Discussion Study Questions for Cable TV and Videotape Sections

Spring 2004

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How To Use These Questions

• Discussion question options for each test will be selected from the study questions that apply to lectures covered by that test.  The Final Exam is comprehensive over the entire semester and question list, with the provisions that at least one of the final exam discussion options will come from the questions on topics of lectures not covered by Tests 1 -  4.
• The sets of questions covered by each regular lecture test are marked below.
• The actual test questions may be shortened or otherwise edited.  The test options will not require any new information, but may call for the information to be selected from preparatory answers and presented in new arrangements.  Always read the question options on tests very carefully before choosing one and writing your answer.

• Some of these questions are not directly and simply answered in class resources.  Rather, you will have to combine information from different lectures or chapters and recognize parallels or contrasts on your own.
• Students may prefer to work together in groups on these questions, and that's okay, but be sure each person in the group fully understands every answer, rather than just memorizing answers composed by other group members.
• Good, preparatory answers to single questions need be no longer than two pages of handwritten text in length, and may be much shorter.  Only one page is provided for your answer on tests, and you should be able to fit a full answer (if well organized) into that space without writing very small.
• If you do not understand a question or term as you prepare study answers, first try the index and glossary in your textbooks.  If you are still stumped, post your question on the class WebCT Discussion Topics.  If you post questions on the discussion topics site soon enough before each test (generally, at least 12 hours before test time), Dr. Mozley will answer them.  Your laboratory insrtuctor may also be able to help you find answers.
• Trial answers should be submitted directly to Dr. Mozley by E-mail, rather than posted on the discussion topics site.  As time permits, I will comment on their completeness and accuracy.  My ability to respond will depend on how many messages I get and when they arrive.  Of course, the sooner you send them, the better.  I will do my best to respond to trial answers sent 48 hours before test time.  Please do not send your entire list for my comments, but be selective - which parts of your answers seem incomplete or uncertain?

Discussion Topics and Questions

• What properties do all cells share?
• What cell structures are unique to prokaryotic cells?
• What cell structures are unique to eukaryotic cells?
• How do the two types differ in means of locomotion?
• How do the two types differ in ways of reproducing themselves?
• In what different ways can representatives of the two types acquire energy? (e.g., photo-autotrophy)
• What way of gaining energy is unique to eukaryotic cells?

2. State the domain, and for eukaryotes, the kingdom to which each of the organisms listed below belongs, and list its distinguishing characteristics.

• This very large question would be pared down to a selection of 4 of these organisms for test purposes.
• Using the Campbell textbook, compile a list of characteristics for each domain or kingdom that differ from those of other domains or kingdoms.
• [Note that some domains and kingdoms are represented by more than one of the organisms in the list below.]
• Lists may include cell reproduction processes, the form in which genetic material is present, cell size, methods of locomotion, ways energy can be obtained, presence or absence of organelles, the number of membranes surrounding chloroplasts, chemicals used to construct a cell wall, unicellular or multicellular condition, and whether the taxon includes parasitic members.
• Scientific or common names of organisms do not count as characteristics in this question.
• Information from Question 1 also applies to parts of this question.

• green alga
• Euglena
• Paramecium (ciliate protozoan)
• Pfiesteria (dinoflagellate)
• diatom
• red alga
• Plasmodium (malarial parasite)
• colonial cyanobacterium
• extreme thermophile microbe
• Trypanosoma (cause of sleeping sickness)
• kelp seaweed
• baker's yeast
• water mold
• rusts and smuts
• mushroom
• fern
• sponge

3. Classify a human being from domain to species. (An extended version of this question is given as # 48, for the Final Exam).

• Include the following levels, in hierarchical order:  domain, kingdom, subkingdom, phylum, class, order, family, and species binomial.
• Give the names of each taxonomic level. [ For example, not just "Eukarya," but "domain Eukarya." ]
• Pay attention to spelling, capitalization, and which names should and should not be underlined.
• For the domain, kingdom, and subkingdom levels, list two characteristics that distinguish humans from other kinds of organisms at that level.

[ For example, if you were doing this for the class level, you could say that we are mammals because we have hair and because human mothers produce milk to feed their infants. ]
• For the domain, kingdom, and subkingdom levels, give the common name of another organism that is in the same taxon as us at that level, but is not in the next lower taxon that includes humans.  For example, if you were doing this for the class level, a dog would be appropriate, because dogs belong to the same class as us, but are not in our order.

4. What changes did plants undergo as they evolved for life on land?

• Build your answer around these plant types:  green algae, mosses, ferns, coniferous trees (gymnosperms), and flowering plants (angiosperms)
• What shifts have occured in the size, level of organization (unicellular, multicellular), and functional importance of gametophyte and sporophyte generations among these types of plants?
• How have these shifts made the more advanced types better adapted for life on land?
• How have other features of anatomy, reproduction and dispersal of offspring changed as plants evolved from aquatic to terrestrial habitats?

5. Are fungi more closely related to animals or to plants?

• Compare biochemical, nutritional, and cellular features among the three kingdoms.
• Why don't biologists consider plant-fungi similarities to be as important as the evidence for an animal-fungi relationship?
• Finally, list the characteristics that distinguish each of these three kingdoms from the other two. (overlaps wth Question 2)

6. Look up the following examples of mutualisms, each of which involves members of at least two different kingdoms.

mycorrhizae, rhizobia, lichens, termites, ruminant mammals, coral animals, pollinating bees, vent worms

• Give the kingdom and common names for both (or all) participants in each mutualism.
• What benefit does each participant contribute to its partner in the mutualism?

7.  What changes had to take place in a unicellular, eukaryotic ancestor before it would be classified as an animal?

• What insights into this transition can we get by comparing choanoflagellates with sponges?
• What ecological advantages did these changes confer on the first animals?
• About when (number of years ago) do biologists believe these changes occurred?

8. What advances in complexity are evident from sponges to cnidarians?  Be sure to address the following topics:

• At what level of classification are sponges and cnidarians separated, and what are the names of their respective groupings?
• How do they differ in levels of anatomical organization and skeletal support structures?
• How do they differ in cell types and functions?
• How do they differ in typical life cycle stages?
• How do these differences affect the ways they gather and digest food?
• What other, advanced structures or capabilities do cnidarians have, but sponges lack?

• tissue features,
• level of biological organization,
• sensory-motor abilities, and
• variety of cell types.
• What ecological advantages do these differences confer on bilateral animals?

10. Discuss the variations on the basic life cycle pattern that occur in the cnidarian classes.

• Which class tends to have the most complete life cycle, with the most balance between the two, feeding life stages?
• What are the biological roles of each life stage? Which carries out sexual and which does asexual reproduction? Which stages feed and grow, and which do not?  Which stage or stages are most mobile or are carried the farthest from their parental sites?
• How does the life cycle of freshwater Hydra differ from more typical members of its class?
• How does the association of different life cycle stages in a single colony in the Portuguese Man-'o-War "jellyfish" differ from a more typical member of its class, such as Obelia?
• How do true jellyfish and sea anemones represent opposite trends away from the basic life cycle?
• In what ways are the polyp stages of sea anemones and corals more like the medusa stage of Obelia?

• Which class of animal is mainly responsible for building coral reefs?
• What kind of organism (kingdom, common name) is mutualistic with these animals? How does it help them build reefs?
• What features of the environment control the global distribution of coral reefs?
• Why are coral reef communities considered so special by ecologists?
• What kinds of human activities directly or indrectly threaten coral reef survival?

12. What are the main contrasts between protostome and deuterostome embryos?

• What main variations, or evolutionary lines, occur within the protostomes, and how do they differ in adult and embryonic features?
• What are the three, main lines of bilateral animal evolution?
• What is the meaning underlying the names of each of the three groups (and of the Lophotrochozoa synonym)?
• Which of the three groups includes the animals most like the ancestor of all bilateral animals?  Explain your choice.
• What does it mean to say that deuterostomes have reversed and inverted body axes relative to protostomes?
• This part requires, at this early stage of the class, that you consider your own body as a representative of deuterostome design.
• Relative to your digestive tract, is your heart dorsal or ventral? What about your nerve cord?
• What dorsal-ventral relationship among these structures occurs in a protostome such as a mollusk or an annelid?

End of questions covered on Test 1, Spring 2004.

13. Describe aspects of  the biology of human blood flukes, human liver flukes, dog tapeworms that infect humans, and human (beef) tapeworms.

• Name and describe the separate life stages of each worm (less detail for tapeworms).
• Describe the habitats or host parts in which each life stage lives, and which stages move from one habitat or host to another.
• Which stages reproduce asexually?  ... sexually?  ... not at all?
• How does each stage obtain food?
• What form of food does it use?  [ if any ... fat may be stored from a previous stage]
• If it takes in energy, how does it do so - through a mouth, through the skin, or both?
• Which life stage infects a human?
• Where does each live in the human body, and what effects can it have on human health?
• How can you prevent yourself  from being infected by each parasite if you are in an area where it occurs?

14. What advantages might be provided by having a coelom?

• Using examples of acoelomate, pseudocoelomate, and eucoelomate animals, discuss how having or lacking a fluid-filled body cavity fits the size and habitat of that animal.
• Discuss any advantages in locomotion that eucoelomates might have over pseudo- or acoelomates.
• What other advantages for body function might a coelom provide ?

15. Describe as completely as possible the pathways of both water and food particles through the body of a typical clam or mussel.

• List the anatomical structures through which water and food pass in proper sequence, and
• Describe the changes in water (dissolved gases) and food particles (removal, sorting), if any, that occur within that structure.

16. Why do you think the Gastropoda are so successful in terms of total numbers of species?

• What habitat is occupied only by gastropods among all kinds of mollusks?  What adaptations have enabled them to live there?
• Is the gastropod method of locomotion suited to more kinds of habitats than the methods other mollusks use to move?
• What factors might keep other mollusk classes from being able to live in as many habitats and feed in as many ways?
• How might the evolution of fishes have affected the success of some types of mollusks?
• What is torsion, and what role might it play in gastropod success?

17. Compare and contrast Clitellata with Polychaeta.

• Which shared features are used to combine the two classes into the phylum Annelida?
• What are the basic contrasts in anatomy and life cycle between the two classes?
• How do their differences relate to their tendency to occupy different habitats?
• Why do specialists prefer to combine Hirudinea and Oligochaeta as subclasses of Clitellata?

18. Contrast the life cycles of freshwater and marine bivalves.

• What typical, life history stages of marine bivalves such as oysters are lost from freshwater river mussels and fingernail clams?
• What is the purpose for marine bivelves having these "extra" life stages?
• Why might freshwater bivalves (as well as freshwater annelids, flatworms, and hydrozoans) eliminate these stages from their life cycles?
• How have freshwater river mussels overcome the problem of dispersing their offspring to new sites without having a planktonic larval stage?
• How are the freshwater pest bivalves that have rsecently invaded the United States, Asiatic clams and zebra mussels, able to spread so rapidly down river systems and get into industrial water intake pipes?

19. What insights does the presence of a trochophore larval stage in a class or phylum give us about its phylogeny?

• What is the definition of a trochophore larva?
• What is its habitat and function in the life cycle of the taxa which have it?
• Which Spiralia phyla have a trochophore larval stage, and what does this stage suggest about their phylogeny?
• Why is the trochophore thought to have been discarded from the life cycle of freshwater and terrestrial species in phyla which have the trochophore in marine members?

20. What are the reasons and implications for the fact that Bryozoa (= Ectoprocta) have no organs for excretion or respiration?

• What aspects of their general body design allow them to get along without nephridia or gills?
• What limits does the lack of such organs impose on their ability to evolve new or different anatomical characteristics?
• How might this situation be related to their asexual reproduction and colonial growth form?

21. In what ways are ribbon worms (phylum Nemertea) intermediate between flatworms and mollusks?

• How are their bodies more complex than flatworms?
• Which of these aspects of greater complexity resemble mollusks, and which are unique?
• How are their bodies simpler than a chiton's?

22. Compare and contrast Nematoda and Rotifera.

• What anatomical features do they share?
• Name and describe two unique features for each phylum.
• Which phylogenetic group does each phylum belong to?
• What microscopically visible characteristics relate each of them to their respective groupings?

23.  Prepare a phylogenetic tree that includes all the following phyla:  Platyhelminthes, Rotifera, Mollusca, Annelida, Bryozoa and Nematoda.

• Draw the tree in a form similar to those presented in lectures.
• At appropriate places on the branches, write the following terms: blind gut, complete gut, acoelomate, pseudocoelomate, eucoelomate, spiral cleavage, ecdysis, metameres, mantle, chaetae, external cilia in some life stage, trochophore, op-en or closed circulatory system, forming colonies by asexual budding, metanephridia.
• Choose and explain examples of characteristics shared by two or more of these phyla (one example of each type) that are ancestral, derived, and convergent.

End of questions to study for Test 2

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Beginning of questions to Study for Test 3

24.  Compare the four Ecdysozoa phyla we are studying in ZO 150.

• What are the distinctive features of each phylum?
• What shared features of anatomy or visible behavior support the combination of the four into the group Ecdysozoa?
• What are the major differences between Nematoda and the Panarthropoda (= Tardigrada + Onychphora + Arthropoda)?
• In what ways are nematodes more like tardigrades than they are like onychophorans?
• What are the major advances in body design of arthropods over onychophorans?

25. By what criteria is Arthropoda is the most successful animal phylum?

• What other phyla are relatively successful, by these criteria?
• What features of  body design, life cycle, environmental tolerances, or other abilities can help explain the success of arthropods?
• Which particular kinds of arthropods are the most successful, by these criteria?
• What features of  body design, life cycle, environmental tolerances, or other abilities can help explain the relatively greater success of particular kinds of arthropods?

26. Recently, the arthropods formerly distinguished as subphyla Crustacea and Uniramia (= Myriapoda + Insecta) have been combined into a new subphylum called Mandibulata.  Now, there are just two subphyla of living arthropods, Mandibulata and Chelicerata.  How do the anatomical similarities and differences across the taxa Chelicerata, Crustacea, Myriapoda, and Insecta justify the recognition of these two subphyla?

• Discuss, on the basis of adult anatomy, why Mandibulata is a good phylogenetic grouping for crustaceans, insects and myriapods.  Be sure to show how members of Mandibulata are more similar to each other than any of them are to Chelicerata.
• Do you think the myriapods are more closely related to the insects or to some of the crustaceans?  Explain your choice, remembering that the process of adapting to a terrestrial environment, which could have occurred independently in insects and myriapods, might have resulted in many, convergent characteristics.

 

• What features of anatomy and life cycle stages occur in all of them?
• Do any of these shared features set them apart from the insects and myriapods?
• How many of the shared features could be convergent adaptations to a marine environment?

Then, list at least two distinctive characteristics for each class.  How does each characteristic fit a specific class for its typical habitat, method of feeding, etc.

28.  What adaptations allow most arachnids and insects to live out of the water?

• How do they reduce water loss through body surfaces?
• How do they reduce the water needed for excretion?
• How do they exchange respiratory gases without drying out?
• How do they support their weight and move over the ground without the bouyancy of water?
• How to they keep their eggs from drying out?
• How are their young dispersed to new living areas without the ocean currents that carry planktonic crustacean larvae?

29. Give examples of four economically important insects:

• two beneficial in different ways, other than biocontrol, and
• two harmful in different ways.
• What adaptations of anatomy, feeding abilities, environmental tolerances, and life cycle enable each kind of insect that you listed to become so important to us?

30. What is meant by "biocontrol" of pest insects?

• What kinds of insects are effective biocontrol agents?
• How do biocontrolling insects affect pest insect populations?
• What ecological advantages come from biocontrol, as opposed to chemical pesticides?
• What other animals might be useful as biocontrol agents?

31. Prepare a phylogenetic tree that includes all the following phyla:  Annelida, Nematoda, Tardigrada, Onychophora, Arthropoda, Echinodermata, Hemichordata, Chordata.

• Draw or paste up the tree in a form similar to to those presented in lectures, or add to the tree you made for Question 20 above.
• At appropriate places on the branches, write the following terms: metameres, ciliated larva, external cilia in some life stage, non-living outer covering that is shed in order to allow growth, lobopods (or unjointed appendages), chitinous claws, tracheal system, antennae, jointed appendages, schizocoelous, enterocoelous, mosaic (= determinate) cleavage, regulative (= indeterminate) cleavage, spiral cleavage, radial cleavage, pharyngeal (gill) slits, notochord, three coelomic compartments, mouth from blastopore, anus from balstopore, water vascular system, postanal tail, ventral nerve cord, dorsal nerve cord.
• At appropriate places on the branches, write the following classification terms:  Protostomia, Spiralia, Ecdysozoa, Deuterostomia.
• When you see a similar character show up on two, separate branches (not present on lower branches in either line), discuss whether the character is convergent or ancestral, and why you think so.

Be prepared to reproduce any part of this annotated tree as a discussion question.

32.  How are echinoderms different from other animals?

• What features of the phylum are shared by all of its classes, but not by any other animals?
• What unique adaptations occur in only 1 - 3 of the echinoderm classes?
• Choose two features of their anatomy that are not found in any other animal phylum.
• What structures in squid and crayfish perform the same functions as these unique, echinoderm features?

33. Which two of the phyla three, deuterostome phyla that we are studying in ZO 150 are most similar, and probably most closely related?

• In what anatomical and life-cycle ways are these two similar?
• Which of these similarities also occur on the thrid phylum?
• How do these two differ from each other?
• Are there any closer similarities between either of these two and the third, generally less similar, phylum?
• What differences in the evolution of each group into particular habitats or modes of feeding might explain these differences?

End of questions to study for Test 3

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Beginning of questions to study for Test 4.

• Describe embryological, larval, and adult characteristics that are consistent with the Cephalochordata-Craniata monophyletic clade.
• In each case, also describe how Urochodata differ from the Cephalochordata and Craniata.
• Describe two characteristics of Urochordata that also occur in Craniata but NOT in Cephalochordata.
• Do you think these characteristcis are convergent or ancestral?  Why?

35. Discuss the origin of vertebrae, pectoral and pelvic fins, scales, and jaws within the phylm Chordata, addressing the following points:

• What skeletal changes had to occur to allow chordates to become larger, swim more strongly, and develop more complex behaviors?
• What basic, chordate feature guided the formation of vertebrae along the notochord of the earliest fishes?
• What anatomical structures of a lancelet-like ancestor went into the formation of jaws?
• What skeletal changes had to occur to support lateral fins?
• What locomotory advantages do vertebrae and lateral fins confer?
• What new type of feeding became possible for fish that evolved jaws?
• What were the original structures in ostracoderms that became dermal scales of modern fishes?
• How were the scales around the jaws modified to make jaws more effective?

36. What anatomical similarities occur between sturgeons (members of the class Actinopterygii) and sharks (Chondrichthyes)?

• What features are shared by sturgeons and yellow perch (Actinopterygii) that are not in sharks?
• Which of the anatomical similarities between sturgeon and sharks do not occur in yellow perch?
• Is each of these latter similarities between sturgeon and sharks ancestral or convergent?
• Justify your hypotheses.

[ Remember, sharks are believed to have evolved from bony ancestors.]

37. Discuss possible reasons that Actinopyterygii have evolved the highest species diversity of any chordate class.

• How does their diversity of shapes and sizes compare with those of other chordates?
• What opportunities for high diversity are offered by their main habitats?
• What advantages do the special, actinopterygian adaptations give them in exploiting different habitats?

38. Why is the traditional class Osteichthyes considered to be paraphyletic?

• How does the combination of subclasses in "Osteichthyes" meet the definition of paraphyletic?
• What subclasses of the traditional Osteichthyes have closer relatives among tetrapods than among Actinopterygii?
• What are the anatomical evidences for their closer relationship with tetrapods?

39. In what ways are amphibians adapted for life in two habitats?

• How are they adapted for life in fresh water?
• How are they adapted for life on land?
• In what ways do the aquatic adaptations restrict them from spreading to more terrestrial habitats?

40. In what ways are ectothermous amniotes better adapted for life on land than amphibians?

• Include embryonic and adult adaptations.
• Describe how some of these adaptations increase amniotes' resistance to water loss.
• What are some other, anatomical advantages of amniotes over amphibians that are not directly related to water conservation?

41.  Trace the number of heart chambers from fish, through amphibians and lizards, to birds.

• What is the function of each chamber?
• How does the number of chambers relate to adaptation to particular body shapes and life styles?
• What advantages do birds gain from having four chambers?

42.  Why are lizards classified into the same order as snakes, instead of an order with crocodiles?

• What derived or advanced, anatomical features are shared by lizards and snakes?
• How are crocodiles different from both lizards and snakes?
• What features are shared by lizards and crocodiles that are not present in snakes?
• Why are these lizard-crocodile similarities judged to be ancestral?

43. Why is the traditional class Reptilia considered to be paraphyletic?

What group is omitted from "Reptilia," thus causing it to fit the definition of paraphyletic?

Describe two types of anatomical evidence that members of that omitted group are diapsids.

Which 'Reptilia' orders are more closely related to the omitted group than to other 'Reptilia'?

44. What skeletal characteristics of birds are adaptations to flight, or otherwise unique among diapsids?

• You should be able to identify at least 7 characteristics.

End of questions to study for test 4

Additional questions to study for the Final Exam.

45. List three features that mammals share with birds, and that are not present in ectothermous diapsids.

• What advantages do these characteristics give birds and mammals over living, ectothermous diapsids?
• List five ways in which mammals' anatomy differs from birds'.
• What advantages do mammals have over flightless birds because of these differences?

46. What is the basis for classifying placental mammals into different orders?

• Why are tooth shapes and arrangements so useful for identifying mammal orders?
• What other features of mammals are useful for recognizing different orders?
• Why are pigs and cows put in the same order, in spite of their apparent differences?
• Why aren't squirrels and lemurs in the same order, since their habitats, sizes, and appearances are similar?

47 What anatomical features distinguish:

• primates from other placental mammal orders,
• monkeys from lemurs,
• old world from new world monkeys, and
• the great apes from monkeys in general?
• At each level, what ecological possibilities are opened up or enhanced by the additional adaptations?

48. Classify a human being from domain to species. (This is an expanded version of Question 3).

• Include the following levels, in hierarchical order:  domain, kingdom, subkingdom, symmetry type, embryonic type, phylum, subphylum, mouth  development type, appendage development type, embryonic membrane type, skull type, class, birth type, order, family, and species binomial.
• Give the terms for the taxonomic levels beside each scientific name or phylogenetic group term for each group that includes us.
• For example, write not just "Eukarya," but "domain Eukarya."
• For all but the first three levels, list two characteristics that distinguish our group from other taxa at that level. (see Question 3)
• For each level, name another organism (common name acceptable) which is in the same taxon as us at that level, but is not in the next lower taxon that includes humans.