31) Based on the proportions of the adult body, the 3-month fetus still shows disproportionately large
A) hands.
B) stomach.
C) head.
D) heart.
32) Division of cells in a zygote is called
A) blastulation.
B) cleavage.
C) gastrulation.
D) induction.
33) The gonads arise from what embryonic structure?
A) notochord
B) endoderm
C) splanchnic mesoderm
D) intermediate mesoderm
34) Which of the following is endodermal in origin?
A) liver
B) spleen
C) blood vessels
D) skin
35) Somites differentiate into
A) the epidermis.
B) myotomes.
C) the gastrointestinal lining.
D) muscles.
36) The sclerotome will develop into the
A) peritoneum.
B) visceral serosa.
C) vertebrae.
D) heart.
37) Splanchnic mesoderm forms the
A) heart.
B) notochord.
C) brain.
D) skin.
38) Approximately ________ percent of all children have some birth defect.
A) 0.01
B) 1
C) 3
D) 20
39) A transverse section through the 24-day embryo, dorsal to ventral, would first contact the
A) neural tube.
B) notochord.
C) somites.
D) myotomes.
40) The embryonic layer that invades the lining of the uterus and forms the placenta is the
A) trophoblast.
B) embryoblast.
C) inner cell mass.
D) endometrium.