Here are some practice questions on the material covered in Lectures V-VII. Each multiple choice question has a single correct answer. I suggest you attempt to answer all of the questions before checking the answers.

1. Whereas the first organisms were most likely ________________ , the oldest known microfossils appear to have been ________________ similar to contemporary ______________.


2. The oldest microfossils are believed to have been
   1. aerobic heterotrophs
   2. anaerobic hetetrotrophs
   3. anoxic or oxygenic autotrophs
   4. methanogenic archaebacteria
   
   
3. Aerobic heterotrophs supplement ___________ with the __________. The result is the production of additional __________.


4. Anoxic autotrophs that get their electrons from H₂S oxidze this compound to ___________. By way of contrast, oxygenic autotrophs get their electrons from ___________ which they oxidise to ___________.


5. Stromatolites
1. Have existed since the Precambrian
2. Formed reef-like structures with photosynthetic bacteria in the upper layers
3. Contributed to the oxygenation of earth's atmosphere
4. Are vulnerable to invertebrate grazers such as snails and worms
5. All of the above


6. Complete the following sentences (based on Table 5.1):

   1. Fermentation	1. 2 ATP molecules
   2. Aerobic metabolism	2. 36 ATP molecules
   3. The energy yield of fermentive metabolism (per molecule of glucose "crunched") is	3. entails the production of pyruvate by glycolysis and the conversion of pyruvate to lactic acid or ethanol.
   4. The energy yield of aerobic metabolism (per molecule of glucose "crunched") is	4. the hydrogen donor is water
   5. In oxygenic photosynthesis,	5. combines glycolysis with the citric acid (Krebs) cycle and the respiratory (electron transport) chain.



7. Oxygenic photosysntheis may have arisen as early as as 3750 Mya. This conjecture is supported by the observation of which of the following kinds of rocks or minerals that date from this time?
1. Banded iron formations
2. Pyritic conglomerates
3. Redbeds
4. Sedementary rocks called shales
5. Shocked quartz


8. Large scale oxygenation of the earth's oceans and atmosphere was required the evolution of ____________.


9. The greatest ecological crisis in the earth's history was most likely
1. caused by the accumulation of oxygen in the earth's waters and atmosphere during the Precambrian.
2. caused by an asteroid impact at the end of the Cretaceous.
3. the "mother of all mass extinctions" at the end of the Permian.
4. the extinction of large mammals (megafauna) at the end of the Pleistocene — probably the result of human hunting.


10. List five differences between eukaryote and prokaryote cells.


11. The "cost of sex" refers to
1. Inherent inferiority of males.
2. Greater metabolic cost of producing male offspring.
3. Parthogenetic populations of females can reproduce twice as quickly as sexual populations consisting of half males and half females;
4. a. and b.
5. a. and c.


12. Diversification of eukaryotes approximately 900 mya may have been due to
1. Evolution of the eukaryote flagellum.
2. Increased availability of nutrients in the earth's waters.
3. Evolution of ribosomes.
4. Evolution of chlorophyll a.
5. Evolution of sex.


13. Which of the following groups have bodies composed of two cell layers?
1. Sponges.
2. Ctenophores.
3. Lophotrochozoans.
4. Ecdysozoans.
5. Deuterostomes.


14. Which of the following distinguishes protostomes from deuterostomes?
1. Sprial vs. radial cleavage.
2. Two cell layers vs. three.
3. Bilateral vs. biradial symmetry
4. Different developmental fates of the embryonic blastopore.
5. Closed vs. open circulatory system.


15. Which of the following groups are protostomes?
1. Echinoderms.
2. Ctenophores.
3. Cnidaria.
4. Insects.
5. Sponges.


16. Which of the following groups are deuterostomes?
1. Echinoderms.
2. Ctenophores.
3. Cnidaria.
4. Insects.
5. Sponges.


17. Which of the following explanations was favored by Darwin as explaining the sudden appearance of most of the major taxonomic groups at or near the base of the Cambrian?
1. Coevolutionary arms race between predators and prey that resulted in rapid morphological diversification.
2. Dearth of Precambrian sedimentary rock in which fossils might be found.
3. Increasing genetic complexity.
4. Increasing levels of molecular oxygen in sea water.
5. Precambrian animals abundant but not preserved as fossils.


18. Which of the following statements is correct?
1. Paleontology and molecular biology give roughly the same answers regarding the times at which the major taxa first diverged.
2. Paleontology and molecular biology give very different answers regarding the times at which the major taxa first diverged.
3. Neither paleontology nor molecular biology give sensible answers regarding the times at which the major taxa first diverged.
4. Paleontology suggests that the major phyla extant today evolved gradually during the first several periods of the Paleozoic era.
5. Molecular biology suggests that the major phyla extant today evolved gradually during the first several periods of the Paleozoic era.


19. Molecular evidence suggests that the major phyla diverged
1. at the base of the Cambrian.
2. after the Cambrian.
3. before the Cambrian.
4. during the Cambrian.


20. The only major group of extant metzoa generally agreed upon to be represented in Precambrian assemblages such as the Ediacara Hills fauna are the _______________ .


21. One opinion as to the nature of Ediacaran organisms is that
1. they were giant plasmodial protozoans.
2. they consitute a "failed experiment" that left no descendents.
3. they evolved into modern organisms.
4. a. and b.
5. a. and c.


22. What is the Burgess Shale assemblage and what is its significance?


23. List three morphophological characters that are used to distinguish the major groups of metazoa?


24. Which of the following has not been suggested as the cause of rapid diversification of metazoa during the early Paleozoic?
    1. Increasing concentrations of O₂ which made possible the secretion of hard parts.
    2. Increasing genome complexity, e.g., Hox gene duplication.
    3. Evolutionary changes that resulted in increasing predator proficiency.
    4. Evolutionary changes that resulted in increasing victim proficiency.
    5. The evolution of photosynthesis.
    
    
25. Cephalization is _______________.


26. The three major groups of cnidarians are _________, _____________ and ___________.


27. George Bidder showed that the oscular diameters of sponges are adjusted to
1. maximize waste product - nutrient exchange before water leaving the sponge re-enters through the pores.
2. maximize the velocity of water leaving the sponge.
3. maximize the mass of water leaving the sponge per unit time.
4. a. and b.
5. b. and c.


28. Which of the following would you expect Bidder's conclusions to hold for?
1. All sponges.
2. Sponges living in a current.
3. Sponges living in still water.


29. Cnidarians manifest an alternation of generations between __________ and ___________ stages. Sexual reproduction, which results in the production of a planula larva, is generally confined to the __________ stage.
1. solitary; colonial; colonial
2. colitary; colonial; solitary
3. hydroid (polyp); medusoid; hydroid
4. hydroid (polyp); medusoid; medusoid


30. Corals are unable to live in deep waters because
1. They can't withstand the pressure.
2. The photosynthetic algae that live within their tissues cannot photosynthesize at cold temperatures.
3. There are insufficient nutrients in deep water.
4. None of the above.


31. Darwin's explanation for the existence of coral atolls in deep water entailed a balance beween ______________ and __________________.


32. Which of the following distinguish cnidaria from ctenophora?
1. Two vs. three cell layers.
2. Incomplete vs. complete guts.
3. Nematocysts vs. tentacles
4. a. and b.
5. b. and c.


33. Lophophores occur in
1. only the lophophorate lophotrochozoans.
2. in brachiopods.
3. in lophophorate spiralians.
4. a. and b.
5. a. and c.


34. Flatworms have ________; rotifers, ____________ and mollusks, _________.
1. no coelom; a pseudocoelom; a true coelom.
2. no coelom; a true coelom; a pseudocoelom.
3. a pseudocoelom; no coelom; a true coelom.
4. a pseudocoelom; a true coelom; no coelom.
5. a true coelom; a pseudocoelom; no coelom.


35. Which of the following lophotrochozoans manifest spiral cleavage during development?
1. Flatworms.
2. Rotifers.
3. Brachiopods.
4. Oligochaetes (earth worms).
5. Phoronid worms.


36. Cuvier's description of annelid circulatory systems led Lamarck to conclude that
1. Linnaeus' original taxon, vermes (worms) would have to be split into two or more taxa.
2. annelids would have to be lumped with vertebrates, which also have closed circulatory systems.
3. that it might not be possible to arrange the major taxa ladder-like in order of increasing complexity.
4. a. and b.
5. a. and c.


37. Ecdysozoans grow
1. by adding new compartments to their shell.
2. by molting.
3. continuously.
4. in spurts.
5. b. and d.


38. Flatworms are both
1. acoelous and pseudocoelous.
2. free living and parasitic.
3. metameric and unsegmented.
4. a. and b.
5. None of the above.


39. True or false: Tapeworms lack a digestive system.
1. True
2. False


40. Brachiopods are superfically similar to which group of mollusks ____________.


41. In cephalopods, the ___________ is modfied to form a siphon that allows the animal animal to expel a jet of water that propels the animal rapidly throgh the water.
1. mantle
2. foot
3. visceral mass


42. Mollusks possessing an image-forming eye similar to that of vertebrates can be found in which of the following groups?
1. Chitons.
2. Clams.
3. Snails.
4. Squids and octopi.


43. Which of the following contrasts distinguish arthropods and vertebrates?
1. Ventral vs. dorsal nerve cord.
2. Open vs. closed circulatory system.
3. Metameric (segmented) body plan vs. lack of segmentation.
4. a. and b.
5. a., b. and c.


44. Which of the following contrasts distinguish annelids from arthropods?
1. Ventral vs. dorsal nerve cord.
2. Open vs. closed circulatory system.
3. Metameric (segmented) body plan vs. lack of segmentation.
4. a. and b.
5. a., b. and c.


45. Which of the following characters distinguish echinoderms from chordates?
1. Exoskeleton vs. endoskeleton.
2. Filter feeding vs. active pursuit of prey.
3. Pentameral vs. bilateral symmetry in adults.
4. Sessile vs. active life style.
5. All of the above.


46. Sea stars have
1. a water vascular system which they use for locomotion and gas exchange.
2. an eversible stomach which can be inserted between the valves of their molluscan prey, the soft parts of which are then digested in situ.
3. ciliated larvae that are bilaterally symmetric.
4. a. and b.
5. a., b. and c.


47. If the stem deuterostome was bilaterally symmetric, pentameral symmetry in echinoderms must be a(n) ________________ trait.
1. ancestral
2. convergent
3. derived
4. evolved
5. particular


48. The hemichordate character suggesting chordate affinities is _____________ that facillitate _____________.

 

49. Vertebrate trunk muscles are arranged in ">-"shaped bundles called myomeres that attach to sheets of connective tissue, called myocommata. The latter, in turn, are anchored to the _______________.
1. dorsal nerve cord
2. neural arches of the vertebral centra
3. notochord
4. spinal cord
5. vertebral column


50. Label the organs marked a. - f. in accompanying figure of an archetypal vertebrate.
    


51. Which of the following statements regarding early vertebrate gills is correct?
1. They were widely used in both filter feeding and respiration.
2. They were used principally in respiration.
3. They were used principally in filter feeding.


52. Which of the following statements regarding contemporary vertebrate gills is correct?
1. They are widely used in both filter feeding and respiration.
2. They are used principally in respiration.
3. They are used principally in filter feeding.


53. The vertebrate jaw evolved from
1. bony structures surrounding the mouths of primitive chordates.
2. the gill arches of jawless fish.
3. the proboscis of hemichordates (acorn worms).
4. the tunicate endostyle.
5. the cephalochordate hypopharynx.


54. The tunicate endostyle
1. produces mucous that extracts food from water as it passes though the gill basket.
2. is involved in iodine metabolism.
3. has been suggested to be the organ from which the vertebrate thyroid gland evolved.
4. all of the above.


55. What is the modern day version of Haeckel's Ontogenetic Law? What was the original form?


56. Give two examples from vertebrate evolution that illustrate the modern day version of Haeckel's Ontogenetic Law.


57. What is the neotenic theory of chordate origins?


58. What is the evidence for the neotenic theory of chordate origins?


59. The accompanying sagittal section of a hypothetical vertebrate ancestor has five of the labels replaced with the letters a.-e. Associate each letter with one of the following structures: aortic arches; dorsal nerve cord; heart; notochord; gill slits.



60. An important theme in early vertebrate evolution was progressive
1. enlargement of the higher centers of the brain.
2. integration of the visceral and somatic parts of the body.
3. integration of the voluntary and autonomic nervous systems.
4. reduction of the anal and caudal fins.
5. reduction of the gills.


61. Which of the following statements regarding vertebrate lungs and swim bladders is true?
1. Swim bladders came first.
2. Lungs came first
3. Both structures are found in the earliest vertebrates.