Chapter 23

1. Human prenatal development takes ___ weeks. A. 28 B. 32 C. 38 D. 44

2. The postnatal period extends from A. the fertilized egg until the end of life. B. fertilization to birth. C. birth to death. D. the beginning of the fetal period until the beginning of childhood

3. Fertilization usually occurs in the A. ovary. B. uterine tube. C. uterus. D. vagina

4. Muscle contractions of the uterine walls and ________ in the semen aid sperm cell movement through the uterus and uterine tubes. A. estrogen B. progestins C. prostaglandins D. epinephrine

5. An enzyme that sperm secretes that is important for egg penetration is A. hyaluronidase B. collagenase C. peptidase D. acetylcholinesterase

6. The nuclei from the approaching sperm and egg are called A. prenuceli B. mononuclei C. pronuclei D. gametocytes.

7. At the blastocyst stage, the cells are considered A. totipotent. B. extraembryonic. C. pluripotent. D. endodermal.

8. Embryonic stem cells are derived from the A. outer cell mass of the morula. B. inner cell mass of the blastocyst. C. middle layer of the zygote. D. trophoblast.

9. Which of the following layers is considered loosely organized connective tissue? A. Mesoderm B. Endoderm C. Ectoderm D. Epidermis

10. Compared to adult hemoglobin, fetal hemoglobin A. binds iron more strongly. B. has more hemoglobin subunits. C. binds oxygen more readily. D. has more heme units.

12. Labor is regulated by A. negative feedback control. B. positive feedback control. C. prolactin. D. estrogen.

13. The fetus is protected from certain infections, to which the mother is immune, by A. antibodies from the mother's immune system. B. antibodies from its own immune system. C. its own innate defenses. D. the extraembryonic membranes.

14. The hormones that maintain the uterine wall during the last 5 to 6 months of pregnancy are A. FSH and LH. B. human chorionic gonadotropin and synthetic estrogen. C. placental lactogen and relaxin. D. placental estrogen and progesterone

15. The hormone oxytocin aids the birth process by stimulating A. fetal muscular movements. B. uterine wall contractions. C. an increase in progesterone secretion. D. an increase in estrogen secretion.

16. The hormone measured in a pregnancy test is A. estrogen. B. progesterone. C. hCG. D. ADH.

17. The cells of a blastocyst that help form the chorion constitute the A. blastomere. B. inner cell mass. C. trophoblast. D. zona pellucida

18. The placental membrane is composed of A. the embryonic disc. B. a single layer of epithelial cells. C. a double layer of epithelial cells. D. the amnion and chorion.

24. The placenta is composed of tissues from the A. mother only. B. embryo only. C. mother and embryo. D. chorion only.

25. Which of the following is (are) true in regard to the fetal stage of development? A. It begins 8 weeks after fertilization. B. The organ systems are mostly formed, although immature. C. The head is disproportionately large compared to the rest of the body at the beginning of the stage. D. All of the above

27. Which of the following adult structures is not derived from the same primary germ layer as the others? A. nerves B. blood vessels C. muscles D. bones

28. The external genitalia of the fetus can be distinguished as male or female by about ___ weeks after fertilization. A. 3 B. 6 C. 12 D. 24

32. A blastomere is a _____ and a blastocyst is _____. A. hollow ball of cells; a cell resulting from cleavage B. fetal organ produced by cleavage; an embryonic organ produced by cleavage C. fetal membrane; an embryonic membrane D. cell produced by cleavage; a hollow ball of cells

33. The inner cell mass A. helps form the placental membrane. B. helps form the amnion. C. helps form the chorion. D. gives rise to the embryo.

34. The implantation of the blastocyst results from A. enzymes digesting the endometrium around the blastocyst. B. hyaluronic acid breaking down the myometrium around the blastocyst. C. hCG stimulating the growth of trophoblast blood vessels. D. the cessation of the reproductive cycle.

35. Which of the following is a function of hCG? A. It breaks down the corpus luteum. B. It helps protect the blastocyst against being rejected. C. It prevents the developing placenta from secreting hormones. D. It stimulates the release of enzymes that enable the blastocyst to implant into the endometrium

36. During the embryonic stage, the primary germ layers develop from the A. placenta. B. blastocyst. C. embryonic disc. D. morula.

37. The major body part(s) derived from ectoderm is/are A. nervous system and skin. B. muscle tissue. C. bone tissue. D. liver and pancreas

38. The major body parts derived from endoderm are the epithelial lining of the A. digestive tract. B. respiratory tract. C. urinary bladder. D. all of the above.

39. The major body parts derived from mesoderm are the A. nervous system and sense organs. B. muscle tissue, bone tissue, and bone marrow. C. epidermis, hair, nails, and glands of skin. D. respiratory tract, urinary bladder, and urethra

40. The placenta allows A. oxygen and nutrients to diffuse from maternal blood to the embryo. B. carbon dioxide and other wastes to diffuse from the maternal blood to the embryonic blood. C. maternal blood to mix with fetal blood. D. the fetus to enlarge without rupturing the mother's abdomen.

42. Amniotic fluid A. stores nutrients for the fetus. B. absorbs wastes the fetus excretes. C. protects the embryo against being jarred by movements. D. provides nutrients to the fetus from the maternal part of the placenta.

43. The yolk sac A. forms blood cells in early development. B. provides nutrients to the fetus when the umbilical cord is disconnected. C. stores metabolic wastes until the fetus is born. D. gives rise to the primary germ layers

44. The term newborn refers to the period from birth through _____, whereas the term infant refers to the period from _____. A. 3 months; 3 months to 6 months B. the first four weeks; the first month to 1 year C. one week; the second week through the second year D. the first year; the first year to the second year

45. Which of the following factors stimulates a newborn's first breath? A. Increasing concentration of carbon dioxide B. Decreasing pH C. Low oxygen concentration D. All of the above

46. Following birth, the infant's metabolic rate A. increases and its oxygen consumption increases. B. increases and its oxygen consumption decreases. C. decreases and its oxygen consumption increases. D. decreases and its oxygen consumption decreases.

47. Which of the following provides the main source of energy for a newborn during its first few days? A. Glucose B. Glycogen C. Fat D. Protein

48. After birth, the foramen ovale is closed as a result of A. increasing pressure in the right atrium. B. increasing pressure in the left atrium. C. increased resistance in the pulmonary circuit. D. decreased blood volume in the pulmonary veins.

50. Which of the following is not a characteristic of childhood? A. Secondary teeth replacing primary teeth B. Becoming reproductively functional C. Establishing bowel control D. Developing a high degree of voluntary muscular control

51. As a rule, during adulthood A. skeletal muscles tend to lose strength. B. the circulatory system becomes less efficient. C. the skin becomes less elastic. D. all of the above.

52. The period of preactive dying takes A. up to six months. B. up to three months. C. about a month. D. two weeks for cancer, two months for heart disease

53. Changes that occur as death approaches include A. limbs become cool and numb. B. accumulation of secretions in the respiratory tract. C. blood pressure falls. D. all of the above.

65. Single genes that are important in determining how long a person lives affect A. glucose and lipid metabolism. B. cell cycle control. C. immune system functioning and response to stress. D. all of the above.

66. Development is a continuous process and includes growth. True False

67. Progesterone in semen stimulates the movement of sperm cells. True False

68. Proteolytic enzymes from the trophoblast aid implantation of an embryo. True False

69. The umbilical cord contains two umbilical veins. True False

70. The fetal stage of development begins at the end of the eighth week. True False

71. Factors that can cause congenital malformations by affecting an embryo during its periods of rapid growth and development are called teratogens. True False

72. The ductus arteriosus allows fetal blood to bypass the lungs. True False

73. In a fetus, the umbilical arteries arise from the renal arteries. True False

74. The neonatal period of development extends from birth to the end of one year. True False

75. The primary function of surfactant is to increase surface tension in the newborn's lungs. True False

76. After birth, the ductus arteriosus constricts and becomes the ligamentum arteriosum. True False

77. Some factors that help to stimulate the newborn's first breath are increasing CO2 , decreasing pH, decreasing O2 , decreasing body temperature, and mechanical stimulation. True False

78. The adolescent period begins at the end of the first year and completes at puberty. True False