Download Biology 212: February 7, 2003

Biology 212: February 25-March 5, 2004
Invertebrate Zoology Questions
NOTE: Don’t forget that the final exam is cumulative, although the emphasis will be on the part of the
course that has not yet been covered in previous exams.
RECOMMENDATION: Before you go through these study questions, attempt to master your notes and
then use these questions to test yourself. If you simply try to write down and memorize the answers to
these questions, you will have a somewhat disjointed perspective of the course material. Once you’ve
attempted to answer the questions, use your lecture guide, notes and text to provide feedback for the
correctness of your answers.
1. List all the major invertebrate phyla covered in this course. Then, refer to your list as you answer the rest of
these questions. (You should get 10, including Phylum Chordata, which contains both invertebrates and
vertebrates). Note that since the Ctenophores were barely covered, you shouldn’t worry about them except
for knowing where they appear in the phylogenetic tree.
2. What are the five key characteristics shared by all members of Kingdom Animalia? Of these, which (if any)
is/are unique to Kingdom Animalia?
3. Your text mentions that both muscle and nerve tissue are unique to animals. Why are they not appropriate
answers to #2? Think carefully about all phyla of animals.
4. Is the Kingdom Animalia currently thought to be monophyletic (in other words, that all animals originated
from one common ancestor) or polyphyletic (animals originated from more than one ancestor)?
5. From the monophyletic perspective, from what type of organism is Kingdom Animalia supposed to have
evolved? Name its Kingdom (pre-Animalia) as well as the more specific name of the organism, and briefly
describe it.
6. What single feature separates members of Phylum Porifera from their protistan ancestors?
7. Describe the key developments which are hypothesized to have occurred at each of the major branch points as
the Kingdom Animalia evolved, according to the traditional model of phylogeny (i.e. body plan
characteristics). In addition, explain the adaptive significance of each of the “new” or “derived” features for
the animals (i.e. how does it aid in the animal’s existence?). You should also know where each of the phyla
we studied should be placed on this evolutionary continuum.
8. [NOTE: This question approaches similar concepts to the previous one, but in a slightly different
way.] Consider the developmental characteristics and proposed evolutionary relationships of the
animal phyla we studied. You should know:
 symmetry
 number/type of tissue layers (or whether it has them at all)
 body cavity: whether it exists, and type
 considered Protostome, Deuterostomes or neither
9. Explain the difference between acoelomates, pseudocoelomates and coelomates. What are some
advantages of having any body cavity (pseudocoelom or coelom) over being an aceolomate? What
anatomical feature of a true coelom is missing in the pseudocoelom, and why is this feature
important?
 You should know which phyla have no body cavity, which have pseudocoeloms, and which have
coeloms.
10. Describe the major developmental differences between protostomes and deuterostomes.
11. Which phyla have members with no digestive systems? Incomplete digestive systems? Complete
digestive systems?
12. Which phyla have members with circulatory systems? If they do have a circulatory system, is it
open or closed? Note if this differs amongst different classes within the phyla (to the level discussed
in class). (HINT: Think about the mollusks.)
13. Where does gas exchange occur in members of each group studied? You should know the key
structures for gas exchange in phyla that do have specialized structures.
14. Compare the nervous systems of the major animal phyla studied.
 Which one has no nervous system?
 Which have brains (or some sort of “cerebral ganglia”) in the animal’s anterior region?
 Which ones have direct pathways (i.e. nerve cords composed of multiple neurons) for nerve
conduction?
 Which one has nerve nets?
 If they have nerve cords, are they paired, singular, or something else? Dorsal or ventral?
 Which invertebrate is considered to have the most highly developed brain (name the organism,
not the phylum, since members of this phylum vary greatly in their brain sizes)!
15. What are the functions of each of the following cell types or structures in a sponge? Some or all may have
more than one function.
 Choanocyte (two major
 spicule
 amoebocyte
16. Describe how water moves through a sponge, naming the major pores through which it passes as well as how
the water current is generated.
17. Describe how a choanocyte is able to obtain and ingest food particles.
18. How does a sponge protect itself?
19. In terms of body plan, in what two key ways do Cnidarians differ from Poriferans?
20. What are the two cnidarian body forms? How are they similar? How do they differ?
21. What is mesoglia?
22. What is a cnidocyte? Briefly describe the structure of cnidocyte. Be sure to include specialized parts
(trigger, nematocyst, operculum.) Also explain what is meant by the "firing" of a nematocyst, and
briefly describe how the nematocyst inflicts pain.
23. What are the three major functions of the gastrovascular cavity in cnidarians?
24. How do Cnidarians and Platyhelminthes eliminate waste from their digestive system without a
separate anus?
25. Some Cnidarians, such as Obelia (Fig. 33.7) alternate between polyp and medusa forms. (I
specifically mentioned that jellyfish do this, but anemones and corals do not.) Within this type of life
cycle:
 Which (polyp or medusa) reproduces asexually?
 Which reproduces sexually?
 Which is produced asexually?
 Which is produces sexually?
26. Explain the adaptive value of having a life cycle with both a polyp and a medusa phase.
27. Briefly describe feeding in Planaria.
28. Do flatworms have a system for regulating water/ion balance?
29. How does a flatworm move?
30. How does fertilization occur for the marine flatworms seen in the video?
31. What is unusual about the penis of some Platyhelminthes compared to other phyla of animals?
32. Why doesn’t a tape worm need a digestive system?
33. To what phylum does the parasite Schistosoma belong? How do humans acquire it?
34. Why can nematodes move only in a side-to-side motion (as I demonstrated), but not forward or
backward?
35. Name three diseases caused by nematodes.
36. What characteristic distinguishes Phylum Annelida from other worm phyla introduced before it?
37. What enables an annelid to move forward by peristalsis, whereas a nematode cannot?
38. Name the three three classes of Phylum Annelida and be able to recognize representative members.
Also, be able to compare them in terms of:
 parapodia
 setae (hairs or bristles)
 extent of head development (sensory structures, etc.)
 level of segmentation (both external and internal)
39. Why are earthworms important ecologically?
40. How do earthworms and leeches feed? In other words, what feeding mechamism do they share in
common?
41. Name three substances secreted in blood-sucking leech saliva that help it to feed more effectively?
42. Know the features of the major features of molluscs, as described for the Hypothetical Ancestral
Mollusc (HAM), both structures and functions. For example, you should know where the mantle is
and what it does.
43. What is a radula? Why doesn't the radula wear out?
44. What is the major structure for gas exchange in a mollusc?
45. What type of circulatory system (open or closed?) do most molluscs have? For which class is this not
true, and why is this difference important to members of that class?
46. Be able to name and give examples of the four major classes of Phylum Mollusca.
47. For each of the four major classes of Phylum Mollusca, describe whether, and how, the major
molluscan features differ from HAM. (HINT: Make a chart that lists the major molluscan classes
and the key characteristics of HAM. Then fill out similarities/differences on the chart.)
48. What, precisely is "torsion"? Which class of Phylum Mollusca undergoes torsion? What adaptive
advantages does torsion confer? What "new" problem did torsion create?
49. What are the three basic arthropod features?
50. Besides the exoskeleton, name several other structures composed of cuticle.
51. What is molting? Why do arthropods molt?
52. What enables the new exoskeleton to become larger than the old one, even though the new
exoskeleton is produced beneath the old one?
53. Describe basic feeding in crustaceans and insects, as well as some variations on these feeding
mechanisms, for each.
54. Describe how a spider feeds, being sure to include the function of key parts, and how food gets into
its stomach.
55. What type of circulatory system do arthropods possess? What is unusual about the circulatory system
of Class Insecta?
56. Name and briefly describe the respiratory organs/systems of each of the major groups of arthropods.
57. What is the major site of water/ion balance in crustaceans? What is the major site of ammonia
excretion in the crustaceans?
58. What are Malpighian tubules? Where do they start and where do they empty? What is the adaptive
value of emptying into this particular location?
59. Describe the nervous system organization of an arthropod. Is the nerve cord dorsal or ventral? Are
there ganglia? A brain?
60. What is a spermatophore?
61. In insects, how is it possible for fertilization to occur at a different time than mating?
62. Describe the four key features of Phylum Echinodermata.
63. Why is the skeleton type of Phylum Echinodermata considered to be an "endoskeleton"? Compare
this to an "exoskeleton".
64. What are two functions of the water vascular system? From what is it derived?
65. Describe the symmetry of larval echinoderms compared to the symmetry of adults.
66. List the five major classes of Phylum Echinodermata we studied, and name representative members
of each. Also, be able to recognize them from a picture or from key parts unique to a particular
group.
67. Know how different echinoderms feed, what their major structures for gas exchange are, and how
they protect themselves.
68. Be sure you know the appearance, location and functions of the following echinoderm structures, and
in which groups you find each (HINT: review lab as well as lecture).
 spines
 tube feet
 pedicellariae
 dermal papulae
 ambulacral groove
 Aristotle's lantern
 madreporite
 water vascular system
 peristomial gills