1 Biology 4361 Name ____KEY__________ Final Exam ID __________________ December 18, 2006 Multiple Choice (one point each) mark the best answer. 1. Early after fertilization, the cortex of amphibian zygotes rotates approximately a. 30° b. 45° c. 90° d. 180° 2. In amphibian gastrulation, the first cell movement is a. involution of the pharyngeal endoderm b. chordamesodermal migration c. ectodermal intercalation d. vegetal rotation 3. In amphibian gastrulation, put the following cells in order from anterior to posterior a. pharyngeal endoderm, head mesoderm, chordamesoderm b. head mesoderm, pharyngeal endoderm, chordamesoderm c. chordamesoderm, pharyngeal endoderm, head mesoderm d. chordamesoderm, head mesoderm, pharyngeal endoderm 4. The dorsal lip of the blastopore a. establishes the dorsalventra l axis. b. selfdifferentiates. c. specifies mesodermal tissues. d. all of the above 5. After gastrulation in the amphibian, the blast ocoel becomes the a. gut b. mouth c. anus d. none of the above 6. During chick gastrulation the primary hypoblast forms from a. the secondary hypoblast. b. polyinvagination islands. c. Koller’s sickle. d. the blastocoel. 7. Hensen’s node is the chick equivalent of the amphibian a. noninvoluting mesoderm. b. primitive groove. c. pharyngeal endoderm. d. dorsal blastopore lip.2 8. A critical component of the leftright axis determination in the chick embryo is a. Nodal b. Shh c. Pitx2 d. all of the above 9. In mammals, the embryo pr oper is derived from the a. trophoblast. b. hypoblast. c. inner cell mass. d. cytotrophoblast. 10. The following would likely be found in high concentration at the a nterior of gastrulating mammals. a. Wnt b. BMP c. retinoic acid d. none of the above 11. Specification and differentiation of the ventral neural tube involves a. BMP. b. Shh. c. Wnt. d. Activin. 12. Peripheral nerves are myelinated by a. oligodendrocytes. b. Schwann cells. c. axons. d. dendrites 13. What tissues induce neural plate formation? a. neurectoderm and chordamesoderm b. lateral plate mesoderm and endoderm c. dorsal mesoderm and pharyngeal endoderm d. head mesoderm and chordamesoderm 14. Spina bifida is a condition that might be caused by failure to close the a. blastopore b. vegepore c. anterior neuropore d. posterior neuropore 15. Neural crest cell migration pathways are controlled by a. the extra cellular matrix b. chemotactic signals c. mesenchymal mesoderm d. all of the above3 16. Facial bone formation involves a. endochondral ossification b. neural crest cell ossification c. intramembranous ossification d. osteoblastic ossification 17. Bone cells that secrete collagens and other proteins that bind calcium are called a. pericytes b. periostiocytes c. osteoclasts d. osteoblasts 18. Periodic expression of _________ tr iggers somite formation periodicity. a. sonic hedgehog b. Nodal c. ephrins d. BMPs 19. The sclerotome is determined primarily by a. Sonic hedgehog from the notochord. b. MyoD from the neural tube floor plate. c. BMPs from the epidermis. d. none of the above 20. In general, somite specification involves expression of a. Hox genes. b. Wnts. c. FGFs. d. BMPs 21. Tendon formation is associated with what gene activity? a. Xnr b. nodal c. shh d. scleraxis 22. Mammalian embryos exchange food and waste through the a. chorion b. allantois c. amnion d. yolk sac 23. In mammals the embryonic aortic arches eventually form the a. pharyngeal pouches b. pharyngeal arches c. ventricles d. aorta4 24. Hemangioblasts form only a. arteries. b. arteries and veins. c. blood cells. d. blood cells and blood vessels. 25. One of the final steps in lung maturation is a. formation of larynx b. bifurcation of the bronchi c. production of surfactant protein d. lobe formation True/False (1 point each) 26. In amphibians mesoderm is induced by the animal cap cells. F 27. Mammalian embryos go through the midblastula tr ansition at the 128cell stage. F 28. In chick embryos the hypoblast is displaced by endoderm. F 29. During secondary neurulation, the neural tube originates as a solid rod. T 30. Development of neurons in the neural tube takes place in the ventricular zone. T 31. Facial cartilage is formed from the cranial neural crest cells. T 32. During endochondral ossification chondrocytes are initially replaced by osteocytes. F 33. Blood is most efficiently transported in small vessels. F 34. The pancreas originates as two lobes, which eventually fuse. T 35. Angiogenesis is the process by which the pr imary capillary network is remodeled. T Matching (1 point each) make the best connection 36. _a_ Koller’s sickle a. secondary hypoblast 37. _g_ Hensen’s node b. coelom 38. _f_ neural fold c. pharyngeal pouches 39. _j_ anterior neuropore d. angiogenesis 40. _e_ vagal neural crest e. gut enteric ganglia 41. _h_ syndetome f. medial hinge point 42. _b_ lateral plate mesoderm g. primitive streak 43. _i_ Hand1 h. tendons 44. _d_ VEGF i. heart formation 45. _c_ thyroid gland j. anencephaly5 Short answer. (5 points each; answer any six questions; be sure to answer all parts of the questions and to label and describe any diagrams) 46. How do arteries and veins manage to connect to each other (i.e. arteries to veins) and avoid attachment to the same type of vessels (i.e. arteries to arteries, veins to veins)?  arteries have ephrin (or ephrinB2) protein on their membranes  veins have the ephrin receptor (EphB4) on their membranes 47. Define ectopic pregnancy and explain why it can be a lifethreatening condition.  implantation of the blastocyst somewhere other than the uterus  the trophoblast will digest and vascularize the implantation site, leading to uncontrolled bleeding 48. What are bottle cells? Where are they found? What do they do?  embryonic cells that change into a bottle shape at gastrulation  found initially at the dorsal lip of the blastopore  lead the invagination (or involution) movement of the ectoderm 49. Explain the sta tement: “Humans are born with premature brains.”  human brain development, including addition of neurons, continues well after birth 50. Your job is to identify the gene mutation that is responsible for production of albino mice. What cells would you look at first, and why?  neural crest cells  because neural crest cells are responsible for melanocyte formation 51. Tendons atta ch muscles to bones.