Human Embryology and Developmental Biology 5th Edition – Test Bank

Human Embryology and Developmental Biology 5th Edition – Test Bank

Carlson: Human Embryology and Developmental Biology, 5th Edition

Chapter 06: Establishment of the Basic Embryonic Body Plan

Test Bank

Multiple Choice

1. A major embryonic signaling center, producing fibroblast growth factor-8 and Wnt-1 and inducing gradients of En-1 and En-2, is located at the ____________.
A. Hensen’s node
B. Midbrain-hindbrain junction
C. Notochord
D. Prechordal plate
E. None of the above

ANS: B

2. The stomodeal plate (oropharyngeal membrane) consists of _____________.
A. Ectoderm + mesoderm
B. Ectoderm + mesoderm + endoderm
C. Mesoderm + endoderm
D. Ectoderm + endoderm
E. Ectoderm only

ANS: D

3. Splanchnic mesoderm acts as an inducer of all of the tissues or organs below except:
A. Teeth
B. Trachea
C. Liver
D. Lungs
E. Pancreas

ANS: A

4. An inductive stimulus from the ____________ stimulates the transformation of the epithelial sclerotome into secondary mesenchyme.
A. Neural crest
B. Dorsal aorta
C. Ectodermal placode
D. Embryonic endoderm
E. Notochord

ANS: E

5. The primordium of which structure is located in the septum transversum?
A. Pancreas
B. Lung
C. Liver
D. Thymus
E. Spleen

ANS: C

6. Which structure consists of ectoderm directly abutting endoderm?
A. Cloacal plate
B. Amniotic membrane
C. Yolk sac
D. Neural tube
E. Placental villus

ANS: A

7. The first blood cells arise from _______________.
A. Cardiogenic mesoderm
B. Sclerotome
C. Yolk sac endoderm
D. Hindgut endoderm
E. None of the above

ANS: E

8. Sonic hedgehog, secreted by the notochord, induces the formation of the ___________.
A. Prechordal plate
B. Neural crest
C. Floor plate
D. Roof plate
E. Dorsal root ganglia

ANS: C

9. The oropharyngeal membrane breaks down in the early embryo because it is lacking in ________________.
A. Ectoderm
B. Mesoderm
C. Endoderm
D. None of the above

ANS: B

10. The major signaling molecules produced by the midbrain/hindbrain signaling center (isthmic organizer) are __________________.
A. Sonic hedgehog/Hoxa-1
B. Bone morphogenetic protein-4/En-1
C. Fibroblast growth factor-8/Wnt-1
D. Sonic hedgehog/En-1
E. Wnt-1/bone morphogenetic protein-4

ANS: C

11. _____________, produced in the notochord, induces both the floor plate and the ventromedial part of the somite.
A. Wnt-1
B. Hoxb-4
C. Chordin
D. Lim-1
E. Sonic hedgehog

ANS: E

12. Where in the embryo can you find rhombomeres?
A. Primitive node
B. Midbrain
C. Primitive streak
D. Mesoderm
E. None of the above

ANS: E

13. Mediated by sonic hedgehog, the notochord induces the ventromedial somite to form _______________.
A. Limb myoblasts
B. Pronephros
C. Muscle of the body wall
D. Vertebral bodies
E. Neural crest

ANS: D

14. The cardiogenic plate arises from ________________.
A. Embryonic endoderm
B. Somatic mesoderm
C. Splanchnic mesoderm
D. Intermediate mesoderm
E. Neural crest

ANS: C

15. Which of the following is a morphological manifestation of the craniocaudal segmentation of the embryo?
A. Splanchnopleure
B. Wolffian (pronephric) duct
C. Neuromere
D. All of the above
E. None of the above

ANS: C

16. A transcription factor characterizing cells that break away from an embryonic epithelium and become migratory as mesenchymal cells is called ____________.
A. Bone morphogenetic protein-4
B. Sonic hedgehog
C. Engrailed-1
D. Slug
E. None of the above

ANS: D

17. The dorsal pancreatic bud is initially induced from duodenal endoderm by the ___________.
A. Liver
B. Notochord
C. Lung bud
D. Yolk sac
E. None of the above

ANS: B

18. Which molecule is important in stimulating the formation of the head?
A. Activin
B. Nodal
C. Oct-3
D. Lim-1
E. Noggin

ANS: D

19. Rhombomeres are segmental divisions of the _________________.
A. Forebrain
B. Hindbrain
C. Midbrain
D. Spinal cord

ANS: B

20. The otic placode arises through an inductive message given off by the _________________.
A. Prosencephalon
B. Mesencephalon
C. Rhombencephalon
D. All of the above
E. None of the above

ANS: C

21. The sclerotome arises from cells that were located in the ______________.
A. Notochord
B. Paraxial mesoderm
C. Intermediate mesoderm
D. Lateral mesoderm
E. None of the above

ANS: B

22. Segmental structures in the developing hindbrain are called _______________.
A. Rhombomeres
B. Dermatomes
C. Placodes
D. Somitomeres
E. Somites

ANS: A

23. The oropharyngeal membrane is composed of __________________.
A. Ectoderm + splanchnic mesoderm
B. Endoderm + splanchnic mesoderm
C. Ectoderm + endoderm
D. Ectoderm + splanchnic mesoderm + endoderm
E. Ectoderm + somatic mesoderm + endoderm

ANS: C

24. The ventromedial part of the sclerotome gives rise to the ________________.
A. Pedicle of the vertebra
B. Vertebral arch
C. Distal part of the rib
D. Connective tissue around the dorsal root ganglion
E. None of the above

ANS: E

25. Blood islands form from the _______________.
A. Splanchnic mesoderm of the yolk sac
B. Endocardial tube
C. Yolk sac endoderm
D. Splanchnic mesoderm of the foregut
E. Cardiogenic mesoderm

ANS: A

26. Somites arise from _______________.
A. Somatopleure
B. Paraxial mesoderm
C. Splanchnopleure
D. Intermediate mesoderm
E. None of the above

ANS: B

27. In the elongating spinal cord of the early embryo, which molecule stimulates neuronal differentiation?
A. Retinoic acid
B. Fibroblast growth factor-8
C. Lim-1
D. Cerberus
E. None of the above

ANS: A

28. The “clock and wavefront” model refers to the formation of _________________.
A. Neural tube
B. Heart
C. Digestive tube
D. Somites
E. None of the above

ANS: D