Anatomy Chapter 29

1) The gradual modification of anatomical structures during the period from conception to maturity is A) development. B) differentiation. C) embryogenesis. D) capacitation. E) All of the answers are correct.

2) Proteolytic enzymes that digest a path through the zona pellucida include A) hyaluronidase and hCG. B) hyaluronidase and acrosin. C) acrosin and collagenase. D) relaxin and hyalouronidase. E) acetic acid and hydrochloric acid.

3) Contact of a sperm with the oocyte membrane causes A) oocyte activation. B) completion of the second meiosis. C) extrusion of the second polar body. D) membrane fusion. E) All of the answers are correct.

4) After fertilization, the first cell division is completed A) within a few seconds. B) within the hour. C) about 6 hours later. D) in 12 hours. E) more than a day later.

5) Sperm cannot fertilize an oocyte until they A) undergo capacitation. B) undergo meiosis. C) lose their flagellum. D) are in the vagina for 3 days. E) are activated by sustentacular cells of the vagina.

6) Which of the following is not part of oocyte activation? A) softening of the zona pellucida B) influx of sodium ion C) membrane depolarization D) release of calcium ion from smooth ER E) discharge of exocytotic vesicles

7) Polyspermy results in A) twins. B) fetuses with different fathers. C) haploid individuals. D) chimeric adults. E) a nonfunctional zygote.

8) During amphimixis, A) sperm become haploid. B) the ovum finishes meiosis II. C) the male and female pronuclei fuse. D) meiosis occurs. E) gametes are formed.

9) The site where fertilization normally occurs is in the A) cervix. B) fimbrae. C) uterine wall near the fundus. D) outer one-third of the uterine tube. E) union of the vagina and uterus.

10) The layer of follicle cells that surround the unfertilized egg is called the A) zona pellucida. B) corona radiata. C) Graafian follicle. D) functional zone. E) tunica follicularis.

11) Differentiation among blastomeres is the result of A) enzymes introduced by the sperm. B) hormones produced by the ovum. C) an unequal distribution of regulatory molecules in the cytoplasm of the ovum. D) regulator molecules supplied by cells of the uterus. E) enzymes activated by the sperm.

12) Which of the following statements concerning development is false? A) The term induction refers to the chemical interplay between developing cells. B) The developing oocyte receives molecules that affect development from the surrounding granulosa cells. C) Each blastomere in the blastula receives exactly the same cytoplasmic composition. D) Differences in a cell's cytoplasmic makeup affect the cell's genetic activity. E) Cells release molecules that affect the developmental process of neighboring cells.

13) The developmental period that is the period of all embryological and early fetal development is A) the first trimester. B) the second trimester. C) the third trimester. D) infancy. E) adolescence.

14) During early development, the Y chromosome produces a substance called "testis determining factor" (TDF) that causes the indifferent gonad to become a testis. This would be an example of A) capacitation. B) activation. C) differentiation. D) induction. E) predilection.

15) The period of gestation that is characterized by rapid fetal growth and fat deposition is the ________ trimester. A) first B) second C) third

16) The period of gestation when the rudiments of all major organ systems are established is the ________ trimester. A) first B) second C) third

17) The period of gestation when organs and organ systems complete most of their development and the fetus looks distinctly human is the ________ trimester. A) first B) second C) third

18) The process of cell division that divides the cytoplasm of the zygote among blastomeres is called A) cleavage. B) implantation. C) placentation. D) embryogenesis. E) blastulation.

19) The penetration of the endometrium by the blastocyst is referred to as A) cleavage. B) implantation. C) placentation. D) embryogenesis. E) fertilization.

20) ________ are nearly identical cells that are produced by early cleavages. A) Blastomeres B) Morulas C) Gastrulas D) Amnions E) Blastulas

21) The solid ball of cells that has been likened to a mulberry is called a A) chorion. B) blastula. C) gastrula. D) morula. E) blastocyst.

22) A blastocyst is a(n) A) extraembryonic membrane. B) solid ball of cells. C) hollow ball of cells. D) portion of the placenta. E) origin of the urinary bladder.

23) The inner cell mass of the blastocyst will A) form the placenta. B) form the morula. C) form the embryo. D) form blood vessels of the placenta. E) provide nutrients for early growth.

24) During implantation, the A) trophoblast erodes a path through the endometrium. B) inner cell mass begins to form the placenta. C) maternal blood vessels in the endometrium are walled off from the blastocyst. D) entire trophoblast becomes syncytial. E) inner cell mass is temporarily deprived of nutrients. Answer: A

25) Under the influence of the trophoblast, maternal blood vessels in the endometrium A) disappear. B) attach to the inner cell mass. C) break down and form sinuses or lacunae. D) form a capillary network in the trophoblast. E) increase in size and penetrate the blastocyst.

26) A space opens within the inner cell mass that will form the A) blastocoele. B) lacunae. C) amniotic cavity. D) chorion. E) allantois.

27) The trophoblast has many of the characteristics of ________ cells. A) cardiac B) cancer C) infectious D) rejuvenating E) epithelial

28) By day 12 of embryonic development, mesoderm begins to form through A) embryolization. B) gastrulation. C) mitosis. D) meiosis. E) None of the answers is correct.

29) Shortly after gastrulation, the body and organs of the embryo begin to form. This process is called A) cleavage. B) implantation. C) placentation. D) embryogenesis. E) germination.

30) Which of the following is false concerning the allantois? A) It derives partly from endoderm. B) It projects into the umbilical cord. C) It stores nitrogenous wastes. D) Part will develop as the urinary bladder. E) It acts as the fetal bone marrow.

31) Ectoderm is to ________ as mesoderm is to ________. A) neural tissue; muscle tissue B) cardiovascular system; neural tissue C) mesoderm; endoderm D) neural tissue; epithelial tissue E) muscle tissue; nerve tissue

32) The mesoderm and the trophoblast combine to form the A) amnion. B) amniotic sac. C) chorion. D) allantois. E) inner cell mass.

33) Initially, the nutrients absorbed by the trophoblast easily reach the inner cell mass by simple A) osmosis. B) diffusion. C) peristalsis. D) ciliary action. E) convection.

34) The placenta is a source of which of the following hormones? A) hCG B) relaxin C) placental lactogen D) progesterone E) All of the answers are correct.

35) Which of the following is a critical event of the first trimester? A) cleavage B) implantation C) placentation D) embryogenesis E) All of the answers are correct.

36) During gastrulation, A) the blastomeres fuse. B) the placenta penetrates the endometrium. C) three germ layers are formed. D) cells from the hypoblast move to the epiblast. E) the neural tube closes.

37) The region known as the primitive streak is the site of A) migration of mesodermal cells to form the endoderm. B) endoderm formation. C) ectoderm formation. D) migration of ectodermal cells to form the mesoderm. E) amnion formation.

38) The ectoderm forms A) muscle. B) blood. C) neural tissues. D) the lining of the digestive tract. E) the urinary system.

39) The mesoderm forms A) muscle. B) epidermis. C) the brain. D) the lining of the digestive tract. E) respiratory epithelium.

40) The endoderm forms A) muscle. B) blood. C) neural tissue. D) skin. E) the urinary bladder.

41) The extraembryonic membrane that forms blood is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) decidua.

42) Oxygenated blood from the placenta returns to the fetus in the A) allantois. B) umbilical vein. C) umbilical arteries. D) decidua capsularis. E) umbilical capillaries.

43) Where in the embryo does mesoderm first appear? A) between the cell layers of the inner cell mass B) within the blastocoele C) in the chorionic villi D) above the epiblast E) around the trophoblast

44) The part of the endometrium that covers the implanted embryo and lacks chorionic villi is the A) decidua parietalis. B) decidua albicans. C) decidua functionalis. D) decidua capsularis. E) decidua basalis.

45) Which embryonic germ layer forms the linings of the respiratory and digestive tracts? A) mesoderm B) ectoderm C) trophoderm D) endoderm E) epiderm

46) Which embryonic germ layer forms connective tissues such as bone and cartilage? A) epiderm B) trophoderm C) ectoderm D) mesooderm E) endoderm

47) Which embryonic germ layer forms the brain and spinal cord? A) ectoderm B) endoderm C) trophoderm D) epiderm E) mesooderm

48) The extraembryonic membrane that forms a fluid-filled sac is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) decidua.

49) The extraembryonic membrane that gives rise to the umbilical cord is the A) yolk sac. B) allantois. C) amnion. D) chorion. E) decidua.

50) The extraembryonic membrane that forms the fetal portion of the placenta is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) decidua.

51) The hormone that increases the flexibility of the pubic symphysis during pregnancy is A) luteinizing hormone. B) progesterone. C) human chorionic gonadotropin. D) human placental lactogen. E) relaxin.

52) If fertilization occurs, the ________ is maintained because the embryo secretes ________. A) corpus albicans; human chorionic gonadotrophin B) corpus luteum; luteinizing hormone C) corpus cavernosum; human chorionic gonadotrophin D) corpus luteum; human chorionic gonadotrophin E) corpus albicans; placental prolactin

53) Which of the following is not one of the extraembryonic membranes? A) yolk sac B) amnion C) allantois D) chorion E) umbilical cord

54) The hormone called the hormone of pregnancy, inhibiting uterine contractions, is A) hCG. B) relaxin. C) placental lactogen. D) progesterone. E) All of the answers are correct.

55) In ________, implantation occurs somewhere other than in the uterus. A) ectopic pregnancy B) hydramnios C) placenta previa D) abortion E) spontaneous abortion

56) Which of the following statements about the trophoblast is false? A) It secretes hyalouronidase to erode endometrial cell adhesion. B) It absorbs nutrients released by degenerating endometrial glands. C) It has both an acellular and cellular component. D) It is derived from the inner cell mass. E) It causes maternal blood vessels to break down.

57) Which of these statements about ectopic pregnancy is false? A) The embryo may implant in the uterine tube. B) The mother's life may be endangered. C) Vaginal delivery is often possible. D) It occurs in less than 1 percent of pregnancies. E) It does not yield a viable embryo.

69) Which of the following are recognized classes of abortion? A) spontaneous B) therapeutic C) induced D) spontaneous and induced E) All of the answers are correct.

70) By the end of gestation, maternal blood volume normally increases by almost ________ percent. A) 20 B) 25 C) 50 D) 80 E) 100

71) The prostaglandins produced in the endometrium A) initiate the release of oxytocin for parturition. B) stimulate smooth muscle contractions. C) initiate secretory activity in the mammary glands. D) promote breast development. E) All of the answers are correct.

72) Stretching of the cervix causes an increase in the blood levels of A) estrogen. B) progesterone. C) oxytocin. D) relaxin. E) chorionic gonadotropin.

73) Which of the following does not occur during pregnancy? A) A woman's respiratory rate and tidal volume increase. B) Maternal blood volume increases. C) Maternal nutrient requirements increase. D) A woman's glomerular filtration rate increases. E) A woman's bladder capacity increases.

74) Progesterone calms the myometrium and prevents contraction. What factors antagonize progesterone and trigger labor and delivery? A) Rising estrogen levels increase sensitivity. B) Rising oxytocin levels lead to uterine contractions. C) distortion of the myometrium D) distortion of the cervix E) All of the answers are correct.

75) During gestation, contraction of the myometrium is inhibited by ________, produced by the corpus luteum. A) progesterone B) estrogen C) oxytocin D) prostaglandins E) inhibin

76) The first stage of labor is the ________ stage. A) dilation B) expulsion C) placental D) decidual E) neonate

77) The stage of labor during which the fetus emerges from the vagina is called the ________ stage. A) emergence B) dilation C) placental D) expulsion E) fetal

78) Which of the following does not occur at puberty? A) FSH levels rise. B) GnRH levels decline. C) Levels of sex hormones rise. D) Gametogenesis begins. E) Secondary sexual characteristics begin to develop.

79) As a person ages, A) the skin becomes more elastic. B) lung tissue becomes more elastic. C) peristalsis and muscle tone decrease. D) all hormone levels decrease. E) peristalsis and muscle tone decrease and some hormone levels decrease

80) The infancy stage of life is considered to be over at A) 3 months B) age 2. C) 6 months. D) 1 month. E) 18 months.

81) ________ is the medical specialty that focuses on postnatal development from infancy to adolescence. A) Geriatrics B) Orthopedics C) Pediatrics D) Psychiatrics E) None of the answers is correct.

82) Which of the following activities occurs during senescence? A) decrease in the size of some cell populations B) accumulation of mutations C) reduction in immune response D) reduced mitosis in stem cells E) All of the answers are correct.

83) The neonatal period extends A) for the first 24 hours of life. B) for the first month of life. C) until the first birthday. D) from day 1 until day 60. E) until breast feeding stops.

84) Non-sex chromosomes are called A) homologous. B) homozygous. C) heterozygous. D) autosomal. E) chromatids.

85) If both parents are heterozygous dominant for a trait, what is the probability of an offspring inheriting the recessive trait? A) 10% B) 25% C) 50% D) 75% E) 100%

86) The alternate forms of any one gene are called A) homologous. B) homozygous. C) heterozygous. D) autosomes. E) alleles.

87) If an individual carries a pair of alleles that are the same, the individual is ________ for the trait. A) homologous B) homozygous C) heterozygous D) autosomous E) polygenic

88) If a color-blind (X-linked recessive trait) man marries a woman who is heterozygous for the trait, what proportion of their male offspring can be expected to be color blind? A) 1/2 B) 1/4 C) 1/8 D) 3/4 E) 100 (all)

89) If an individual carries two different alleles for the same trait, the individual is ________ for the trait. A) homologous B) homozygous C) heterozygous D) autosomous E) polygenic

90) If a sperm carrying the "Y" chromosome fertilizes the ovum, the resulting offspring will be A) haploid. B) Rh positive blood type. C) male. D) fraternal twins. E) female.

91) The presence of a recessive gene can be detected (seen) only if the individual is A) homozygous recessive. B) heterozygous dominant. C) heterozygous recessive. D) homozygous dominant. E) epistatic recessive.

92) A woman who is heterozygous for blood type A mates with a man who is homozygous for blood type O. What blood type(s) would their children have? A) 75% heterozygous type A B) 100% type A C) 75% homozygous type O D) 100% type O E) 50% type A, 50% type O

93) The gene for normal skin pigment (A) can also code for the recessive trait of albinism (a). An albino man and a homozygous normal pigmented woman marry and have four children. What is the phenotype of the children? A) 75% normal skin pigment and 25% albino B) 100% normal skin pigment C) 50% normal skin pigment and 50% albino D) 100% normal skin pigment E) 100% albino

94) In simple autosomal inheritance, phenotypic characters are determined, or controlled, by A) a single pair of alleles. B) multiple alleles. C) the action of a single gene. D) regulator genes on a different chromosome. E) the genes on the Y chromosome.

95) In polygenic inheritance, phenotypic characters are A) determined by a double pair of alleles. B) determined by interactions among several genes. C) determined by multiple copies of a single gene. D) always controlled by genes on the same chromosome. E) determined by the genes on the Y chromosome.