Chapter 28

1) What destroys the zona pellucida sperm-binding receptors?
A) the acrosomal reaction
B) zonal inhibiting proteins
C) the process of capacitation
D) human placental lactogen

B

The result of polyspermy in humans is ________.
A) multiple births
B) a nonfunctional zygote
C) interruption of meiosis
D) mitotic insufficiency

B

It 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 days

C

Milk ejection (the letdown reflex) is stimulated by which of the following hormones associated with pregnancy?
A) inhibin
B) oxytocin
C) prolactin
D) gonadotropin

B

The corpus luteum prevents loss of the implanted embryo through menstruation by secreting ________.
A) human chorionic gonadotropin
B) luteinizing hormone
C) estrogens and progesterone
D) follicle-stimulating hormone

C

The placenta, a vitally important metabolic organ, is made up of a contribution from mother and fetus. Which portion is from the fetus?
A) chorion
B) umbilicus
C) yolk sac
D) amnion

A

Relaxin 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
C) relax the pubic symphysis
D) prevent morning sickness

C

Proteases and acrosin are enzymes. How do they function in reproduction?
A) They neutralize the mucous secretions of the uterine mucosa.
B) They direct the sperm to the egg through chemical messengers.
C) They act to break down the protective barriers aro

C

Which of the following is NOT a primary germ layer?
A) ectoderm
B) mesoderm
C) epiderm
D) endoderm

C

The formation of endodermal and ectodermal germ layers occurs at ________.
A) fertilization
B) cleavage
C) gastrulation
D) blastula formation

C

Which hormone maintains the viability of the corpus luteum?
A) estrogen
B) progesterone
C) human chorionic gonadotropin
D) human placental lactogen

C

Which of the following events does NOT occur during the first 8 weeks of development?
A) beginning of ossification
B) formation of a functional cardiovascular system
C) presence of all body systems
D) myelination of the spinal cord

D

Which of the following is NOT a correct matching of a fetal structure with what it becomes at birth?
A) foramen ovale�fossa ovalis
B) ductus arteriosus�ligamentum teres
C) ductus venosus�ligamentum venosum
D) umbilical arteries�medial umbilical ligaments

B

Which body system of a pregnant woman undergoes the most dramatic physiological
changes during pregnancy?
A) digestive system
B) urinary system
C) cardiovascular system
D) respiratory system

C

The correct sequence of preembryonic structures is ________.
A) zygote, blastocyst, morula
B) zygote, morula, blastocyst
C) blastocyst, morula, zygote
D) morula, zygote, blastocyst

B

Prior to the let-down reflex, the mammary glands secrete a yellowish fluid called ________ that has less lactose than milk and almost no fat.
A) meconium
B) colostrum
C) bilirubin
D) prolactin

B

How long is the secondary oocyte viable and capable of being fertilized after it is ovulated?
A) 12-24 hours
B) 24-36 hours
C) 36-72 hours
D) a full week

A

Select 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 the vagina's acidic environment.
C) If e

B

Shortly after implantation ________.
A) maternal blood sinuses bathe the inner cell mass
B) myometrial cells cover and seal off the blastocyst
C) the trophoblast forms two distinct layers
D) the embryo gastrulates (within 3 days)

C

Gastrulation begins when a groove with raised edges called the ________ appears on the dorsal surface of the embryonic disc.
A) placenta
B) spinal cord
C) primitive streak
D) notochord

C

Muscle tissue is formed by the ________.
A) mesoderm
B) ectoderm
C) endoderm
D) epiderm

A

Neural tissue is formed by the ________.
A) epiderm
B) endoderm
C) mesoderm
D) ectoderm

D

The trophoblast is mostly responsible for forming the ________.
A) allantois
B) archenteron
C) placental tissue
D) lining of the endometrium

C

The cardiovascular system of a newborn must be adjusted after the infant takes its first breath. Which of the following is also true?
A) The foramen ovale between the atria of the fetal heart closes at the moment of birth.
B) The ductus venosus is disconn

D

Sperm move to the uterine tube through uterine contractions and the energy of their own flagella. What other factor is involved in sperm movement?
A) hormonal attraction to the ova
B) reverse peristalsis of the uterus and uterine tubes
C) the cilia on the

B

At which stage of labor is the "afterbirth" expelled?
A) dystocia
B) expulsion
C) placental
D) full dilation

C

Which hormone is NOT produced by the placenta?
A) human placental lactogen
B) human chorionic gonadotropin
C) relaxin
D) oxytocin

D

During which stage of labor is the fetus delivered?
A) dilation stage
B) expulsion stage
C) placental stage
D) gastrula stage

B

Implantation of the blastocyst is the result of all of the following EXCEPT ________.
A) phagocytosis by the trophoblast cells
B) digestive enzymes and growth factors produced by the trophoblast cells
C) settling of the blastocyst onto the prepared uterin

A

Cleavage as part of embryonic development is distinctive because it involves ________.
A) cell division by mitosis with little or no growth between successive divisions
B) forming the primary germ layers
C) splitting the cell into two separate cells
D) me

A

Which of the following is true in reference to what may pass through the placental barriers?
A) nutrients and respiratory gases only
B) hormones, blood cells, and nutrients
C) nutrients, respiratory gases, wastes, and alcohol
D) respiratory gases, hormone

C

Derivatives of the mesoderm include ________.
A) all nervous tissue
B) vertebrae and ribs
C) glandular derivatives of the digestive tract
D) epithelium of the digestive tract

B

Derivatives of the endoderm include ________.
A) epithelial lining of the respiratory tract
B) kidneys and gonads
C) heart and blood vessels
D) brain and spinal cord

A

Which of the choices below occurs if implantation is successful?
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 begin

A

Select the correct statement about the special fetal blood vessels.
A) The distal parts of the umbilical arteries form the superior vesical arteries.
B) The fossa ovalis becomes the foramen ovale.
C) The umbilical vein becomes the ligamentum teres.
D) The

C

At what point is meiosis II completed for the female gamete?
A) puberty
B) ovulation
C) fertilization
D) implantation

C

A urine test reveals a positive result for human chorionic gonadotropin (hCG). This indicates ________ was successful.
A) ovulation
B) fertilization
C) implantation
D) gastrulation

C

The first major event in organogenesis is ________.
A) neurulation
B) ossification
C) myelination
D) gastrulation

A

As pregnancy continues, the increasing bulkiness of the anterior abdomen changes the woman's center of gravity, possibly causing an accentuated lumbar curvature called ________.
A) kyphosis
B) scoliosis
C) lordosis
D) hunchback

C

As the infant's head is forced against the cervix with each contraction, the cervix effaces, which means that it ________.
A) crowns
B) softens
C) dilates
D) thins

D

In the block to polyspermy, entry of the sperm's contents causes ________ levels in the oocyte's cytoplasm to rise, triggering the cortical reaction.
A) sodium ion
B) calcium ion
C) phosphate ion
D) ATP

B

Neural tissue develops from the ________.
A) endoderm
B) entoderm
C) ectoderm
D) mesoderm

C

Cells of the ________ gather around the notochord and neural tube and produce the vertebra and rib at their associated level.
A) dermatome
B) myotome
C) intermediate mesoderm
D) sclerotome

D