve D. two veins E. vas deferens 34) Which of the following is the process by which a diploid spernatogonium transforms into four haploid spermatids? A. spermiation B. spermatogenesis C. spermiogenesis D. mitotsis E. seminiferous transformation 6

35) Transport of sperm from its site of production to its delivery to the ejaculatory ducts? A. tubulus rectus, seminiferous tubule, rete testes, vasa efferentia, epididymus, vas dererens, ejaculatory duct B. seminiferous tubule, rete testes, tubulus rectus, vasa efferentia, epididymus, vas dererens, ejaculatory duct C. seminiferous tubule, tubulus rectus, rete testes, vasa efferentia, epididymus, vas dererens, ejaculatory duct D. seminiferous tubule, tubulus rectus, vasa efferentia, rete testes, epididymus, vas dererens, ejaculatory duct E. seminiferous tubule, vasa efferentia, tubulus rectus, rete testes, vas dererens, epididymus, ejaculatory duct 36) What is the product of the 2 nd meiotic division in sperm? A. spermatogonium B. primary spermatocyte C. secondary spermatocyte D. spermatids E. spermatozoa 37) Human males produce sperm at a rate of how many per minute? A. 6,000,000 sperm per minute B. 1,000,000 sperm per minute C. 60,000 sperm per minute D. 600 sperm per minute E. 1 sperm per minute 38) Which of the following is true about Leydig cells? A. secrete inhibin B. secrete Mullerian-inhibiting substance C. secrete testosterone D. are phagocytic E. form tight junctions to provide blood-testis border 39) Testosterone is converted to estrogen in men in which cell type? A. sertoli cells B. leydig cells C. germ cells D. myoid cells E. spermatids 7

40) Where is androstenedione converted to estrone in females? A. liver cells B. fat cells C. protein cells D. hair follicles on scalp E. hair follicles in pubic and axillary areas 41) Where is testosterone NOT converted to DHT (dihydroxytestosterone)? A. facial hair follicles B. prostate C. penis D. scrotum E. epididymus 42) Which of the following is not a male accessory duct? A. seminal vesicles B. rete testes C. vas efferentia D. vas deferens E. urethra 43) What is the layer of smooth muscle under the skin that contracts or relaxes in response to temperature so as to maintain scrotal testis temperature 3.1ºC below core body temperature? A. cremaster B. tunica dartos C. tunica albuginea D. tunica vaginalis E. tubulus rectus 44) The gonadal indifferent stage lasts until the end of which week of development? A. 5 th week B. 6 th week C. 7 th week D. 8 th week E. 9 th week 45) Which of the following stimulates production of testes-determining factor (TDF)? A. SOX-9 B. SRY (sex-determining region of the Y) C. MIS (mullerian-inhibiting substance) D. DAX1 E. Dihydroxytestosterone 8

46) Which of the following does NOT develop from mullerian ducts? A. oviducts B. ovaries C. uterus D. cervix E. upper 1/3 rd of vagina 47) Male orchidectimized male rat embryo receives testosterone but no MIS. How will the development of the wolffian and mullerian systems be affected? A. only mullerian duct system develops B. only wolffian duct system develops C. both mullerian and wolffian duct systems develop D. neither wolffian or mullerian systems develop 48) Which of the following is an example of homologous structures? A. Genital tubercle differentiates into the female clitoris and the male ventral aspect of the penis B. Urogenital folds forms the female labia majora and the male dorsal aspect of the penis shaft C. Labioscrotal swelling forms female labia minora and male scrotum D. Urethral tissue forms female greater and lesser vestibular glands and male prostate & bulbourethral glands E. Mullerian ducts form female oviducts and male vas deferens 49) Which of the following is NOT true about intersex humans? A. gonadal systems with both ovarian and testes tissue present B. 46:XX: aberrant recombinations result in X chromosomes carrying SRY, resulting in XX males C. 46:XY: aberrant recombinations result in Y chromosomes that have lost SRY, resulting in XY females D. 46:XY karyotype in 70% E. No documented cases of self-fertilization, as both viable eggs and sperm are not typically present in intersex individuals 50) What hormone production deficiency causes infant XY Guevedoces individuals to have external genitalia that look female? A. testosterone B. dihydroxytestosterone C. androstenedione D. estrogen E. progesterone 9

KEY: 1. B 2. B 3. C 4. B 5. C 6. D 7. A 8. E 9. D 10. A 11. D 12. E 13. D 14. D 15. E 16. C 17. A 18. C 19. E 20. D 21. D 22. A 23. D 24. C 25. B 26. B 27. E 28. B 29. C 30. C 31. E 32. C 33. A 34. B 35. C 36. D 37. C 38. C 39. A 40. B 41. E 42. A 43. B 44. C 45. B 46. B 47. C 48. D 49. D 50. B 10