Chapter 29 TB
The epidermis and accessory structures of skin form from which germ layer? A) endoderm B) mesoderm C) epiderm D) ectoderm E) trophoderm
D) ectoderm
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.
D) embryogenesis.
Which embryonic germ layer forms the linings of the respiratory and digestive tracts? A) mesoderm B) ectoderm C) trophoderm D) endoderm E) epiderm
D) endoderm
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
D) expulsion
The term ________ refers to the time spent in prenatal development. A) transformation B) micturition C) parturition D) gestation E) cleavage
D) gestation
Immediately after birth, a newborn's health is assessed by an Apgar score. Which of the following is not part of the Apgar assessment? A) heart rate B) breathing C) muscle tone D) hearing E) skin color
D) hearing
The primary nutrient source for early embryonic development that later becomes an important site for blood formation is the A) amniotic fluid. B) placenta. C) basal decidua. D) umbilical vein. E) yolk sac.
E) yolk sac.
The cell that directly results from the fusion of a secondary oocyte and a single sperm is called a(n) A) ootid. B) gastrula. C) blastula. D) morula. E) zygote.
E) zygote.
By the end of gestation, maternal blood volume normally increases by almost ________ percent. A) 20 B) 25 C) 50 D) 80 E) 100
C) 50
Block to polyspermy is prevented by the ________ reaction. A) metabolic B) gamete C) gollumina D) cortical E) polarity
D) cortical
Twins that occur when blastomeres separate are called A) monozygotic. B) blastulatory. C) zygoblastic. D) dizygotic. E) fraternal.
A) monozygotic.
The mesoderm forms A) muscle. B) epidermis. C) the brain. D) the lining of the digestive tract. E) respiratory epithelium
A) muscle.
An infant born ________ prematurely has a good chance of survival. A) 1.5 months B) 3 months C) 4 months D) 5 months E) 6 months
A) 1.5 months
________ are nearly identical cells that are produced by early cleavages. A) Blastomeres B) Morulas C) Gastrulas D) Amnions E) Blastulas
A) Blastomeres
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
A) between the cell layers of the inner cell mass
The processes that occur in the pre-embryonic period are A) cleavage and implantation. B) cleavage and placentation. C) implantation and placentation. D) implantation and embryogenesis. E) placentation and embryogenesis.
A) cleavage and implantation.
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.
A) cleavage.
The formation of different types of cells required in development, or ________, occurs through selective changes in genetic activity. A) differentiation B) cupellation C) deployment D) gametogenesis E) phylogeny
A) differentiation
The first stage of labor is the ________ stage. A) dilation B) expulsion C) placental D) decidual E) neonate
A) dilation
Which embryonic germ layer forms the brain and spinal cord? A) ectoderm B) endoderm C) trophoderm D) epiderm E) mesooderm
A) ectoderm
In ________, implantation occurs somewhere other than in the uterus. A) ectopic pregnancy B) hydramnios C) placenta previa D) abortion E) spontaneous abortion
A) ectopic pregnancy
The process by which a viable embryo is formed is called A) embryogenesis. B) organogenesis. C) gametogenesis. D) morphogenesis. E) blastogenesis.
A) embryogenesis
In a(n) ________, an incision is made in the perineal musculature. A) episiotomy B) lumbar puncture C) crowning D) epidural E) peritoneal cut
A) episiotomy
The uterine epithelium is broken down by the enzyme, A) hyaluronidase. B) acrosin. C) urase. D) proteoglycan. E) relaxin.
A) hyaluronidase.
A mother has a lot of milk stored in the breast and mammary glands but cannot seem to expel the milk for her newborn. Her doctor thinks that the cause may be A) low levels of oxytocin. B) high levels of HCG. C) low levels of estrogen. D) low levels of progesterone. E) unresponsive smooth muscle around the mammary glands
A) low levels of oxytocin.
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; neural tissue
A) neural tissue; muscle tissue
Mammary gland development requires a combination of all of the following hormones, except A) oxytocin. B) placental prolactin. C) prolactin. D) human placental lactogen. E) estrogen.
A) oxytocin.
During gestation, contraction of the myometrium is inhibited by ________, produced by the corpus luteum. A) progesterone B) estrogen C) oxytocin D) prostaglandins E) inhibin
A) progesterone
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 adjacent to the oocyte membrane
A) softening of the zona pellucida
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.
A) the first trimester.
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.
A) trophoblast erodes a path through the endometrium.
The ________ is formed by the allantois, blood vessels, and yolk sac. A) umbilical cord B) chorion C) chorioallantoic membrane D) trophoblast E) amnion
A) umbilical cord
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.
A) undergo capacitation.
The extraembryonic membrane that forms blood is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) decidua.
A) yolk sac.
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.
B) GnRH levels decline.
The developmental period heralded by the onset of puberty is known as A) post-infancy. B) adolescence. C) early childhood. D) teenage years. E) pre-teen.
B) adolescence.
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.
B) age 2.
The umbilical cord contains the yolk sac, the placental blood vessels and the A) chorionic villi. B) allantois. C) amnion. D) chorion. E) decidua.
B) allantois.
The extraembryonic membrane that forms a fluid-filled sac is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) decidua.
B) amnion.
The almost identical cells produced by cleavage divisions are called A) centromeres. B) blastomeres. C) telomeres. D) myosomes. E) somal cells.
B) blastomeres.
The clear liquid secreted by the mammary glands before milk production begins is called A) milk. B) colostrum. C) serum. D) plasma. E) peritoneal.
B) colostrum.
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.
B) corona radiata.
The inner cellular layer of trophoblast that remains intact inside the blastocyst is termed the A) morula. B) cytotrophoblast. C) synctiotrophoblast. D) lacunae. E) amnion.
B) cytotrophoblast.
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) for the first six months. E) until breast feeding stops.
B) for the first month of life
Sperm release ________ to break down the bonds between adjacent follicle cells surrounding the oocyte. A) relaxin B) hyaluronidase C) calcium D) zonal inhibiting proteins E) glucose
B) hyaluronidase
The penetration of the endometrium by the blastocyst is referred to as A) cleavage. B) implantation. C) placentation. D) embryogenesis. E) fertilization
B) implantation.
Adolescence begins at the period of sexual maturity called A) menopause. B) puberty. C) senescence. D) postnatal. E) gestation.
B) puberty.
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
B) second
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) stimulate the milk let-down reflex.
B) stimulate smooth muscle contractions.
Fraternal twins result from A) one egg that is fertilized by two different sperm. B) two different zygotes. C) one zygote that splits into two zygotes. D) two eggs fertilized by one sperm cell. E) a blastula that splits into two blastulas.
B) two different zygotes.
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.
B) umbilical vein.
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 blastocyst 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.
C) Each blastomere in the blastocyst receives exactly the same cytoplasmic composition.
________ is the medical specialty that focuses on postnatal development from infancy to adolescence. A) Geriatrics B) Orthopedics C) Pediatrics D) Psychiatrics E) Obstetrics
C) Pediatrics
During the second trimester, the mesoderm on the outer surface of the amnion contacts the mesoderm on the inner surface of the chorion and fuse to form the ________ membrane. A) cervical B) syncytial C) amniochorionic D) embryonic E) umbilical
C) amniochorionic
A space opens within the inner cell mass that will form the A) blastocoele. B) lacunae. C) amniotic cavity. D) chorion. E) allantois.
C) amniotic cavity.
The hollow cavity within the blastocyst is the A) blastula. B) gastrula. C) blastocoele. D) trophoblast. E) ootid.
C) blastocoele.
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.
C) break down and form sinuses or lacunae.
The mesoderm and the trophoblast combine to form the A) amnion. B) amniotic sac. C) chorion. D) allantois. E) inner cell mass.
C) chorion.
The gradual modification of anatomical structures and physiologic characteristics from fertilization to maturity is termed A) gametogenesis. B) ontogeny. C) development. D) transformation. E) disablement.
C) development.
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.
C) form the embryo.
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.
C) hollow ball of cells.
The transfer of genetically determined characteristics from generation to generation is termed A) development. B) differentiation. C) inheritance. D) phylogeny. E) maturity.
C) inheritance.
The ectoderm forms A) muscle. B) blood. C) neural tissues. D) the lining of the digestive tract. E) the urinary system.
C) neural tissues.
Stretching of the cervix causes an increase in the blood levels of A) estrogen. B) progesterone. C) oxytocin. D) relaxin. E) chorionic gonadotropin.
C) oxytocin.
The goal of labor is childbirth, also termed A) gestation. B) development. C) parturition. D) abortion. E) senescence.
C) parturition.
The uterine epithelium is broken down by which structure of the blastocyst? A) allantois B) cytotrophoblast C) syncytiotrophoblast D) blastocoele E) amnion
C) syncytiotrophoblast
The embryo becomes a fetus at A) the end of the first week. B) the end of the second week. C) the end of the eighth week. D) the end of the second trimester. E) the end of the third trimester.
C) the end of the eighth week.
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.
C) the male and female pronuclei fuse.
The period of gestation that is characterized by rapid fetal growth and fat deposition is the ________ trimester. A) first B) second C) third
C) third
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
C) three germ layers are formed.
Blood flows from the fetus to the placenta through paired A) umbilical vein. B) iliac veins. C) umbilical arteries. D) uterine veins. E) uterine arteries.
C) umbilical arteries.
Uterine contractions that are irregular and brief that occur toward the end of gestation are called A) parturition. B) expulsion. C) true labor. D) Braxton-Hicks. E) dilation.
D) Braxton-Hicks.
Which of the following statements about the first trimester is false? A) The events that occur during the first trimester are very complex. B) Only about 40 percent of conceptions survive the first trimester. C) During this trimester, cleavage, implantation, placentation and embryogenesis occur. D) The fetus gains the most weight during the first trimester. E) It consists of 10 developmental weeks.
D) The fetus gains the most weight during the first trimester.
The separation between the inner cell mass and the trophoblast forms a fluid-filled chamber called the A) chorion. B) yolk sac. C) allantois. D) amniotic cavity. E) placenta.
D) amniotic cavity.
Placental functions are concentrated in a disc-shaped area in the endometrium called the A) trophoblast. B) allantois. C) capsular decidua. D) basal decidua. E) parietal decidua.
D) basal decidua
The part of the endometrium that covers the implanted embryo and lacks chorionic villi is the A) parietal decidua. B) albicans decidua. C) functional decidua. D) capsular decidua. E) basal decidua
D) capsular decidua.
The extraembryonic membrane that forms the fetal portion of the placenta is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) decidua.
D) chorion.
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
D) corpus luteum; human chorionic gonadotrophin
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.
D) induction.
The period from 1 month after birth to 1 year is known as A) childhood. B) post-fetal. C) neogen. D) infancy. E) neonatal.
D) infancy.
Which embryonic germ layer forms connective tissues such as bone and cartilage? A) epiderm B) trophoderm C) ectoderm D) mesooderm E) endoderm
D) mesooderm
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.
D) migration of ectodermal cells to form the mesoderm
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.
D) morula.
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.
D) outer one-third of the uterine tube.
Fertilization stimulates the oocyte to enter meiosis II and the fertilized oocyte is called a(n) A) oogonium. B) primary oocyte. C) secondary oocyte. D) ovum. E) polar body.
D) ovum.
The hormone called the hormone of pregnancy, inhibiting uterine contractions, is A) hCG. B) relaxin. C) placental lactogen. D) progesterone. E) luteinizing hormone.
D) progesterone.
Which of the following is not one of the extraembryonic membranes? A) yolk sac B) amnion C) allantois D) chorion E) umbilical cord
E) umbilical cord
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
E) A woman's bladder capacity increases
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.
E) It acts as the fetal bone marrow.
Polyspermy results in A) twins. B) fetuses with different fathers. C) haploid individuals. D) chimeric adults. E) a nonfunctional zygote.
E) a nonfunctional zygote.
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) about 30 hours later.
E) about 30 hours later.
Which of the following places the stages of labor in the correct order? A) placental, expulsion, dilation B) placental, dilation, expulsion C) expulsion, dilation, placental D) dilation, placental, expulsion E) dilation, expulsion, placental
E) dilation, expulsion, placental
The placenta is a source of all of the following hormones, except A) hCG. B) relaxin. C) placental lactogen. D) progesterone. E) luteinizing hormone.
E) luteinizing hormone.
The ________ is the portion of the endometrium not in contact with the chorion. A) trophoblast B) allantois C) capsular decidua D) functional decidua E) parietal decidua
E) parietal decidua
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.
E) peristalsis and muscle tone decrease and some hormone levels decrease.
The processes that occur in the embryonic period are A) cleavage and implantation. B) cleavage and placentation. C) implantation and placentation. D) implantation and embryogenesis. E) placentation and embryogenesis.
E) placentation and embryogenesis.
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.
E) relaxin.
The endoderm forms A) muscle. B) blood. C) neural tissue. D) skin. E) the urinary bladder.
E) the urinary bladder.
The human gestation period consists of A) fertilization and one trimester. B) two trimesters of 1 month each. C) three trimesters of 1 month each. D) two trimesters of 2 months each. E) three trimesters of 3 months each.
E) three trimesters of 3 months each.
The outer layer of the blastocyst that can penetrate the endometrium is the A) archegonium. B) chorion. C) gastrula. D) blastula. E) trophoblast.
E) trophoblast.