Deck 29: Development and Inheritance

Question 1

The penetration of the endometrium by the blastocyst is referred to as

A)cleavage.
B)implantation.
C)placentation.
D)embryogenesis.
E)fertilization.

Answer 1

B

Question 2

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.

Answer 2

C

Question 3

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

Answer 3

B

Question 4

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.

Question 5

The period of gestation when the rudiments of all major organ systems are established is the ________ trimester.

A)first
B)second
C)third

Question 6

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.

Question 7

The period of gestation that is characterized by rapid fetal growth and fat deposition is the ________ trimester.

A)first
B)second
C)third

Question 8

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.

Question 9

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.

Question 10

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

Question 11

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.

Question 12

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.

Question 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.

Question 14

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.

Question 15

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.

Question 16

________ are nearly identical cells that are produced by early cleavages.

A)Blastomeres
B)Morulas
C)Gastrulas
D)Amnions
E)Blastulas

Question 17

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.

Question 18

Polyspermy results in

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

Question 19

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.

Question 20

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.

Question 21

The trophoblast has many of the characteristics of ________ cells.

A)cardiac
B)cancer
C)infectious
D)rejuvenating
E)epithelial

Question 22

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.

Question 23

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.

Question 24

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.

Question 25

The endoderm forms

A)muscle.
B)blood.
C)neural tissue.
D)skin.
E)the urinary bladder.

Question 26

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.

Question 27

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.

Question 28

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.

Question 29

The mesoderm and the trophoblast combine to form the

A)amnion.
B)amniotic sac.
C)chorion.
D)allantois.
E)inner cell mass.

Question 30

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.

Question 31

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.

Question 32

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

Question 33

A space opens within the inner cell mass that will form the

A)blastocoele.
B)lacunae.
C)amniotic cavity.
D)chorion.
E)allantois.

Question 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.

Question 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.

Question 36

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.

Question 37

The mesoderm forms

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

Question 38

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.

Question 39

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.

Question 40

The ectoderm forms

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

Question 41

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

Question 42

The extraembryonic membrane that forms the fetal portion of the placenta is the

A)yolk sac.
B)amnion.
C)allantois.
D)chorion.
E)decidua.

Question 43

Figure 29-1 Early Human Development
Use Figure 29-1 to answer the following questions:
Identify the stage labeled "12."

A)zygote
B)early morula
C)blastocyst
D)trophoblast
E)late morula

Question 44

Which embryonic germ layer forms the linings of the respiratory and digestive tracts?

A)mesoderm
B)ectoderm
C)trophoderm
D)endoderm
E)epiderm

Question 45

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.

Question 46

The extraembryonic membrane that forms blood is the

A)yolk sac.
B)amnion.
C)allantois.
D)chorion.
E)decidua.

Question 47

Figure 29-1 Early Human Development
Use Figure 29-1 to answer the following questions:
Identify the stage labeled "8."

A)zygote
B)early morula
C)blastomere
D)trophoblast
E)advanced morula

Question 48

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.

Question 49

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.

Question 50

Which embryonic germ layer forms the brain and spinal cord?

A)ectoderm
B)endoderm
C)trophoderm
D)epiderm
E)mesooderm

Question 51

In ________,implantation occurs somewhere other than in the uterus.

A)ectopic pregnancy
B)hydramnios
C)placenta previa
D)abortion
E)spontaneous abortion

Question 52

The extraembryonic membrane that forms a fluid-filled sac is the

A)yolk sac.
B)amnion.
C)allantois.
D)chorion.
E)decidua.

Question 53

The extraembryonic membrane that gives rise to the umbilical cord is the

A)yolk sac.
B)allantois.
C)amnion.
D)chorion.
E)decidua.

Question 54

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.

Question 55

Which embryonic germ layer forms connective tissues such as bone and cartilage?

A)epiderm
B)trophoderm
C)ectoderm
D)mesooderm
E)endoderm

Question 56

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.

Question 57

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.

Question 58

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

Question 59

Figure 29-1 Early Human Development
Use Figure 29-1 to answer the following questions:
Identify the structures labeled "4."

A)zygotic twins
B)morula
C)blastomere
D)trophoblast
E)polar bodies

Question 60

Which of the following is not one of the extraembryonic membranes?

A)yolk sac
B)amnion
C)allantois
D)chorion
E)umbilical cord

Question 61

By the end of gestation,maternal blood volume normally increases by almost ________ percent.

A)20
B)25
C)50
D)80
E)100

Question 62

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.

Question 63

The first stage of labor is the ________ stage.

A)dilation
B)expulsion
C)placental
D)decidual
E)neonate

Question 64

Figure 29-2 Fetus at 10 Weeks
Use Figure 29-2 to answer the following questions:
Identify the structure labeled "2."

A)decidua basalis
B)chorion
C)amnion
D)placenta
E)endometrium

Question 65

During gestation,contraction of the myometrium is inhibited by ________,produced by the corpus luteum.

A)progesterone
B)estrogen
C)oxytocin
D)prostaglandins
E)inhibin

Question 66

Figure 29-2 Fetus at 10 Weeks
Use Figure 29-2 to answer the following questions:
Identify the structure labeled "7."

A)amnion
B)chorion
C)decidua basalis
D)placenta
E)endometrium

Question 67

Stretching of the cervix causes an increase in the blood levels of

A)estrogen.
B)progesterone.
C)oxytocin.
D)relaxin.
E)chorionic gonadotropin.

Question 68

Figure 29-2 Fetus at 10 Weeks
Use Figure 29-2 to answer the following questions:
Identify the structure labeled "6."

A)umbilical cord
B)placenta
C)decidua basalis
D)amnion
E)decidua parietalis

Question 69

Figure 29-1 Early Human Development
Use Figure 29-1 to answer the following questions:
What is the developmental fate of "9"?

A)forms the embryo
B)forms the trophoblast
C)forms the chorion
D)forms the placenta
E)forms the decidua parietalis

Question 70

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.

Question 71

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.

Question 72

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.

Question 73

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.

Question 74

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.

Question 75

Figure 29-2 Fetus at 10 Weeks
Use Figure 29-2 to answer the following questions:
Identify the structure labeled "4."

A)amnion
B)chorion
C)decidua basalis
D)placenta
E)endometrium

Question 76

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.

Question 77

Figure 29-2 Fetus at 10 Weeks
Use Figure 29-2 to answer the following questions:
Identify the structure labeled "5."

A)umbilical cord
B)amniotic cavity
C)decidua basalis
D)decidua capsularis
E)yolk sac

Question 78

Figure 29-2 Fetus at 10 Weeks
Use Figure 29-2 to answer the following questions:
Identify the structure labeled "3."

A)umbilical cord
B)placenta
C)decidua basalis
D)decidua capsularis
E)yolk sac

Question 79

Figure 29-1 Early Human Development
Use Figure 29-1 to answer the following questions:
Identify the process occurring at the structure labeled "13."

A)fertilization
B)ovulation
C)implantation
D)migration
E)gastrulation

Question 80

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