Anatomy & Physiology Exam 7: Ch. 28 & 29

Conceptus is a term used to describe the developing human offspring.
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Terms in this set (103)
Conceptus is a term used to describe the developing human offspring.
True
The period from fertilization through week eight is called the embryonic period.
True
Fertilization occurs while the egg is still in the ovarian follicle.
False
Freshly deposited sperm are not capable of penetrating an oocyte.
True
By 72 hours after fertilization, the egg has divided into more than 160 cells and is called the morula.
False
Implantation begins six to seven days after ovulation.
True
A pregnancy test involves antibodies that detect GH levels in a woman's blood or urine.
False
The body systems of the developing embryo are present in at least rudimentary form at eight weeks.
True
Of the three germ layers, the mesoderm forms the most body parts.
True
A pregnant woman urinates more often than usual because the uterus compresses the bladder, and she must also dispose of fetal metabolic wastes.
True
The "fluid-filled, hollow ball of cells" stage of development is the blastocyst.TrueThe embryo is directly enclosed in and protected by the amnion.TrueIn fetal circulation, one way in which blood bypasses the nonaerated lungs is by way of the foramen ovale.TrueAn episiotomy is an incision made to widen the vaginal orifice, aiding fetal expulsion.TrueThe placenta and its attached fetal membranes are collectively called the afterbirth.TrueHuman placental lactogen initiates labor.FalseSurfactant production in premature infants is rarely a factor in providing normal respiratory activity.FalseA blastocyst is a hollow ball of cells, while the morula is a solid ball of cells.TrueA zygote is usually formed within the uterus.FalseWhen two genes are on the same chromosome, they are considered linked.TrueThe X chromosome is considerably larger than the Y chromosome.TrueSome segments of the Y chromosome have no counterpart on the X chromosome.TrueThe same allele can have a different effect depending on which parent it comes from.TrueAlleles may code for alternative expressions of a genetic trait.TrueHemophilia is an X-linked condition caused by a recessive gene.TrueEnvironmentally produced phenotypes that mimic conditions that may be caused by genetic mutation are called phenocopies.TrueMost genetic disorders are inherited through dominant genes.FalseA Punnett square is a diagram that may be used to figure out the possible combinations of genes for a traitTrueThe term lethal dominant gene indicates that the gene causes death only when the individual is homozygous.FalseIn incomplete dominance, the heterozygote has a phenotype intermediate between that of homozygous-dominant and homozygous-recessive individuals.TrueGenetic segregation implies that the members of the allele pair determining each trait are distributed to different gametes during meiosis.FalseGenetic variation results from the crossing over and exchange of chromosomal parts that occur during meiosis II.FalseSmall RNAs control the timing of programmed cell death during development.TrueMitochondrial genes are free of errors. As a result, all genetic problems are due exclusively to nuclear genes.FalseIt is possible for a baby to have type O blood if neither parent is type O.TrueThe first "milk" the mother produces is called colostrum.TrueAs the newborn suckles, the mother's pituitary produces oxytocin to assist in releasing milk.FalseThe act of giving birth is called parturition.TrueThe trophoblast cells of the blastocyst will take part in placental formation.TrueMesenchyme is a tissue with star-shaped cells that are free to migrate widely throughout the embryo.TrueA buildup of carbon dioxide in the baby's blood excites respiratory control centers in the baby's brain and triggers the first inspiration.TrueBraxton-Hicks contractions are the weak, irregular uterine contractions resulting from estrogen mediated formation of oxytocin receptors in the myometrium. As a result, the myometrium becomes increasingly irritable, resulting in weak, irregular contractions.TrueDescribe the events allowing monospermy.A sperm entering the oocyte causes ionic calcium to be released into the oocyte cytoplasm, activating the oocyte and preparing it for cell division. This also causes the cortical granules to spill their contents into the extracellular space beneath the zona pellucida. Enzymes from the cortical granulus destroy sperm receptors, preventing further sperm entry. This spilled material binds with water, and as it swells, detaches all sperm still in contact with the oocyte membrane.The result of polyspermy in humans is ________. A) multiple births B) a nonfunctional zygote C) interruption of meiosis D) mitotic insufficiencya nonfunctional zygoteIt is impossible for sperm to be functional (able to fertilize the egg) until after ________. A) the tail disappears B) they become spermatids C) they undergo capacitation D) they have been stored in the uterus for several daysthey undergo capacitationMilk ejection or letdown reflex is stimulated by which of the following hormones associated with pregnancy? A) inhibin B) oxytocin C) prolactin D) gonadotropinoxytocinEstrogen and progesterone maintain the integrity of the uterine lining and prepare the mammary glands to secrete milk. Which of the following structures makes this possible during the first three months of pregnancy? A) the amnion B) the chorion C) corpus luteum D) corona radiatacorpus luteumRelaxin is a hormone produced by the placenta and ovaries. The function of this hormone is to ________. A) block the pain of childbirth B) ensure the implantation of the blastula in the endometrium C) relax/soften the fibrocartilage of the pubic symphysis D) prevent morning sicknessrelax/soften the fibrocartilage of the pubic symphysisThe formation of endodermal and ectodermal germ layers occurs at ________. A) fertilization B) cleavage C) gastrulation D) blastula formationgastrulationWhich hormone maintains the viability of the corpus luteum? A) estrogen B) progesterone C) human chorionic gonadotropin D) human placental lactogenhuman chorionic gonadotropinWhich of the following is a highly unlikely method of producing a child? A) embryo transfer B) ectopic implantation C) in vitro fertilization D) gamete intrafallopian transferectopic implantationWhich of the following is not a correct matching of a fetal structure with what it becomes at birth? A) foramen ovalefossa ovalis B) ductus arteriosusligamentum arteriosum C) ductus venosusligamentum venosum D) umbilical arteriesmedial umbilical ligaments E) All of the above are correctductus arteriosusligamentum arteriosumThe umbilical arteries carry ________. A) waste products to the placenta B) oxygen and food to the fetus C) oxygen and metabolic wastes to the placenta D) oxygen and waste products to the fetuswaste products to the placentaThe correct sequence of preembryonic structures is ________. A) zygote, blastocyst, morula B) zygote, morula, blastocyst C) blastocyst, morula, zygote D) morula, zygote, blastocystblastocyst, morula, zygoteApgar scoring is a way to evaluate newborn vitality and adaptation to its new environment. Which of the following is not assessed as part of the Apgar score? A) heart rate B) respiration C) muscle tone D) temperaturetemperatureThe hormone most concerned with events of lactation is ________. A) estrogen B) oxytocin C) progesterone D) hCGoxytocinInitially, the implanted embryo obtains its nutrition by ________. A) simple diffusion of nutrients from the uterine secretions B) nutrient stores in the embryonic cells C) the blood supply of the placenta D) digestion of endometrial cellsdigestion of endometrial cellsOnset of labor may be a result of all of the following factors except ________. A) secretion of oxytocin B) high estrogen levels C) aspirin and similar drugs D) contraction-related increased emotional and physical stressaspirin and similar drugsSelect the correct statement about fertilization. A) Both spermatozoa and the ovulated secondary oocyte remain viable for about 72 hours in the female reproductive tract. B) Millions of sperm cells are destroyed by macrophages & the vagina's acidic environment. C) If estrogen is present, the pathway through the cervical opening is blocked from sperm entry. D) Once inside the uterus, most sperm cells are protected and remain viable.Millions of sperm cells are destroyed by macrophages & the vagina's acidic environment.The dorsal surface cells of the inner cell mass pile up and take on a distinctive grooved configuration, the ________. A) embryonic disc B) neural crest C) primitive streak D) notochordprimitive streakMuscle tissue is formed by the ________. A) mesoderm B) ectoderm C) endoderm D) epidermmesodermNeural tissue is formed by the ________. A) epiderm B) endoderm C) mesoderm D) ectodermectodermThe trophoblast is primarily responsible for forming the ________. A) allantois B) archenteron C) placental tissue D) yolk sacplacental tissueThe cardiovascular system of a newborn must adjust after the infant takes its first breath, so which of the following is true? A) The foramen ovale between the atria of the fetal heart closes at the moment of birth. B) The ductus venosus is disconnected at the severing of the umbilical cord and all visceral blood goes into the vena cava. C) Renal artery sphincters open to initiate renal blood flow and urine formation. D) Blood no longer bypasses the lungs through the ductus arteriosus & foramen ovale.Blood no longer bypasses the lungs through the ductus arteriosus & foramen ovale.Sperm disperse in the uterus through uterine contractions and the energy of their own flagella. What other factor is involved in sperm movement into the fallopian tube? A) acrosomal membrane softening B) reverse peristalsis of the uterus and uterine tubes C) the cilia on the apex of the cells lining the endometrium D) the increased temperature in the vagina, which stimulates sperm motilityreverse peristalsis of the uterus and uterine tubesAt which stage of labor is the "afterbirth" expelled? A) dystocia B) expulsion C) placental D) full dilationplacentalWhich hormone is not produced by the placenta? A) human placental lactogen B) human chorionic thyrotropin C) relaxin D) inhibininhibinDuring which stage of labor is the fetus delivered? A) dilation stage B) expulsion stage C) placental stage D) gastrula stageexpulsion stageImplantation of the blastocyst is the result of all of the following except ________. A) endometrial phagocytosis of the trophoblast cells B) proteolytic enzymes produced by the trophoblast cells C) settling of the blastocyst onto the prepared uterine lining D) adherence of the trophoblast cells to the endometriumendometrial phagocytosis of the trophoblast cellsCleavage as part of embryonic development is distinctive because it involves ________. A) cell division by mitosis with little or no growth between successive divisions B) the fusion of gametes C) splitting the cell into two separate cells D) meiosiscell division by mitosis with little or no growth between successive divisionsWhich of the following is true in reference to what may pass through the placental barriers? A) nutrients and respiratory gases only B) hormones, maternal blood cells, and nutrients C) nutrients, respiratory gases, wastes, hormones, and alcohol D) respiratory gases, hormones, nutrients, and fetal blood cellsnutrients, respiratory gases, wastes, hormones, and alcoholWhich of the following is not usually considered a teratogen? A) aspirin B) wine C) thalidomide D) German measlesaspirinDerivatives of the ectoderm include ________. A) serosae of the ventral body cavity B) epithelium of the reproductive tract C) epithelium of the pineal and pituitary glands D) connective tissuesepithelium of the pineal and pituitary glandsDerivatives of the mesoderm include ________. A) all nervous tissue B) endothelium of blood and lymph vessels C) glandular derivatives of the digestive tract D) epithelium of the digestive tractendothelium of blood and lymph vesselsDerivatives of the endoderm include ________. A) epithelium of the respiratory tract B) synovial membranes of the joints C) blood, bone marrow, and lymphoid tissue D) organs of the urogenital systemepithelium of the respiratory tractWhich of the choices below occurs if fertilization of the ovum occurs and implantation takes place? A) The corpus luteum is maintained until the placenta takes over its hormone-producing functions. B) The corpus luteum degenerates and becomes the corpus albicans. C) The ovarian cycle begins. D) Increased levels of FSH will be produced.The corpus luteum is maintained until the placenta takes over its hormone-producing functions.Select the correct statement about the special fetal blood vessels. A) The distal parts of the umbilical arteries form the superior vessicle arteries. B) The fossa ovalis becomes the foramen ovale. C) The umbilical vein becomes the ligamentum teres. D) The hepatic portal vein forms from the umbilical artery.The umbilical vein becomes the ligamentum teres.Which of the following statements about the events of fertilization is not true? A) The two pronuclei divide. B) The head of the sperm forms the male pronucleus. C) The secondary oocyte completes the second meiotic division. D) Proteases & acrosin proteinases of sperm disperse the corona radiata cells of the oocyte.The two pronuclei divide.The decidua basalis is ________. A) destined to remain in the uterus after the birth of the infant B) located between the developing embryo and the myometrium C) not a maternal contribution to the placenta D) the tissue that surrounds the uterine cavity face of the implanted embryolocated between the developing embryo and the myometriumCompared with cow's milk, all are true of human milk except: A) has fats & iron that are better absorbed. B) contributes interferon and antibodies to the fetus C) is less satisfying to the infant D) is a good natural laxativeis less satisfying to the infantTwo alleles expressing exactly the same information for a trait are designated as ________. A) hemizygous B) monogamous C) heterozygous D) homozygoushomozygousDominant alleles are so called because under most circumstances they ________. A) code only for tallness and dark skin B) suppress the expression of other alleles C) code for genes that are never considered lethal D) code for most phenotypic and genotypic expressions of a traitsuppress the expression of other allelesRecessive genes are usually expressed in humans only when ________. A) they are coding for skin color B) they are coding for genetic diseases C) the organism is in the embryonic stage D) both alleles are exactly the same, or homozygousboth alleles are exactly the same, or homozygousThose characteristics that can be determined on superficial inspection of an individual are known as ________. A) genotypic B) polygenic C) polyspermic D) phenotypicphenotypicIs genetic diversity due entirely to inherited genes on the sex chromosomes? A) Yes, because the female has two X chromosomes and the male has only one X chromosome. B) Yes, because the male has a Y chromosome. C) Yes, because genetic diversity is due to the Y influence on the autosomes. D) No, because genetic diversity has nothing to do with the sex chromosomes but is due to crossing-over of chromosomes and independent assortment of chromosomes.No, because genetic diversity has nothing to do with the sex chromosomes but is due to crossing-over of chromosomes and independent assortment of chromosomes.A female infant is born with several hundred oocytes, each one genetically unique. This is due to ________. A) mutation B) recessive inheritance C) chromosome deletion D) independent assortment and random crossoverindependent assortment and random crossoverIn meiosis the spermatozoa that are produced are genetically unlike each other and unlike the cell that produces them. This is one reason for the great variation among humans. What causes this effect? A) crossing-over only B) crossing-over and chromosome segregation C) chromosome segregation and independent assortment D) crossing-over and independent assortmentcrossing-over and independent assortmentThe reason recessive genetic disorders are more frequent than disorders inherited as dominant is that ________. A) dominant genetic disorders are never expressed in males B) people carrying dominant genetic disorders always die before birth C) carriers may be unaffected and yet pass defective genes to their offspring D) recessive genetic disorders are limited to persons of the same ethnicitycarriers may be unaffected and yet pass defective genes to their offspringThe gene responsible for the condition known as sickle-cell anemia demonstrates ________. A) incomplete dominance B) a dominant genetic disorder C) a sex-linked genetic disorder D) a recessive genetic disorderincomplete dominanceAn example of multiple-allele inheritance is ________. A) the ABO blood group B) the appearance of freckles on the skin C) the appearance of birthmarks on the skin D) hair that seems to have several shades of a colorthe ABO blood groupWhich of the following is true concerning environmental influence on genetic expression? A) It is impossible to alter in any way the expression of a gene in humans. B) The only time a gene can be influenced by environmental factors is in the second trimester of pregnancy. C) Environmental factors determine the way in which 90 percent of our genes are expressed. D) Drugs and nutrition can alter normal gene expression.Drugs and nutrition can alter normal gene expression.Sex chromosomes of a normal male are ________. A) XX B) YY C) XY D) any of these, depending on the fatherXYA woman has blond hair and brown eyes. This statement is best described as indicating ________. A) allelic pairs B) recessive traits C) phenotype D) genotypephenotypeA chromosomal aberration in which part of a chromosome is lost is known as ________. A) deletion B) inversion C) translocation D) crossing-overdeletionInheritance of stature (height) in humans is probably due to ________. A) polyploidy B) polymorphism C) incomplete dominance D) polygene inheritancepolygene inheritanceAn individual who is heterozygous for a particular trait, yet expresses both alleles of that trait, is an example of ________. A) dominance B) recessive inheritance C) incomplete dominance D) sex-linked inheritanceincomplete dominanceGiven the information in Figure 29.1, what would be the genotype of the offspring designated by the blank square? A) GG B) Gg C) gg D) Dg ....... C .... g .....______________ C | CC| Cg | ....|______|______| g | Cg | ???| ....|______|______|ggGiven the information in Figure 29.1, what would the genotype ratio be for the offspring? A) 1:1:1:1 B) 1:2:1 C) 1:3 D) 4:0 ....... C .... g .....______________ C | CC| Cg | ....|______|______| g | Cg | ???| ....|______|______|1:2:1Given the information in Figure 29.1, what is the phenotype ratio (assuming C is dominant and there is no incomplete dominance)? A) 1:1:1:1 B) 1:2:1 C) 1:3 D) 4:0 ....... C .... g .....______________ C | CC| Cg | ....|______|______| g | Cg | ???| ....|______|______|1:3________ is the most common type of fetal testing. A) Blood chemistry B) Amniocentesis C) A DNA probe D) CVSAmniocentesisAmy's hand was exposed to X rays. A gene in a skin cell of her hand mutated. This mutant gene will ________. A) definitely cause skin cancer B) replicate itself and be passed on to Amy's children C) not form an exact duplicate of itself when the cell divides D) replicate itself when the cell divides but will not be passed on to Amy's offspringreplicate itself when the cell divides but will not be passed on to Amy's offspringThe main way a recessive allele would be expressed even when only one copy is present would be ________. A) dominance B) recessive inheritance C) sex-linked inheritance D) incomplete dominancesex-linked inheritanceGene mutations in human sex chromosomes tend to become visibly expressed ________. A) more frequently in males B) more frequently in females C) equally frequently in both sexes D) in neither males or femalesmore frequently in males