Difference between revisions of "Biology of the Vertebrates Study Questions"

Revision as of 15:01, 23 September 2009

Note: These study questions are not necessarily comprehensive, nor are they meant to be. They are meant to supplement your lecture notes as you review them, and alert you to the ways in which you should be thinking about the material, and formulate questions to test yourself. Exams will NOT be limited to the material highlighted in these questions, or their formats, so your lecture notes should be your primary reference.

Lecture 1

1. List and describe 3 applications for the study of vertebrate biology, and be sure to provide examples.

2. Which major taxonomic group of vertebrates is the most speciose? The least? What might account for these differences in numbers of species? Roughly what fraction of animals do vertebrates comprise?

3. What is “cladistics”? Define “monophyly,” and describe how this differs from “paraphyly.”

4. Define “synapomorphy” and “plesiomorphy.” Explain how a synapomorphy at one level can be plesiomorphic at another (or vice-versa). Briefly explain how it is that we (humans) are considered ‘bony fish’.

5. Where do vertebrates fit in the larger scheme of organisms?

Lecture 2

1. Describe 3 major evolutionary innovations, or trends, in the vertebrate body plan.

2. List, and briefly describe, each of the major organ systems shared by vertebrates.

3. What are ‘homologous’ bones? In which group (and roughly when in geologic time) does bone appear in the fossil record? What is bone comprised of, and how does it differ from cartilage?

4. Describe the 2 major regions of the vertebrate skeletal system (what features does each contain). Describe the 3 major embryological regions of the skull, and what what each gives rise to.

5. How does the tetrapod vertebral column differ from the ancestral condition (both in its morphology and capacity for movement).

6. Briefly explain the major transitions in the appendicular skeleton from sharks, to bony fish, to lobe-finned fish, and to terrestrial tetrapods.

7. In ancestral vertebrates, such as bony fish, axial muscles are divided into _________. What are the major regions of axial musculature called? With which features are the hypobranchial muscles associated?

Lecture 3

1. What is ‘plate tectonics’ and why does it matter for vertebrate evolution? Define ‘continental drift’ and ‘subduction,’ and provide examples for each.

2. The first fossil records are from which geologic period? How were most of the continental land masses situated during this time, and what were the environmental conditions like?

3. Describe some key features of Myllokunmingia. When did it evolve, and why this fossil is significant for vertebrate evolution.

4. When did the conodonts evolve, and how do we know?

5. Describe some key features of the ostracoderms; when did they evolve, and roughly when did they go extinct? Which group experienced a major radiation during the Silurian? Some ostracoderms had hypocercal tails, and others hetercercal tails – what does this mean? Which group is charaxterized as having brain structures similar to lampreys?

6. Describe some similarities and differences in morphology and biology between the 2 living jawless vertebrates.

7. List 6 main gnathostome characteristics. Roughly when did jaws evolve? Briefly explain Mallatt’s hypothesis regarding the evolution of jaws from jawless, filter-feeding ancestors.

8. List the 4 main gnathostome groups, present between the Silurian and Devonian. Describe some of the major characteristics of placoderms, and how they differ from, say, the ostracoderms.

Lecture 4

1. Name and describe the two major extant clades of cartilaginous fishes. How do these differ from one-another (particularly in terms of skull morphology).

2. How do modern sharks differ from their ancestral counterparts (give at least 3 major characteristics)? When in geologic time did cartilaginous fishes arise?

3. Describe the two major shark radiations. Roughly when did each occur, and how did sharks from the second wave differ from those from the first?

4. List and briefly describe some important characteristics of modern sharks, in terms of their: (a) morphology (general anatomy, shape, size range), (b) physiology (e.g., osmopregulation), and (c) reproductive biology (e.g., fertilization; oviparity/viviparity).

5. What proportion of elasmobranchs are oviparous? Describe two types of viviparous eggs.

6. From video: Describe 2 types of symbiotic relationships between sharks and other fish. True or false: sharks must keep swimming to remain alive. True or false: hammerheads actually do use their heads to bash prey. What is the largest species of shark, and what does it feed on?

Lecture 5

1. List the 3 major groups of bony fishes in the order in which they appear in the fossil record.

2. Which of the above groups do the Teleostomes comprise? Give 2 major physical characteristics shared by all Teleostomes.

3. Give 2 physical characteristics of Acanthodians, different from the ones you gave in #2 above. When did Osteichthyes appear in the fossil record? When did they undergo their most dramatic radiation?

4. What happened to all the other jawed and jawless vertebrate lineages during the radiation of the sarcopterygians?

5. Name 2 important representatives of lobe-finned fishes, and describe the general habitats they inhabit, as well as their geographic distributions.

6. Of the South American, African, and Australian lineages of lungfish, which most closely resembles the ancestral Devonian form, and what about them makes this so? How do these 3 groups differ in terms of their reliance on air-breathing?

7. Why were lungs advantageous for these lineages, and from which structure(s) were they derived?

8. Describe 2 important adaptations of lung fish; one relating to feeding, and the other to tolerating drought.

9. When was the first living coelacanth specimen discovered, and which two people are most noted for describing it? Where was it discovered? Where else have living specimens been found since? Describe an anomalous feature of coelacanth breeding biology.

10. Which group of bony fishes has experienced the largest radiation? Describe 2 (of 4 presented in lecture) ancestral, and 1 (of 2 presented) derived features of extinct Paleoniscids. By the way, how is it possible for a lineage to posses both ancestral AND derived features?

11. List the major Actinopterygian lineages (common names are fine), in order from most ancestral to most derived, along with al least one defining characteristic for each lineage.

12. Describe 2 body forms that 3 actinopterygian radiations (paleoniscids, neopterygians, and teleosts) have converged upon.

13. Briefly describe ancestral and derived conditions of bony fish jaw structures, with examples of groups that possess them, in terms of degree of upper jaw fusion with skull and mobility. What are some advantages to the derived condition?

14. In which of 2 African Rift Valley lakes (Victoria or Tanganyika) have cichlids diversified in terms of BOTH jaw structure and body shape? Of what feeding type is the ancestral cichlid presumed to be?

15. What are “species flocks”? How did was speciation initiated in these species flocks (divergence in feeding morphology, or evolution of color pattern differences through sexual selection)?

Lecture 6

1. Describe 3 features (of several discussed in lecture) that different lineages of deep sea fishes have converged upon, and explain their adaptive significance (i.e., how they are important to the organism’s fitness; what types of pressures might have selected for them). In what sense do deep sea fishes provide a counter-example to the African cichlids?

2. What are photophores, and what functions do they serve for the fish?

3. Describe some differences in gill structure and function among lampreys, sharks, and teleosts, in terms of (a) their support structures (or lack thereof), and (b) how they are aerated (i.e., water flow).

4. If you took 1107 Lab, you learned what an operculum is, but you probably didn’t learn what it does (certainly true, if you took it from me…). Now that you know so much more about it, describe its role in teleost respiration.

5. Explain the “two pump” system of teleost respiration; what are the pumps, and how do they work? What were the adaptive consequences of this innovation?

6. Describe the counter-current exchange mechanism of gill function; how does it work and what makes it so efficient?

7. What is a “swim bladder” and which structure is it derived from? What did it initial evolve for, and what was it secondarily co-opted for in some fish?

8. Describe the two types of swimbladders, and indicate which is ancestral and which is derived, and briefly explain how each functions.

9. In which types of habitats is schooling behavior more prevalent? How do fish monitor the movements of others?

10. List 2 main advantages to schooling behavior, and for each provide 1-2 lines of reasoning, complete with examples form the lecture, videos, or text. Explain the composition and significance of single- and multi-species schooling groups.

Lecture 7

1. Which of the 2 main fertilization strategies is characteristic of most fish? Explain some differences between group and pair spawners, particularly in terms of the relative costs and benefits (i.e., trade-offs) associated with each.

2. Give an example of a group characterized by internal fertilization, and describe the relevant structure(s) involved.

3. Name 2 types of eggs laid by fish, and describe them in terms of where they are laid, and their advantages and disadvantages. Provide an example for each.

4. Explain the resource defense mating system. Describe the resource defense mating system of three-spine stickleback, in terms of what constitutes the limited resource, what males fight for, and what kinds of evolutionary implications this has for the physical features of males.

5. Explain the difference between parental care-givers and cuckolders in bluegill sunfish, and when they mature relative to females. What are the two types of cuckolders, and what is the difference between them?

6. What is a “lek,’ and provide an example from the lecture, videos, or text. Describe the trade-off (or evolutionary cost/benefit) in some species that results from strong sexual selection on male coloration.

7. List some mating strategies characteristics of African cichlid species.

8. Describe sex change in the blue-headed wrasse, in terms of females, primary males, and secondary males. How long does it take to go from female to male?

9. Why is there generally an advantage to being male, and under which circumstances are primary males favored over secondary, and vice-versa? Why does investment in sperm production – in terms of GSI - decrease terminal phase, as opposed to initial phase, males?

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