Chapter 4: Prenatal Development

Question 1

development that occurs between the moment of conception and the beginning of the birth process

Answer 1

prenatal development

Question 2

first phase of prenatal development, lasting from conception until the developing organism becomes firmly attached to the wall of the uterus

Answer 2

period of the zygote (germinal period)

Question 3

second phase of the prenatal development, lasting from the third through the eighth prenatal week, during which the major organs and anatomical structures take shape

Answer 3

period of the embryo

Question 4

third phase of prenatal development, lasting from the ninth prenatal week until birth; during this period, all major organ systems begin to function and the fetus grows rapidly

Answer 4

period of the fetus

Question 5

name given to the ball of cells formed when the fertilized egg first begins to divide

Answer 5

blastocyst

Question 6

name given to the prenatal organism from the third through the eighth week after conception

Answer 6

embryo

Question 7

the burrowing of the blastocyst into the lining of the uterus

Answer 7

implantation

Question 8

a watertight membrane that surrounds the developing embryo, serving to regulate its temperature and to cushion it against injuries

Answer 8

amnion

Question 9

a membrane that, as the amnion, becomes attached to the uterine tissues to gather nourishment for the embryo

Answer 9

chorion

Question 10

an organ, formed from the lining of the uterus and the chorion, that provides for respiration and nourishment of the unborn child and the elimination of its metabolic wastes

Answer 10

placenta

Question 11

the primitive spinal cord that develops from the ectoderm and becomes the central nervous system

Answer 11

neural tube

Question 12

name given to the prenatal organism from the ninth week of pregnancy until birth

Answer 12

fetus

Question 13

white, cheesy substance that covers the fetus to protect the skin from chapping

Answer 13

vernix

Question 14

fine hair covering the fetus’s body that helps vernix stick to the skin

Answer 14

lanugo

Question 15

a point between the 22nd and 28th prenatal weeks when survival outside the uterus is possible

Answer 15

age of viability

Question 16

external agents, such as viruses, drugs, chemicals, and radiation, that can harm a developing embryo or fetus

Answer 16

teratogens

Question 17

a period during which an organism is most susceptible to certain environmental influences; outside this period, the same environmental influences must be much stronger to produce comparable effects

Answer 17

sensitive period

Question 18

a disease that has little effect on a mother but may cause a number of serious birth defects in unborn children who are exposed in the first three to four months of pregnancy

Answer 18

rubella (german measles)

Question 19

disease caused by a parasite found in raw meat and cat feces; can cause birth defects if transmitted to an embryo in the first trimester and miscarriage later in pregnancy

Answer 19

toxoplasmosis

Question 20

a common sexually transmitted disease/infection that may cross the placental barrier in the middle and later stages of pregnancy, causing miscarriage or serious birth defects

Answer 20

syphilis

Question 21

a sexually transmitted disease/infection that can infect infants at birth, causing blindness, brain damage, or even death, if not diagnosed and treated

Answer 21

genital herpes

Question 22

a viral disease that can be transmitted from a mother to her fetus or newborn and that results in a weakening of the body’s immune system and, ultimately, death

Answer 22

Acquired immune deficiency syndrome (AIDS

Question 23

a mild tranquilizer that, taken early in pregnancy, can produce a variety of malformations of the limbs, eyes, ears, and heart of the baby

Answer 23

thalidomide

Question 24

a synthetic hormone, formerly prescribed to prevent miscarriage, that can produce cervical cancer in adolescent female offspring and genital tract abnormalities in males

Answer 24

Diethylstilbestrol (DES)

Question 25

term used to describe the full range of congenital problems commonly observed in the offspring of mothers who consumed alcohol during pregnancy

Answer 25

Fetal alcohol spectrum disorder (FASD)

Question 26

a congenital disorder in which the upper lip has a vertical (or pair of vertical) opening or groove

Answer 26

cleft lip

Question 27

a congenital disorder in which the roof of the mouth does not close properly during embryonic development, wrestling in an opening or groove in the roof of the mouth

Answer 27

cleft palate

Question 28

B-complex vitamin that helps to prevent defects of the central nervous system

Answer 28

folate

Question 29

synthetic version of folate

Answer 29

folic acid

Question 31

a bulging of the spinal cord through a gap in the spinal column

Answer 31

spina bifida

Question 32

a birth defect in which the brain and neural tube fail to develop or develop in completely and the skull does not close

Answer 32

anencephaly

Question 33

a newborn infant from birth to approximately 1 month old

Answer 33

neonate

Question 34

Which of the following events marks the transition between when we label the developing organism a zygote to when we begin to label it an embryo?
a. conception
b. ovulation
c. implantation
d. cell division

Answer 34

c. implantation

Question 35

Which organ is responsible for the transmission of nutrients and wastes between the developing organism and the pregnant woman?
a. amnion
b. placenta
c. chorion
d. embryonic disk

Answer 35

b. placenta

Question 36

What is the most critical period in prenatal development for potential damage to the developing organism from teratogens?
a. the period of the embryo
b. the period of the zygote
c. the period of the fetus
d. the period of the blastocyst

Answer 36

a. the period of the embryo

Question 37

When a pregnant woman drinks alcohol during her pregnancy, she risks having a child born with ________________

Answer 37

fetal alcohol spectrum disorder (FASD)

Question 38

Teratogens are external factors such as _______________, ___________________,or chemicals that harm the developing organism.

Answer 38

drugs; disease

Question 39

Sexual differentiation begins when a gene on the _____ chromosome instructs the ____________ to produce testes if the developing organism is a male.

Answer 39

Y; indifferent gonad

Question 40

Erica was born in 1960 and she appeared at birth to be a normal, healthy girl. Her life proceeded normally until she turned 20. Then she discovered that she had a rare
form of reproductive organ cancer and that she would be unlikely to be able to have children herself. Her doctor wondered whether her mother had taken ___________ during her pregnancy with Erica. He suspected that the drug could have been a teratogen that caused Erica’s reproductive abnormalities.

Answer 40

Diethylstilbestrol (DES)