21) All of the following can pass through a healthy : 1403074
21) All of the following can pass through a healthy placenta EXCEPT which one?
D) some antibodies
E) blood cells
22) Which one of the following embryonic features is the forerunner of the brain and spinal cord?
A) pharyngeal arches
C) yolk sac
D) neural groove
E) chorionic villi
23) The figure above shows the development of the human embryo during days 19-24. Which of the following organs forms from the ectodermal folds of the embryo?
A) stomach and small intestine
B) kidneys, ureters, and bladder
E) brain and spinal cord
24) Which one of the following statements about gender determination is TRUE?
A) The male gender is determined by the presence of only one X chromosome.
B) The male gender is determined by the presence of a Y chromosome.
C) The hormones estrogen and progesterone are key players in the development of internal and external female genitalia.
D) The development of male genitalia is the "default" condition in the absence of estrogen.
E) The development of female genitalia is activated by the presence of anti-Mullerian hormone.
25) The muscles and nervous system of the fetus become mature enough for movement to occur by the ________ month of development.
26) In the prenatal diagnostic technique amniocentesis,
A) a needle is inserted into the umbilical cord to collect fetal blood for screening
B) a thin, flexible tube connected to a needle is inserted through the vagina and into the uterus to collect a tissue sample
C) fetal blood is collected directly from the chorionic villi near the cervix
D) a needle is inserted through the abdominal wall to collect amniotic fluid containing fetal cells
E) the procedure cannot be performed after the fifteenth week of gestation
27) The stages of labor, in order, include
A) dilation, contraction, and afterbirth
B) contraction, dilation, and afterbirth
C) dilation, contraction, and expulsion
D) dilation, expulsion, and afterbirth
E) amniotic rupture, contraction, and expulsion
28) Why is taking the first breath hard work for the newborn?
A) The lungs are not elastic.
B) The intercostal muscles are not mature enough.
C) The diaphragm is inflexible.
D) The surface tension within the alveoli is very high.
E) The respiratory center in the medulla is not yet mature.
29) Which organ system is not functional until birth and must become fully functional immediately?
A) excretory system (kidneys)
B) respiratory system
C) cardiovascular system
D) muscular system
E) skeletal system
30) Which cardiovascular structures in the fetus shunt blood away from the fetal lungs?
A) foramen ovale and ductus arteriosus
B) foramen magnum and ductus venosus
C) foramen ovale and ductus venosus
D) umbilical artery and umbilical vein
E) umbilical artery and ductus venosus