Deck 29: Development, Pregnancy, and Heredity

Question 1

The outer layer of the trophoblast that burrows into the lining of the uterus is the

A) embryoblast.
B) syncytiotrophoblast.
C) cytotrophoblast.
D) morula.
E) zona pellucida.

Answer 1

B

Question 2

After ovulation, the oocyte

A) waits passively for a sperm to penetrate.
B) releases negative ions that create an electrical gradient that all sperm swim toward.
C) releases chemotaxic signals to attract sperm to its location.
D) propels itself toward seminal fluid by calcium-dependent kinesis.

Answer 2

C

Question 3

The third through eighth weeks of development are known as the ________ period.

A) fetal
B) pre-embryonic
C) embryonic
D) cleavage

Answer 3

C

Question 4

The hormone that signals that fertilization and implantation have taken place is

A) pluripotent prolactin.
B) human chorionic gonadotropin.
C) gonadotropin releasing hormone.
D) progesterone.
E) pre-embryonic pellucida factor.

Question 5

The process by which a blastocyst embeds within the uterine endometrium is known as

A) cleavage.
B) morulation.
C) implantation.
D) capacitation.
E) the acrosome reaction.

Question 6

Cleavage occurs during

A) the fetal period.
B) the pre-embryonic period.
C) organogenesis.
D) the embryonic period.
E) fertilization.

Question 7

Implantation usually begins at about the end of the first ________ of development.

A) day
B) week
C) month
D) trimester

Question 8

Capacitation lasts several ________ and involves removal of ________.

A) seconds; lipids from the surface of the egg
B) hours; proteins from the surface of the sperm
C) days; carbohydrates from the surface of the egg
D) weeks; glycolipids from the surface of the sperm

Question 9

Sperm undergo a process of conditioning known as ________ after they arrive in the female reproductive tract.

Question 10

Cleavage involves a series of ________ divisions and ________ in the overall size of the conceptus.

A) meiotic; an increase
B) meiotic; no change
C) meiotic; a decrease
D) mitotic; no change
E) mitotic; an increase

Question 11

Which type of gamete remains viable for a longer time after it enters the female reproductive tract?

A) Sperm
B) Egg

Question 12

Cells within the embryoblast have the ability to differentiate into any type of cell within the body.

Question 13

What is the correct order of structures through which the sperm penetrates during fertilization?

A) Corona radiata, oocyte plasma membrane, zona pellucida
B) Zona pellucida, corona radiata, oocyte plasma membrane
C) Corona radiata, zona pellucida, oocyte plasma membrane
D) Zona pellucida, oocyte plasma membrane, corona radiata

Question 14

At the 16-cell stage, the conceptus is known as a(n)

A) trophoblast.
B) blastocyst.
C) embryoblast.
D) morula.
E) zygote.

Question 15

The trophoblast is located at the

A) periphery of the blastocyst.
B) center of the blastocyst.
C) periphery of the morula.
D) center of the morula.
E) center of the embryoblast.

Question 16

The maturation that occurs within the pre-embryonic and embryonic periods is known as ________.

Question 17

Polyspermy results in the production of monozygotic twins.

Question 18

The pre-embryonic period ends when

A) a morula is formed.
B) the zygote undergoes cleavage.
C) the blastocyst implants in the uterus.
D) the morula develops a trophoblast.

Question 19

During fertilization, the nuclei of the sperm and the ovum are referred to as ________, before they come together and fuse to form a single nucleus.

Question 20

Fertilization typically occurs in the ________, and it restores the ________ number of chromosomes.

A) ampulla of the uterine tube; haploid
B) ampulla of the uterine tube; diploid
C) body of the uterus; polyploid
D) isthmus of the uterine tube; haploid
E) isthmus of the uterine tube; polyploid

Question 21

Within the bilaminar germinal disc, the layer of columnar cells that is adjacent to the amniotic cavity is the ________ layer.

Question 22

Which structure is an important site for early blood cell formation and is the first of the extraembryonic membranes to form?

A) Amnion
B) Yolk sac
C) Chorion
D) Zona pellucida

Question 23

Approximately when in development does the bilaminar germinal disc begin to form?

A) Day 8
B) Day 32
C) Week 8
D) Week 24

Question 24

At the start of gastrulation, a long, thin depression known as the primitive ________ forms on the surface of the epiblast.

A) furrow
B) node
C) streak
D) groove
E) yolk

Question 25

Human chorionic gonadotropin stimulates the degeneration of the corpus luteum.

Question 26

The fingerlike structures of the placenta that form from its fetal portion are known as

A) amniotic villi.
B) chorionic villi.
C) amniotic stalks.
D) chorionic stalks.

Question 27

What thin membrane, continuous with the epiblast layer, secretes fluid to bathe the embryo?

A) Chorion
B) Amnion
C) Yolk sac
D) Corona radiata

Question 28

The maternal portion of the placenta arises from the

A) amnion.
B) ectoderm.
C) functional layer of the uterus.
D) germinal disc.
E) myometrium.

Question 29

The hypoblast layer of the blastodisc is made of

A) columnar cells and forms during the morula stage.
B) columnar cells and forms during gastrulation.
C) cuboidal cells and forms during the fetal period.
D) cuboidal cells and forms during the pre-embryonic period.

Question 30

Describe the main functions of the placenta.

Question 31

Human chorionic gonadotropin is secreted from cells of the

A) morula.
B) embryoblast.
C) syncytiotrophoblast.
D) zygote.

Question 32

The process by which the three primary germ layers are formed during the third week of development is known as ________.

Question 33

The outermost extraembryonic membrane that eventually helps form the placenta is the

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

Question 34

Gastrulation results in the formation of a(n)

A) morula.
B) embryo.
C) blastocyst.
D) trophoblast.
E) umbilical cord.

Question 35

When epiblast cells travel through the primitive streak and underneath the epiblast layer, that movement is described as

A) capacitation.
B) invagination.
C) chemotaxation.
D) cleavage.

Question 36

Blood cells and antibodies pass freely across the placenta.

Question 37

Presence of hCG in a woman's urine indicates that she is pregnant.

Question 38

Which pathogen (within the mother) is most likely to be transmitted across the placenta?

A) A multicellular parasite that is present during the first week of pregnancy
B) A multicellular parasite that is present during the sixth week of pregnancy
C) A blood-borne virus that is present during the first week of pregnancy
D) A blood-borne virus that is present during the sixth week of pregnancy

Question 39

Which structure develops directly into a bilaminar germinal disc?

A) Trophoblast
B) Embryoblast
C) Morula
D) Cytotrophoblast

Question 40

The germ layer between the ectoderm and the endoderm is the ________.

Question 41

The process of organogenesis begins in the fetal period.

Question 42

The primary germ layer that takes the place of the hypoblast is the

A) mesoderm.
B) endoderm.
C) centroderm.
D) chorion.
E) trophoblast.

Question 43

The process that involves the fusion of the two sides of the embryonic disc at a newly formed midline, thereby creating a cylindrical embryo is ________ folding.

A) invagination
B) cephalocaudal
C) transverse
D) amphiamniotic
E) coronal

Question 44

The structure of the mesoderm that induces formation of the neural tube is the

A) head mesenchyme.
B) amnion.
C) notochord.
D) paraxial mesoderm.

Question 45

The second trimester of a pregnancy includes months

A) 2-5
B) 4-6
C) 5-7
D) 5-9

Question 46

To prepare for the strain of labor and delivery, female reproductive hormones cause ligaments of pelvic joints to tighten.

Question 47

During pregnancy, estrogen and progesterone from the placenta

A) stimulate FSH and LH secretion and thereby stimulate ovarian follicle development.
B) inhibit FSH and LH secretion and thereby arrest ovarian follicle development.
C) stimulate GnRH secretion and thereby inhibit overgrowth of the uterus.
D) inhibit release of corticotropin-releasing hormone and thereby prevent excessive stress responses.

Question 48

What is the approximate duration of the fetal period of development?

A) 4 weeks
B) 12 weeks
C) 29 weeks
D) 39 weeks

Question 49

Drugs that lead to birth defects in the formation of the limbs are most damaging when the conceptus is exposed to them during weeks

A) 1-2 of development, before the placenta is fully formed.
B) 4-8 of development, when limbs are undergoing peak development.
C) 12-16 of development, when limbs have formed but are not fully mature.
D) 24-28 of development, when plasticity of surrounding tissues has been lost.

Question 50

Which part of the embryo develops into the kidneys?

A) Endoderm
B) Paraxial mesoderm
C) Notochord
D) Intermediate mesoderm

Question 51

Increases in weight of the conceptus are largest during the ________ two months of pregnancy.

A) first
B) middle
C) last

Question 52

Neurulation is the development of the nervous system from the

A) endoderm.
B) mesoderm.
C) ectoderm.
D) hypoderm.

Question 53

The future head and buttocks regions of the embryo are facilitated by the process of ________ folding.

A) cleavage
B) cephalocaudal
C) transverse
D) amitotic
E) chorionic

Question 54

Lateral plate mesoderm gives rise to most of the components of the cardiovascular system.

Question 55

Teratogens are most damaging to organ systems if exposure to them occurs

A) early in pre-embryonic development.
B) when the organ systems are undergoing peak development in the embryo.
C) in the fetal period, after systems have formed but have not completed maturation.

Question 56

Blocklike masses that form from paraxial mesoderm and develop into muscle, axial skeleton, cartilage, and dermis are known as ________.

Question 57

The trimester during which an embryo becomes a fetus is the ________ trimester.

A) first
B) second
C) third

Question 58

Substances that can cause birth defects or the death of the embryo are referred to as ________.

Question 59

In pregnant women, the high levels of estrogen and progesterone secretion seem to lead to

A) stronger nails and fuller hair.
B) weaker nails and thinner hair.

Question 60

Cephalocaudal folding occurs because of the rapid growth of the

A) amnion and embryonic disc.
B) yolk sac.

Question 61

Human placental lactogen ________ the effects of insulin and causes a pregnant woman's tissues to metabolize ________ glucose.

A) facilitates; more
B) facilitates; less
C) inhibits; more
D) inhibits; less

Question 62

One reason that pregnant women's metabolic rates change is that the placenta secretes

A) human chorionic gonadotropin, which stimulates metabolism of glucose and raises metabolic rate.
B) human chorionic thyrotropin, which stimulates the thyroid gland and raises metabolic rate.
C) human placental lactogen, which stimulates glycolysis and raises metabolic rate.
D) human chorionic somatomammotropin, which inhibits fatty acid metabolism and lowers metabolic rate.
E) prolactin, which lowers metabolic rate so that nutrients can be stored in milk.

Question 63

During pregnancy, the mother's

A) cardiac output and hematocrit rise.
B) cardiac output and hematocrit fall.
C) cardiac output rises and hematocrit falls.
D) cardiac output falls and hematocrit rises.

Question 64

Describe the causes and effects of gastrointestinal ailments during pregnancy.

Question 65

By the 4th month of pregnancy, the fundus of the uterus is located inches below the ________ and by the ninth month it is located at the level of the ________.

A) urinary bladder; umbilicus
B) umbilicus; xiphoid process
C) diaphragm; laryngeal prominence
D) pubic symphysis; heart

Question 66

Growth of the functional layer and prevention of menstruation during pregnancy are brought about by secretion of

A) relaxin.
B) progesterone.
C) cortisol.
D) human chorionic thyrotropin.
E) human placental lactogen.

Question 67

Changes in the size of the uterus during pregnancy are due to

A) hypertrophy but not hyperplasia.
B) hyperplasia but not hypertrophy.
C) both hypertrophy and hyperplasia.

Question 68

During pregnancy, a woman's areolae and nipples become darker under the influence of

A) melanin from the pineal gland.
B) vasopressin from the posterior pituitary gland.
C) melanocyte-stimulating hormone from the placenta.
D) estrogen and progesterone from the ovary.

Question 69

Blood vessel growth within the uterus is promoted by the hormone ________.

Question 70

Increased levels of estrogen, progesterone, and corticosteroids result in increased insulin resistance during pregnancy.

Question 71

The uterine enlargement that occurs during the first 10 weeks of pregnancy is mostly the result of

A) growth of the conceptus from a zygote to a fetus.
B) amniotic fluid production as well as growth of uterine muscle and the placenta.

Question 72

Although pregnancy sometimes results in frequent urination, the one trimester when this tends to be not as problematic is the

A) first.
B) second.
C) third.

Question 73

Which type of food do women suffering from morning sickness generally prefer?

A) Carbohydrate-rich foods
B) Protein-rich foods

Question 74

Edema and varicose veins in the lower extremities sometimes develop in the third trimester of a pregnancy due to

A) decreased cardiac output.
B) elevated blood pressure.
C) compression of abdominal blood vessels.
D) elevated hematocrit.

Question 75

Although pregnancies are highly variable, morning sickness is most commonly experienced in the ________ trimester.

A) first
B) second
C) third

Question 76

Difficulty with breathing that may accompany physical exertions of a pregnant woman is called ________.

Question 77

Hormonal and neural changes during pregnancy function to facilitate diffusion of gases across the placenta. One way this occurs is by ________ respiration rate, thereby ________ CO₂ levels in the blood.

A) increasing; raising
B) increasing; lowering
C) decreasing; raising
D) decreasing; lowering

Question 78

During pregnancy, the levels of CRH and aldosterone within a mother's blood decline.

Question 79

Prolactin is secreted from the ________ gland, and its levels ________ during pregnancy.

A) hypothalamus; double
B) mammary; double
C) corpus luteum; increase tenfold
D) anterior pituitary; increase tenfold

Question 80

When pregnant, a woman has an increased sensitivity to the hormone angiotensin.