Deck 27: Development and Inheritance

Question 1

After 3 days,a pre-embryo becomes a solid ball of cells known as a

A)chorion.
B)blastomere.
C)lacuna.
D)morula.
E)blastocyst.

Answer 1

D

Question 2

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

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

Answer 2

C

Question 3

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 lacunae.
D)form a capillary network in the trophoblast.
E)increase in size and penetrate the blastocyst.

Answer 3

C

Question 4

________ is the time spent in growing within the uterus.

A)Gastrulation
B)Gestation
C)Development
D)Pregnancy
E)Embryonization

Question 5

Contact of a sperm with the oocyte membrane does not cause

A)oocyte activation.
B)completion of the second meiosis.
C)formation of the second polar body.
D)membrane fusion.
E)a decrease in calcium released from the oocyte.

Question 6

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 7

The individual cells produced by cleavage are called

A)embryos.
B)blastomeres.
C)blastocytes.
D)blastocysts.
E)zygotes.

Question 8

During amphimixis,

A)sperm become capacitated.
B)the zygote is formed with 46 chromosomes.
C)the male and female pronuclei fuse.
D)meiosis occurs.
E)gametes are formed.

Question 9

Completion of cytokinesis does not lead to

A)production of two blastomeres.
B)division of the cytoplasm into two portions.
C)initiation of interphase.
D)completion of cleavage.
E)formation of a polar body.

Question 10

A blastocyst is a(n)

A)extra-embryonic membrane.
B)solid ball of cells.
C)hollow ball of cells.
D)portion of the placenta.
E)origin of the urinary bladder.

Question 11

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 12

The almost identical cells produced by cleavage divisions are called

A)morulas.
B)blastomeres.
C)trophoblasts.
D)blastocoeles.
E)ova.

Question 13

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 14

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 15

Figure 27-1
Identify the structures labeled "4."

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

Question 16

Attachment to and penetration of the endometrium by the blastocyst is referred to as

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

Question 17

Which of the following is not part of fertilization?

A)release of acrosomal enzymes
B)oocyte activation
C)completion of meiosis II
D)amphimixis
E)completion of meiosis I

Question 18

Each of the following statements concerning development is true except

A)embryonic development includes the events that occur in the first 2 months.
B)fetal development occurs from the 9th week until birth.
C)the first trimester is when the fetus first looks distinctively human.
D)postnatal development begins at birth.
E)organ development is complete by the end of the 6th month.

Question 19

Fertilization is complete when which of the follow occurs?

A)oocyte activation
B)pronucleus formation
C)spindle formation
D)amphimixis and cleavage
E)formation of blastomeres

Question 20

During implantation,the

A)syncytial 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 21

By day 12 of embryonic development,mesoderm begins to form through

A)embryogenesis.
B)gastrulation.
C)mitosis.
D)meiosis.
E)None of the answers is correct.

Question 22

The oval,three-layered sheet produced by gastrulation is called the

A)embryo.
B)ectoderm.
C)inner cell mass.
D)embryonic disc.
E)yolk sac.

Question 23

The extra-embryonic membrane that forms blood cells is the

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

Question 24

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 25

Identify what process is occurring at the structure labeled "6."

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

Question 26

The endoderm forms

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

Question 27

Endoderm + mesoderm = which extra-embryonic membrane(s)?

A)chorion
B)amnion
C)allantois
D)yolk sac
E)both yolk sac and allantois

Question 28

Figure 27-1
Identify the stage labeled "12."

A)zygote
B)morula
C)blastocyst
D)trophoblast
E)cytotrophoblast

Question 29

The mesoderm and the cytotrophoblast combine to form the

A)amnion.
B)amniotic sac.
C)chorion.
D)allantois.
E)None of the answers is correct.

Question 30

All of the following are true of the allantois except

A)it derives partly from endoderm.
B)it projects into the umbilical stalk.
C)it derives partly from mesoderm.
D)part will develop as the urinary bladder.
E)it acts as the fetal bone marrow.

Question 31

The trophoblast has many of the characteristics of ________ cells.

A)cardiac
B)cancer
C)infectious
D)smooth muscle
E)None of the answers is correct.

Question 32

The extra-embryonic membrane that forms a fluid-filled sac is the

A)yolk sac.
B)amnion.
C)allantois.
D)All of the answers are correct.
E)None of the answers is correct.

Question 33

Which of the following descriptors regarding the trophoblast is false?

A)spreads into the endometrium
B)absorbs nutrients released by degenerating endometrial glands
C)has both a syncytial and cellular component
D)is derived from the inner cell mass
E)causes maternal blood vessels to break down

Question 34

The ectoderm forms

A)muscle.
B)blood.
C)neural tissues.
D)the lining of the stomach and small intestine.
E)the urinary system.

Question 35

Figure 27-1
Identify the stage labeled "8."

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

Question 36

The mesoderm forms

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

Question 37

During gastrulation,

A)the blastomeres fuse.
B)the placenta penetrates the endometrium.
C)three germ layers are formed.
D)blastomeres form.
E)the neural tube closes.

Question 38

The extra-embryonic membrane that forms the fetal portion of the placenta is the

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

Question 39

Figure 27-1

-What is the developmental fate of "9?"

A)forms the embryo
B)forms the trophoblast
C)forms the chorion
D)forms the placenta
E)dissolves completely

Question 40

Which of the following is not one of the extra-embryonic membranes?

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

Question 41

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

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

Question 42

Deoxygenated blood is carried to the placenta by the

A)umbilical vein.
B)umbilical arteries.

Question 43

The embryonic heart starts beating as blood begins to flow through chorionic vessels at approximately ________ of development.

A)day 3
B)day 12
C)week 2
D)week 3
E)the second trimester

Question 44

The hormone that increases the flexibility of the pubic symphysis during pregnancy is

A)oxytocin.
B)progesterone.
C)human chorionic gonadotropin.
D)human placental lactogen.
E)relaxin.

Question 45

The placenta is not a source of which of the following hormones?

A)hCG
B)relaxin
C)placental lactogen
D)progesterone
E)prolactin

Question 46

Which of the following does not occur during the first trimester?

A)cleavage
B)implantation
C)separation of blastomeres to form monozygotic twins
D)gastrulation
E)organs become functional

Question 47

By the end of gestation,which of the following has not occurred?

A)Maternal blood volume has increased 50%.
B)Maternal nutritional requirements has increased 30%.
C)The uterus has increased in size by 10 fold.
D)The kidney's GFR has increased 2 fold.
E)The bladder size has been reduced.

Question 48

The period of gestation that is characterized by the largest fetal weight gain and fat deposition is the ________ trimester.

A)first
B)second
C)third

Question 49

The first stage of labor is the ________ stage.

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

Question 50

Figure 27-2
Identify the structure labeled "3."

A)umbilical cord
B)placenta
C)myometrium
D)amniotic cavity
E)yolk sac

Question 51

Figure 27-2
Identify the structure labeled "4."

A)amnion
B)chorion
C)myometrium
D)placenta
E)endometrium

Question 52

Figure 27-2
Identify the structure labeled "5."

A)amniotic cavity
B)chorion
C)amnion
D)placenta
E)endometrium

Question 53

Figure 27-2
Identify the structure labeled "6."

A)umbilical cord
B)placenta
C)chorion
D)amnion
E)myometrium

Question 54

Embryonic and early fetal development occurs in the ________ trimester.

A)first
B)second
C)third

Question 55

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

A)first
B)second
C)third

Question 56

The ________ is formed by a portion of the allantois,blood vessels,and remnants of the yolk sac.

A)amnion
B)body stalk
C)chorion
D)umbilical cord
E)placenta

Question 57

All of the following occur during pregnancy except

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 58

Oxygenated blood is carried away from the placenta by the

A)umbilical vein.
B)umbilical arteries.

Question 59

In pregnancy,expansion of the uterus results from

A)increased production of additional smooth muscle cells.
B)hypertrophy of smooth muscle cells.

Question 60

Figure 27-2
Identify the structure labeled "7."

A)amnion
B)chorion
C)myometrium
D)placenta
E)endometrium

Question 61

Progesterone calms the myometrium and prevents contraction.What factor does not 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)relaxation of the cervix

Question 62

The infancy stage of life is considered to be over when the baby reaches ________ of age.

A)1 year
B)2 years
C)6 months
D)1 month
E)18 months

Question 63

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

Question 64

A person's original chromosomes and their component genes constitute that person's

A)autosomal inheritance.
B)genotype.
C)phenotype.
D)allele.
E)locus.

Question 65

Which hormone stimulates the milk let-down reflex?

A)progesterone
B)oxytocin
C)estrogen
D)relaxin
E)GnRH

Question 66

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)autosomal
E)polygenic

Question 67

The traits of an individual controlled by his or her genotype are his or her

A)epigenome.
B)genotypical inheritances.
C)alleles.
D)phenotype.
E)karyotype.

Question 68

The clinical term for "growing old" is

A)maturation.
B)aging.
C)senescence.
D)apoptosis.
E)senility.

Question 69

The placenta is expelled from the uterus during the ________ stage of labor.

A)placental
B)expulsion
C)dilation
D)contraction
E)afterbirth

Question 70

The various forms of any one gene are called

A)homologous.
B)homozygous.
C)heterozygous.
D)autosomes.
E)alleles.

Question 71

Which of the following does not describe non-sex chromosomes?

A)diploid
B)haploid
C)produced by mitosis
D)genetically identical
E)called somatic cells

Question 72

All of the following occur at puberty except

A)FSH levels rise.
B)GnRH levels decline.
C)levels of sex hormones rise.
D)skeletal muscle fibers are stimulated.
E)secondary sexual characteristics begin to develop.

Question 73

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

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

Question 74

Which of the following is a puberty-related change caused by increased testosterone levels?

A)accelerated bone deposition and skeletal growth
B)loss of terminal hairs on the face and chest
C)replication of skeletal muscle fibers
D)thinning of the vocal folds
E)decreased erythropoiesis

Question 75

The developmental period heralded by the onset of puberty is known as

A)the neonatal stage.
B)infancy.
C)childhood.
D)adolescence.
E)maturity.

Question 76

How many chromosomes do human somatic cells contain?

A)22
B)23
C)44
D)46
E)92

Question 77

Which of the following hormones is the cause of most puberty-related changes in a female?

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

Question 78

If an individual carries two different alleles for the same trait,the individual is ________ for the trait.

A)homologous
B)homozygous
C)heterozygous
D)autosomal
E)polygenic

Question 79

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)constrict the cervix.
E)None of the answers is correct.

Question 80

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.