Deck 28: Embryology and Human Development

Question 1

Burrowing of the embryo into the endometrium is called

A)blastomere.
B)permeation.
C)implantation.
D)fertilization.
E)None of the answers are correct.

Answer 1

C

Question 2

Muscles, bones, and connective tissues form from

A)epiderm.
B)ectoderm.
C)epiblast.
D)endoderm.
E)mesoderm.

Answer 2

E

Question 3

Fusion of the pronuclei forming the zygote is known as

A)meiosis.
B)gamete formation.
C)penetration.
D)fertilization.
E)amphimixis.

Answer 3

E

Question 4

If a woman gives birth to identical triplets, how many ova were fertilized

A)one
B)two
C)three
D)one or two
E)from one to three

Question 5

The period of time after birth is called the ________ period.

A)embryonic
B)prenatal
C)postnatal
D)postconceptual
E)None of the answers are correct.

Question 6

During implantation, the developing blastocyst receives nutrients from (the)

A)placenta.
B)chorion.
C)endometrial glands.
D)cellular trophoblast.
E)None of the answers are correct.

Question 7

A hollow ball of cells is (the)

A)blastocyst.
B)gastrula.
C)morula.
D)embryo.
E)None of the answers are correct.

Question 8

If the mother is exposed to teratogens during pregnancy, what can happen to the fetus

A)These substances are immediately toxic to a fetus.
B)These substances can cross the placental barrier to cause damage to the fetus.
C)These substances dramatically reduce the blood supply that flows through the placenta and thus injure the fetus.
D)These substances interfere with the development of the extraembryonic membranes that support the fetus.
E)None of the answers are correct.

Question 9

Once cleavage starts, the zygote starts dividing, forming cells that are

A)morulas.
B)blastomeres.
C)blastocytes.
D)differentiated.
E)blastocysts.

Question 10

Among the important and complex events that occur during development are which of the following
(1)cleavage
(2)embryogenesis
(3)ovulation
(4)spermiogenesis
(5)placentation
(6)implantation

A)1, 2, 3, 4, 5, 6
B)1, 3, 5
C)2, 4, 6
D)1, 2, 5, 6
E)2, 3, 4

Question 11

The flagellum is used to

A)move the sperm to the oocyte.
B)penetrate the corona radiata.
C)become capacitated.
D)survive.
E)penetrate the oocyte.

Question 12

In the early blastocyst, the placenta will develop from (the)

A)blastocoele.
B)trophoblast.
C)inner cell mass.
D)morula.
E)None of the answers are correct.

Question 13

Sperm cannot perform fertilization until they

A)undergo activation.
B)undergo capacitation.
C)lose their acrosome.
D)are in the vagina for three days.
E)All of the answers are correct.

Question 14

During implantation, why doesn't the hyaluronidase erode the trophoblast as well as the endometrium

A)The trophoblast is coated in anti-hyaluronidase.
B)The trophoblast secretes an enzyme that breaks down the hyaluronidase.
C)The outer layer of the trophoblast is syncytial, with no cell junctions for the enzyme to attack.
D)The endometrium inactivates the enzyme before it can act on the trophoblast.
E)None of the answers are correct.

Question 15

The fluid-filled cavity separating the inner cell mass from the trophoblast is the

A)blastocoele.
B)amniotic cavity.
C)lacuna.
D)epiblast.
E)hypoblast.

Question 16

Because of the great loss of spermatozoa during the process of traveling from the vagina to the ampulla of the uterine tube where fertilization occurs, a male must have at least ________ spermatozoa per milliliter, or he will be functionally sterile.

A)10,000
B)100,000
C)2,000,000
D)20,000,000
E)500,000,000

Question 17

The process of cells specializing during development is

A)differentiation.
B)implantation.
C)meiosis.
D)embryology.
E)None of the answers are correct.

Question 18

After oocyte activation and completion of meiosis, the female chromosomes reorganize as the

A)syncytial trophoblast.
B)female pronucleus.
C)cellular trophoblast.
D)male pronucleus.
E)copulation.

Question 19

Fertilization is the process whereby

A)two haploid gametes fuse.
B)two polar bodies fuse to produce a zygote.
C)two diploid gametes join and recombine genetically.
D)the cells of a newly produced embryo divide.
E)None of the answers are correct.

Question 20

The length of the prenatal development period is called the ________ period.

A)gestation
B)embryology
C)spermatogenesis
D)atresia
E)None of the answers are correct.

Question 21

The ________ has mesoderm on the outside and endoderm on the inside.

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

Question 22

The fetus gains the greatest amount of weight during

A)the first three weeks of the second trimester.
B)the entire third trimester.
C)the entire second trimester.
D)Weight gain is evenly distributed throughout all of the stages of development.
E)None of the answers are correct.

Question 23

Anatomical features that appear or undergo significant change during the third trimester include

A)completion of pulmonary branching and alveolar formation.
B)formation of the plicae of the intestines.
C)completion of the formation of the nephrons.
D)the testes descending in male fetuses.
E)All of the answers are correct.

Question 24

The germ layer located on the dorsum of the embryo is the

A)mesoderm.
B)endoderm.
C)ectoderm.
D)hypoblast.
E)epiblast.

Question 25

Within the first twelve weeks of development, the basis for organ formation is established. This process is called

A)embryogenesis.
B)organogenesis.
C)implantation.
D)gastrulation.
E)None of the answers are correct.

Question 26

Problems with the formation of the chorion would affect

A)the embryo's ability to produce blood cells.
B)formation of the limbs.
C)the embryo's ability to derive nutrition from the mother.
D)lung formation.
E)None of the answers are correct.

Question 27

The first of the extraembryonic membranes to appear, which ultimately becomes involved in blood cell formation, is (the)

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

Question 28

The extraembryonic membrane that persists as part of the urinary bladder is (the)

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

Question 29

The relatively thin portion of the endometrium that covers the embryo and separates it from the uterine cavity is called the

A)decidua parietalis.
B)placenta.
C)decidua basalis.
D)villi.
E)decidua capsularis.

Question 30

At about nine days gestation, the inner cell mass is organized in two layers; of these layers, (the)________ faces the amnion.

A)hypoblast
B)endoderm
C)epiblast
D)mesoderm
E)None of the answers are correct.

Question 31

During the second trimester, the organ systems

A)will not change significantly in size, but will become functional.
B)of the placenta will grow much faster than the embryo itself.
C)will complete their functional development.
D)will not continue functional development, but will increase greatly in size.
E)None of the answers are correct.

Question 32

Developmental events that occur during the second trimester include

A)development of hair and sebaceous glands.
B)development of sweat glands.
C)keratin and nail production.
D)myelination of the spinal cord.
E)All of the answers are correct.

Question 33

The process of muscular activity that results in the forcible expulsion of the fetus from the uterus is called

A)development.
B)labor.
C)birth, or parturition.
D)placental expulsion.
E)None of the answers are correct.

Question 34

A fetus begins to look distinctly human

A)from the point of conception.
B)at the end of the first trimester.
C)by the beginning of the second trimester.
D)for the first time, at the end of the third trimester.
E)at 8 weeks when the embryo becomes the fetus.

Question 35

During the third trimester, which of the following occurs

A)All organ systems become functional.
B)The absolute weight gain is greatest.
C)The rate of growth slows.
D)All of the answers are correct.
E)None of the answers are correct.

Question 36

The mesoderm associated with the allantois spreads to cover the entire inside of the trophoblast. This combination of mesoderm and trophoblast is the

A)chorion.
B)allantois.
C)mesoderm.
D)blastodisc.
E)yolk sac.

Question 37

Formation of the germ layer is the process of

A)meiosis.
B)somite formation.
C)blastolation.
D)gastrulation.
E)None of the answers are correct.

Question 38

The chorion forms from the

A)inner cell mass.
B)placenta.
C)trophoblast.
D)ectoderm.
E)endoderm.

Question 39

A premature infant often is able to survive if born in the

A)first trimester.
B)third trimester.
C)second trimester.
D)few days prior to the expected due date.
E)None of the answers are correct.

Question 40

Which time period is the most dangerous in prenatal life

A)first trimester
B)second trimester
C)third trimester
D)labor
E)None of the answers are correct.

Question 41

Full term is

A)5 months.
B)9 months.
C)12 months.
D)18 months.
E)None of the answers are correct.

Question 42

Which of the following is the condition of the skull at birth

A)Only the chondrocranium exists.
B)The floor and roof of the cranium are incomplete.
C)The frontal bone has just begun forming.
D)The mandible is incomplete.
E)Only the roof of the skull remains incomplete.

Question 43

The collective term for embryonic and fetal development is ________.

Question 44

The first part of the nervous system to form is (the)

A)cerebrum.
B)neural tube.
C)spinal cord.
D)brain stem.
E)None of the answers are correct.

Question 45

Surgical cutting of the perineum during delivery is called

A)vasectomy.
B)tubal ligation.
C)episiotomy.
D)vagectomy.
E)None of the answers are correct.

Question 46

________ considers developmental events that occur in the first two months after fertilization.
(Note: Be sure to capitalize the first letter of your answer).

Question 47

The dilation stage of labor

A)occurs about an hour after the onset of true labor.
B)includes dilation of the cervix.
C)usually is short-a few minutes in length.
D)has contractions of the uterus spread only a few minutes apart.
E)All of the answers are correct.

Question 48

During the fertilization process, the joining of the male and female pronuclei is called ________.

Question 49

The first recognizable feature of the cardiovascular system is (the)

A)heartbeat at five months.
B)development of the aorta at two months.
C)formation of blood cells in the liver.
D)heartbeat at birth.
E)None of the answers are correct.

Question 50

When the sperm penetrates the egg plasmalemma, it causes an alteration in the chemical environment inside the oocyte and ________ follows.

Question 51

Which of the following is the result of the immature kidneys in the neonate

A)fast heart rate
B)high urinary water loss
C)poor thermoregulation
D)defecation mainly fetal debris
E)fetal blood vessels close

Question 52

If an ultrasound scan reveals that a fetus at six weeks of gestation is approximately the size of Lincoln on a penny,

A)the fetus is too small for its age.
B)the fetus is developing at a normal rate.
C)there is probably a problem with the placenta.
D)this fetus is probably only one of a multiple birth.
E)None of the answers are correct.

Question 53

The gradual modification of anatomical structures from conception to maturity is referred to as ________.

Question 54

Muscle are the result of maturing

A)myotomes.
B)sclerotomes.
C)notochord.
D)mesoderm.
E)apical ridges.

Question 55

If two sperm penetrate two different oocytes, the two resulting offspring would be fraternal ________.

Question 56

White matter of the spinal cord develops from the

A)notochord.
B)neuroepithelial layer.
C)mantle layer.
D)marginal layer.
E)neurocoel.

Question 57

The formation of sex-appropriate gonads begins around month

A)one.
B)two.
C)three.
D)four.
E)five.

Question 58

The last systems to complete prenatal development are (the)

A)renal and circulatory.
B)nervous and digestive.
C)renal and respiratory.
D)muscular and nervous.
E)None of the answers are correct.

Question 59

Which of the following forms the nucleus pulposus

A)mesoderm
B)somites
C)neural arch
D)notochord
E)sclerotomes

Question 60

The time period of the embryo is two weeks gestation to ________.

Question 61

The ________ is the site of early blood cell formation.

Question 62

The inner cavity of the blastocyst is called the ________.

Question 63

Blood flows to the placenta from the fetus through the ________ arteries.

Question 64

At about day nine of development of the blastocyst, the cells of the inner cell mass are organized into an oval sheet that is two layers thick, called the ________.

Question 65

Respiratory system changes that occur during the second trimester of development include the start of the formation of the alveoli and the ________.

Question 66

The mucous epithelium of the digestive tract forms from the ________.

Question 67

Each germ layer develops into specific structures. The nervous system develops from the ________.

Question 68

The first trimester is a critical period for development because events in the first 12 weeks establish the basis for organ formation, a process called ________.

Question 69

________ begins with the attachment of the blastocyst to the endometrium and continues as the blastocyst invades maternal tissues. (Note: Be sure to capitalize the first letter of your answer).

Question 70

The cells of the blastodisc that face the blastocoele are the ________.

Question 71

The cells of the blastocyst that become the embryo proper are the cells of the ________.

Question 72

The muscular system develops from the ________.

Question 73

The ________ begins with the onset of true labor, as the cervix dilates and the fetus begins to move down the cervical canal.

Question 74

________ development includes the changes from birth to maturity. (Note: Be sure to capitalize the first letter of your answer).

Question 75

For convenience, gestation is usually divided into three integrated ________.

Question 76

Collectively, the yolk sac, chorion, amnion, and allantois are called the ________ membranes.

Question 77

The ________ cells of the blastocyst are responsible for providing food to the developing embryo.

Question 78

The base of the ________ later gives rise to the bladder.

Question 79

Diffusion occurs between the maternal blood flowing through the ________ and fetal blood flowing through vessels within the chorionic villi.

Question 80

Surgical incision of the abdominal wall to remove the fetus is called a(n)________.