The average sperm count in males is now lower than it was several decades ago. The reasons for the lower sperm count usually seen today are not known. What data might be helpful in order to formulate a testable hypothesis?

The average sperm count in males is now lower than it was several decades ago. The reasons for the lower sperm count usually seen today are not known. What data might be helpful in order to formulate a testable hypothesis?

Body Structures & Functions Updated

13th Edition

ISBN:9780357191606

Author:Scott

Publisher:Scott

Chapter21: Reproductive System

Section: Chapter Questions

Problem 2ATC

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Which of the following statements does NOT correctly describe a difference between the male and female reproductive systems? Select one: a. Testosterone has a major role in the development of secondary sexual characteristics in male reproductive systems, whereas LH promotes the development of secondary sexual characteristics in females. b. The male reproductive system mass produces large quantities of gametes each day, whereas the female reproductive system produces an average of a single gamete each month. c. The excretory and reproductive systems both use the urethra in males, whereas in females, there are separate tubes for the excretory and reproductive systems. d. The structures that produce gametes are exterior to the body in the male reproductive system, whereas the gametes are produced inside the body for females.
Although the most effective forms of oral contraceptive for women contain estrogen and progestin, some birth control pills contain a small dose of progestin only. This is because there are many risks and side effects associated with estrogen.Which of the following statements is NOT a reason for using a progestin-only oral contraceptive? Select one: a. Progesterone suppresses the maturation of follicles, thereby preventing ovulation of a mature ovum. b. Progesterone maintains the corpus luteum as corpus luteum releases a large amount of progesterone and some estrogen. c. Progestin-only oral contraceptives prevent the production of FSH and LH in the anterior pituitary. d. Progesterone suppresses the production of GnRH in the hypothalamus.
The chance of successful fertilization is approximately 18% in every cycle. Why does this statistic seem so low? All of the following statements provide a reason as to why the chance of fertilization is only 18% for every ovarian cycle EXCEPT Select one: a. Some sperm cells are not very motile, while others are formed without a tail. b. There are two Fallopian tubes and two ovaries, but only one of them releases an ovum every cycle. c. If more than one sperm fertilize an egg, multiple embryos can result. d. The vagina is very acidic, killing many sperm cells.
Which of the following statements correctly describes the development of the endometrium during the menstrual cycle? Select one: A. Estrogen causes accelerated development of the endometrium during the follicle stage and then maintains the thickness of the endometrium during the luteal stage. B. Progesterone causes the relatively slow development of the endometrium during the follicle stage and accelerates the thickening of the endometrium during the luteal stage. C. Estrogen causes the relatively fast thickening of the endometrium during the follicular stage. Progesterone maintains the thickness of the endometrium during the luteal phase. D. Estrogen causes the relatively slow development of the endometrium during the follicular stage. Progesterone causes accelerated thickening of the endometrium during the luteal phase.
Figure 18.17 Which of the following statements about hormone regulation of the female reproductive cycle is false? a. LH and FSH are produced in the pituitary, and estrogen and progesterone are produced in the ovaries. b. Estradiol and progesterone secreted from the corpus luteum cause the endometrium to thicken. c. Both progesterone and estrogen are produced by the follicles. d. Secretion of GnRH by the hypothalamus is inhibited by low levels of estrogen but stimulated by high levels of estrogen.
Which of the following statements correctly describes the development of the endometrium during the menstrual cycle? Select one: a. Estrogen causes the relatively fast thickening of the endometrium during the follicular stage. Progesterone maintains the thickness of the endometrium during the luteal phase. b. Progesterone causes the relatively slow development of the endometrium during the follicular stage and then accelerates the thickening of the endometrium during the luteal phase. c. Estrogen causes accelerated development of the endometrium during the follicular stage and then maintains the thickness of the endometrium during the luteal phase. d. Estrogen causes the relatively slow development of the endometrium during the follicular stage. Progesterone causes accelerated thickening of the endometrium during the luteal phase.
Although the most effective form of an oral contraceptive for woman contain estrogen and progestin, some birth control pills contain a small dose of progestin-only. This is because there are many risks and side effects. Which of the following statements is NOT a reason for using a progestin-only oral contraceptive? Select one: A. progesterone maintains the corpus luteum as corpus luteum release a large amount of progesterone and estrogen. B. progesterone suppresses the maturation of follicles, thereby preventing ovulation of a mature ovum. C. progestin-only oral contraceptives prevent the production of FSH and LH in the anterior pituitary. D. progesterone suppresses the production of GnRH in the hypothalamus.
Which of the following statements does NOT correctly describe the similarities and differences between male and female reproductive systems? Select one: a. Millions of mature sperm are produced on a daily basis, whereas single mature ovum is released every 28 days. b. Meiosis is completed in eggs after fertilization begins, whereas a mature sperm has completed meiosis prior to fertilization. c. Eggs and sperm contain exactly half of the genetic material of a normal somatic cell. Many zygotes with an abnormal number of genetic material often do not successfully implant. d. Eggs and sperm can survive for 3 to 5 days in the Fallopian tubes.
Which description below explains how the hormones released in birth control pills causes natural ovulation to cease? Select one: a. Birth control pills release estrogen. Estrogen controls the secondary sex characteristics of the female body. b. Birth control pills release progesterone. Progesterone feeds back to the pituitary gland, thereby inhibiting FSH and LH and in effect, stopping the ovarian and menstrual cycle. c. Birth control pills release progesterone. Progesterone causes an increase in FSH, thereby increasing the production of follicles. d. Birth control pills release estrogen. Estrogen feeds back to the posterior pituitary, causing an increase of LH and thereby ceasing the ovarian cycle.
Mumps is a viral infection. The primary symptom of mumps is visible swelling of the parotid gland on either side of the face. However, the virus can also infiltrate the male reproductive system, causing the testes to atrophy. Some effects include oligospermia (low sperm count), azoospermia (no sperm in semen), and asthenospermia (reduced sperm movement). Describe how intrauterine insemination can be used to aid successful fertilization and explain why it helps. Make sure that the treatment process AND how the process helps to improve fertility are clearly explained.
The change of successful fertilization is approximately 18% in every cycle. Why does this statistic seem so low? All of the following statements provide a reason as to why the chance of fertilization is 18% every ovarian cycle EXEPT Select one: A. Some Sperm cells are not very motile, while others are formed without a tail. B. If more than one sperm fertilizes an egg, multiple embryos can result. C. Vagina is very acidic, killing many sperm. D. There two fallopian tubes and two ovaries, but only one of them releases an ovum every cycle.
If one follows 32 primary oocytes in an animal through their various stages of oogenesis, how many secondary oocytes would be formed? How many first polar bodies would be formed? How many ootids would be formed? If one follows 32 primary spermatocytes in an animal through their various stages of spermatogenesis, how many secondary spermatocytes would be formed? How many spermatids would be formed? Secondary oocytes First polar bodies Ootids Secondary Spermatocytes Spermatids