Comparative Chordate Exam Questions Embryology 1. Describe the position and orientation of epimeric, mesomeric, and hypomeric mesoderm in a vertebrate embryo. Describe the differentiation of the epimeric (or mesomeric or hypomeric) mesoderm.
2. Know the origins of each of the embryological dermal layers (ectoderm, mesoderm, and endoderm) and what they ultimately become.
3. Define the following terms
4. Understand/describe the origin and composition (germ tissues) of extra embryonic membranes, somatopleure, and splanchnopleure.
5. Understand/describe chorioallantoic and choriovitelline placentas, which organisms have which type(s).
6. Know the different types of interactions between embryonic placentas and maternal uterine tissue including epitheliochorial, syndesmochorial, endotheliochorial, hemochorial, and hemoendothelial.
Integument 4. Define the following terms
5. What are the evolutionary descendants of the cosmoid scale? Name at least four and how they are derived.
6. Where evolutionarily does stratum corneum appear? Why?
7. Contrast bird and mammal skin (or any two classes of vertebrates)?
8. What is the difference between the horn of a cow and that of a pronghorn (or any two types of "horns")?
9. Know the relative importance of epidermis and dermis among the vertebrate classes. Be able to support this pattern with examples of structures or layers derived from each layer of the integument.
10. What is keratin? Elastin? Collagen? Where are they found? In which structures are they important?
11. Using an example of the development (ontogeny) of vertebrate teeth, describe the difficulty of talking about clearcut differences between epidermal and dermal structures.
12. What layers of tissue were evolutionarily lost in the development of a mammalian tooth from a cosmoid scale?
13. What are the relationships (if any) among fish scales, reptile scales, feathers and hair.
Skull 14. Be able to identify the origins of any skull bones as to dermal bone (dermocranium), visceral bone (splanchnocranium), or endochondral bone (cartilage replacement bone / neurocranium).
15. Know the basic parts of an ancestral jawed vertebrate. Bone names, which visceral arch is which, what bone become in more derived classes of vertebrates.
16. Why do fenestrations appear in the dermal bone (dermocranium) of some reptiles?
17. Draw and label the bones of an anapsid reptilian skull. Be able to draw in the fenestrations for each of the other reptilian skulls.
18. Know differences in the structure, and similarities in function among vertebrate skulls.
19. How does the cranio-vertebral joint of an amphibian differ from that of a mammal.
20. What is the adaptive significance of the kind of jaw suspension found in most sharks? What is this type of jaw suspension called?
21. Know the fates of the first three branchial arches through the vertebrate classes.
22. Know the kinematic attributes of bird, lizard, and snakes skulls. Be able to label bone and show function of kinematic chains.
23. Show with a simple diagram the meaning of a hyostylic suspension. In what living vertebrate classes do you see it? What is its adaptive significance?
24. Draw the skull and lower jaw of a pelycosaur. Show the vector of force applied by the jaw closing muscle. Show how this jaw could not deliver a hard bite. Why does the head (capitum) of a rib articulate between vertebral centra in mammals?
25. Describe the cranio-vertebral joint of a mammal and explain how it allows for stability and mobility.
Post Cranial Skeleton 26. With what does the tuburculum of a mammalian rib articulate? The capitum?
27. Where evolutionarily and why does an interclavicle appear?
28. What kind of centrum would most limit rotation between centra? Where do you see it?
29. With respect to stabilization of the pectoral girdle, how do fish, amphibians, reptiles, and mammals solve the problem?
30. Know all the bones in the pelvic and pectoral girdles of different classes of vertebrates. Know the origin of each bone: dermal or endochondral.
31. Know the differences between ornithischian and saurischian pelvic girdles.
32. Draw a transverse section through the trunk region of a jawed fish and show where dorsal and ventral ribs are found. Label appropriate structures.
33. Diagrammatically show the evolutionary changes in the centrum of trunk vertebrae in the evolutionary line from labyrinthodont to mammal. Label parts and show points of rib attachment on the vertebrae.
Muscles 34. Know the embryological origins of major types of muscle such as hypobranchial
muscle, epaxial muscle, branchiomeric muscle, extrinsic muscles of the eye.
35. Know the extrinsic muscles of the eye; their names, their positions, and which nerves
36. What are two evolutionary trends shown in the evolution of the axial musculature of
tetrapods? Consider the differences you see when comparing a fish to an
amphibian or amphibian to reptile/mammal.
37. List characteristics and innovations (if any) seen in the postcranial axial musculature of
the following vertebrates groups: Agnatha, Osteichthyes, Amphibia, & Reptilia.
Gastrointestinal System 44. Draw and label a rough depiction of a general vertebrate GI tract. Shade in the portions of the system found in all vertebrates. Be able to characterize any major group of vertebrates by describing which features are present (+) or absent (-). Label the hindgut and the foregut.
45. What are the probable initial functions of the vertebrate stomach?
When and why do salivary glands appear evolutionarily in vertebrates?
46. How have sharks solved the problem of the need for increased surface area in the intestine? How have other tetrapods solved that same need?
47. Sketch and label a cow stomach.
48. List the regions of the mammalian stomach and the secretory products of each.
49. In what vertebrate group would you find an intestinal caecum?
Urogenital System 50. Define:
51. Show diagrammatically the functional unit of a typical vertebrate kidney and label important structures. How is this unit modified in birds and mammals to help them cope with water loss problems (single sentence).
52. Discuss the embryological origins of kidneys in vertebrates? Describe their embryological development (timing and appearance) and which groups of vertebrates have which kind of kidney.
53. Show diagrammatically how sex cell and urinary products are carried externally in 1) a male and female primitive gnathostome and 2) a male and female mammal. List three subdivisions of the female reproductive duct system in the mammal.
54. What is the embryological origin of gonadal tissue. What is unique about the origins of sex cells?
55. Describe the differences between the development of the gonads in male and female vertebrates. What do the sex share developmentally? At what stage of development do the sexes begin to differentiate? How does development proceed after divergence for each sex?
Respiratory System 56. With graphs show the differences between countercurrent and concurrent exchange systems in terms of how they facilitate transfer of O2 from external water to the circulatory system of a vertebrate.
57. Show with diagrams how a fish with opercular gills ventilate water over gas exchange surfaces (You may make a descriptive statement about each figure - keep it brief).
58. Show with diagrams how an anuran amphibian ventilates (descriptive statements should be brief).
59. Where does most gas exchange take place in a bird lung? What is unique about the flow of air there?
60. List four major advantages and disadvantages in using air instead of water as a respiratory gas source.
61. What is the major trend seen in the lungs of vertebrates from amphibians through mammals (omit birds).
62. What does the term physostomus mean?
63. In vertebrate gas exchange where do you see countercurrent exchange? Why?
64. List to non-gill systems used by vertebrates to exchange gas with water. Which vertebrates have them?
65. What is the major difference between ventilation in a shark and a teleost?
Heart / Circulatory System 66. Define
67. How is venous return facilitated in Elasmobranch fish? (What does the pericardium and sinus venosus have to do with it?)
68. What is the conus arteriosus? Bulbous arteriosus? What do they do?
69. What are two possible functions of a trabeculate ventricle?
70. What is the anatomical and functional difference between A-V and S-L valves?
71. What does the spiral valve in the conus of the African lungfish do?
72. Discuss why the Chelonian heart is not fully subdivided and how it manages to keep blood separate. Use diagrams.
73. For a 1) bony fish, 2) salamander, 3) non-crocodilian reptile, and 4) mammal show diagrammatically the chambers of the heart, vessels leading from the heart, arrangement and number of aortic arches, and the coalescence of these arches into major vessels such as the dorsal aorta & carotids. Label heart chambers, arteries, and number arches. A dorsal or ventral view (label) would be best.
74. What is the Foramen of Panizza and what does it do?
75. What is the functional significance of a hepatic portal system? What vertebrates have it?
76. Why do some vertebrates have a renal portal system? How do mammals get by without one?
Nervous System 77. Understand and explain the differences between somatic vs visceral, afferent vs efferent, motor vs. sensory nerves.
78. Diagram the structure of a neuron and label its parts.
79. Explain how nerve impulses are transmitted. Explain the role of myelin, Schwann cells, and Nodes of Ranvier.
80. Explain how nerve impulses are transmitted form one nueron to the next.
81. Diagram how different types of nerve enter and exit thew CNS through dorsal and ventral roots.
82. Describe the development of the brain from the anterior portion of the spinal cord. Explain the development of primary vesicles, secondary vesicles and what each ultimattely becomes.
83. List and name the cranial nerves found in a mammal.
84. Which of the above question are classified as special somatic sensory? What is unusual about two of them in terms of where their cell bodies are located?
85. Where (evolutionarily) does nerve XII show up and why? In what group of modern tetrapods is it missing?