Invertebrate Zoology Midterm Exam 1- Fall 2015

Transcription

1 Invertebrate Zoology Midterm Exam 1- Fall 2015 Name Read through the exam before you begin. This exam consists of four (4) Parts. You must provide answers for each Part. However, you are required to answer only a SUBSET of the questions (terms, etc.) in Parts I-IV. If you answer more questions than indicated in the instructions provided for each Part, your answers will be graded in order, and you will be graded only on the number of questions you are required to answer. Feel free to use diagrams liberally. Part I. Describe one SIMILARITY and one DIFFERENCE for 5 of the following 8 pairs of terms. In each case, be certain to indicate which feature represents a similarity, and which represents a difference in both cases. (4 points each; 20 points total) 1. Polyplacophora vs. Scaphopoda 1 2. frontal section vs. longitudinal section 3. leuconoid vs. syconoid 4. meiofauna vs. epifauna 5. eucoelom vs. blastocoelom

2 6. mesoglea vs. mesenchyme 2 7. choanocyte vs. choanoflagellate 8. biradial vs. bilateral symmetry Part II. For 9 of the following 13 sets of features identify the Phylum, Subphylum, Class, or Subclass that is BEST characterized by the features provided. You may NOT use the same taxon more than once. (2 points each; 18 points total) 1. With muscles that run to nerves, rather than nerves that run to muscles 2. With captaculae, ctenidia, and feet 3. With 7 classes and a highly reduced eucoelom 4. Vulgar-named taxon with larvae that resemble loriciferans 5. Unbelievable though it seems, potentially includes both tiny wheel organ-bearing free-living species and large, gutless vertebrate parasites. 6. With a haemocoel, tentacles, and arms 7. With ctenes and cydippid larvae 8. With 2 layers of tissues and no medusoid form

3 3 9. Most newly discovered and lobster-associated 10. With hexaxons and a syncytial outer body layer 11. One of several jawed meiofaunal taxa 12. Entirely marine taxon with square medusae 13. With a true stomodeum and polyps with 6 pinnate tentacles Part III. Answer 7 of the following 12 questions (6 points each; 42 points total) 1. Using illustrated diagrams distinguish between a metanephridium and a protonephridium. 2. Provide an example of a phylum that includes species that fulfill each of the following sets of criteria. a. animals with a gastrodermis b. rhynchocoel-bearing worms c. acoelomate with some parasitic members d. animals with a cuticle e. zonite-bearing members of the meiofauna f. tiny, described in the 1980 s, with less than 50 species

4 4 3. Using labeled diagrams of schematic cross sections, distinguish between a blastocoelomate and a eucoelomate. Be certain to indicate the relative positions of the gut, body cavity (if appropriate) and all three embryonic germ layers. 4. Rank the following 6 phyla in order from 1 through 6 based on the number of species they are currently thought to include. (Use 1 for the most speciose phylum and 6 for the least speciose) Phylum Rotifera Nematomorpha Cnidaria Mollusca Ctenophora Micrognathozoa Diversity Rank

5 5 5. Identify two similarities and four differences between ctenophorans and cnidarians. Be certain to indicate which taxon exhibits which configuration of each. Similarity: Similarity: Difference: Difference: Difference: Difference: 6. Describe the most common form of respiration in detail in each of the following 3 taxa: a. Bivalves b. Pulmonates c. Platyhelminths

6 6 7. Identify three (3) potential advantages of torsion in molluscs. a. b. c. 8. Provide a simple illustration of the relationship between the mictic and amictic phases of the life cycle of a monogonontan rotifer. Be certain to indicate which stages are haploid and which are diploid and which occur during which season, etc.

7 7 9. Identify the function of the following 3 structures, organelles, or cell layers. In each case ALSO identify a taxon in which you would expect it to be found: a. pinacoderm b. osphradium c. radula 10. Dennis has been at it again collecting things. Identify the type of aquatic environment (marine or freshwater) from which each of the following of his samples was collected. However, if, based on the information provided, the sample could have come from either of these environments, indicate so. The samples are not mixtures from both environments, but in two cases, his samples include specimens (parasitic or symbiotic) that he collected from other animals within his sample. Identify these 2 samples using asterisks. a. A sample that includes a gastropod, a cycliophoran, and a poriferan b. A sample that includes a monoplacophoran (lucky him!), a ctenophore, and a kinorhynch c. A sample that includes gastrotrichs, rotifers, and a tapeworm d. A sample that includes nematodes, a gnathostomulid, and a squid.

8 8 11. a. Why are asconoid sponges generally so much smaller than leuconoid sponges? b. What is spongin? c. How do the spicules of hexactinellid sponges differ from those of calcareous sponges? 12. Using an illustrated diagram describe the circulation in a typical mollusc. Use that same diagram to illustrate the relationship between the cavities that represent the eucoelom and the circulatory system.

9 9 Part IV. Answer 5 of the following 7 questions regarding invertebrate development. (20 points; 4 points each) 1. Circle the larval stages from the following list that would NOT be able to survive in the absence of water. ephyra miracidium planula parenchymula Higgin s larva veliger amphiblastula Mueller s larva 2. Identify the phylum in which each of the following life cycle stages is found a. trochophore b. Mueller s larva c. veliger d. amphiblastula 3. a. What aspect of development is shared by ALL metazoans? b. Using simple diagrams illustrate the sequence and configuration of the early embryological stages (i.e., gastrula, morula, and blastula).

10 10 4. a. What is a gemmule? b. This stage is typical of what type of invertebrate? (be as specific as possible) 5. Identify 2 of the 3 embryonic germ layers. In each case identify a cell layer or organ system that develops from the layer you have chosen. a. b. 6. Circle all of the taxa from the following list that include at least some species in which a free swimming larval stage is responsible for dispersal. Digenea Octocorallia Nematomorpha Gastropoda Calcarea Loricifera Polycladida Acanthocephala

11 7. Use a labeled diagram to illustrate the life cycle of a diploblastic organism that undergoes sequential polymorphism. 11