Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1. |

Refer to the illustration above. Which organism is most closely related to a jellyfish?
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2. |
Which of the following distinguishes sponges from other invertebrates?
a.
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They are not motile in any stage of their life cycle. |
b.
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They obtain nutrients by diffusion rather than by ingestion. |
c.
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Their cells are not organized into tissues. |
d.
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They reproduce only asexually. |
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3. |
Sponges
a.
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are nonsymmetrical. |
b.
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lack organization into tissues and organs. |
c.
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possess cells that are capable of recognizing other sponge cells. |
d.
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All of the above |
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4. |
Collar cells
a.
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are specialized for reproduction. |
b.
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draw water into the body of a sponge. |
c.
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produce cytochrome oxidase. |
d.
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are parasitic protozoa. |
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5. |
Spicules are
a.
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flexible protein fibers. |
b.
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hard spike-like structures in the wall of a sponge. |
c.
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similar to seeds; a complete sponge can grow from each spicule. |
d.
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used for taking in food and water. |
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6. |
Adult sponges
a.
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have body walls with many pores. |
b.
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possess true tissues. |
c.
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are active swimmers. |
d.
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use stinging cells to capture prey. |
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7. |
Skeletal support in sponges may be provided by
a.
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spicules of calcium carbonate. |
b.
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spicules of silicon dioxide. |
c.
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fibers called spongin. |
d.
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All of the above |
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8. |
Sponges obtain food
a.
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through photosynthesis. |
b.
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by using their spicules to paralyze protozoa. |
c.
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by filtering small organisms from the water. |
d.
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with their spongin. |
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9. |
In sponges, currents that draw water through the organism are created by
a.
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amoebocytes. |
c.
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gemmules. |
b.
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collar cells. |
d.
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spicules. |
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10. |
The cells that move throughout the sponge’s body wall to deliver food to the organism’s cells are called
a.
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amoebocytes. |
c.
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gemmules. |
b.
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choanocytes. |
d.
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spicules. |
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11. |
Water leaves the interior of a sponge through the
a.
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food vacuoles. |
c.
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body wall. |
b.
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spicules. |
d.
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osculum. |
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12. |
collar cell : water ::
a.
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amoebocyte : nutrients and wastes |
b.
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spongin : food |
c.
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spicule : water |
d.
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osculum : mesenchyme |
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13. |
The gemmules of sponges
a.
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create water currents for feeding. |
b.
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are equivalent to the sperm cells of higher animals. |
c.
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are equivalent to the egg cells of higher animals. |
d.
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are necessary for one form of asexual reproduction. |
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14. |
Hermaphroditic organisms
a.
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reproduce only by asexual means. |
b.
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produce both eggs and sperm. |
c.
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have gemmules that are fertilized by amoebocytes. |
d.
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possess only male amoebocytes. |
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15. |
Hermaphrodism is advantageous in sponges because
a.
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they reproduce asexually. |
b.
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they have gemmules. |
c.
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they are sessile. |
d.
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None of the above is true; hermaphrodism does not occur in sponges. |
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16. |
Sponges can reproduce
a.
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by the budding of new sponges from the parent. |
b.
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by a breakup of the original parent into fragments that each become a new sponge. |
c.
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sexually, using sperm and eggs. |
d.
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All of the above |
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17. |
some freshwater sponges : gemmules ::
a.
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hermaphrodites : eggs and sperm |
b.
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gemmules : eggs |
c.
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gemmules : sperms |
d.
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amoebocytes : eggs |
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18. |

Refer to the illustration above. Which organism captures its prey using nematocysts?
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19. |
Many cnidarians have two distinct life stages,
a.
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the gametophyte and the sporophyte. |
b.
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the polyp and the medusa. |
c.
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the egg and the adult. |
d.
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the egg and the larva. |
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20. |
Nematocysts
a.
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contain harpoonlike structures called cnidocytes. |
b.
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create water currents in sponges. |
c.
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can spear a cnidarian’s prey. |
d.
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are found in most predatory ctenophores. |
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21. |
The cnidarian’s inner layer of tissue is specialized for
a.
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digestion. |
c.
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capturing prey. |
b.
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reproduction. |
d.
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All of the above |
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22. |
The outer cell layer of a cnidarian is the
a.
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ectoderm. |
c.
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endoderm. |
b.
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mesoglea. |
d.
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epidermis. |
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23. |
Which of the following is a characteristic associated only with cnidarians?
a.
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a digestive tract with a single opening |
b.
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cnidocytes specialized for defense and capturing prey |
c.
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choanocytes containing nematocysts |
d.
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a parasitic life cycle |
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24. |
sponges : fewer than three body layers ::
a.
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ctenophores : no body symmetry |
b.
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sponges : bilateral symmetry |
c.
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cnidarians : nerve net |
d.
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cnidarians : choanocytes |
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25. |
The phylum Cnidaria includes all of the following except
a.
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jellyfish. |
c.
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sea anemones. |
b.
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squids. |
d.
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corals. |
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26. |
Planula larvae of scyphozoans
a.
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result from fertilization of eggs by sperm. |
b.
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swim freely through the water. |
c.
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settle to the ocean bottom and grow into polyps. |
d.
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All of the above |
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27. |
The hydra is unique among the hydrozoans because it
a.
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is an active swimmer. |
b.
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lives in colonies. |
c.
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is strictly a marine species. |
d.
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has no medusa stage. |
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28. |
Which of the following is not sessile as an adult?
a.
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sponge |
b.
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coral |
c.
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sea anemone |
d.
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Portuguese man-of-war |
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29. |
Sea anemones are
a.
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medusae. |
c.
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larvae. |
b.
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polyps. |
d.
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eggs. |
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The diagram below illustrates the life cycle of the jellyfish.

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30. |
Refer to the illustration above. Which stage is called a planula?
a.
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1 |
c.
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3 |
b.
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2 |
d.
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None of the above |
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31. |
Refer to the illustration above. Which stage reproduces asexually?
a.
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1 |
c.
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3 |
b.
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2 |
d.
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None of the above |
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32. |
Anthozoans include
a.
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jellyfish. |
b.
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hydras. |
c.
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the Portuguese man-of-war. |
d.
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sea anemones and corals. |
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33. |
Scyphozoans, such as jellyfish, spend most of their lives as
a.
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polyps. |
c.
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corals. |
b.
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medusae. |
d.
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parasites. |
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34. |
The class of cnidarians that typically live only as polyps is the
a.
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Anthozoa. |
c.
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Scyphozoa. |
b.
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Hydrozoa. |
d.
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None of the above |
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35. |
Which of the following is not a characteristic of ctenophores?
a.
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bioluminescence |
b.
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movement by means of beating cilia |
c.
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use of cnidocytes to capture prey |
d.
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hermaphrodism |
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Completion
Complete each statement.
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36. |
____________________ is drawn into a sponge through pores and leaves through the osculum.
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37. |
A network of tough, flexible protein fibers called ____________________ provides support in some sponges.
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38. |
Spike-like objects that make up the skeleton of some sponges are called ____________________.
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39. |
A sponge’s ____________________ may be composed of either calcium carbonate or silicon dioxide.
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40. |
Food molecules are carried throughout a sponge’s body by ____________________.
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41. |
Food-filled balls of amoebocytes that are involved in asexual reproduction in sponges are called ____________________.
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42. |
An organism that produces both eggs and sperm is called a(n) ____________________.
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43. |
A free-floating, gelatinous body form of a cnidarian is called a(n) ____________________, while an attached body form is called a(n) ____________________.
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44. |
Cnidarians have two cell layers, the epidermis and the ____________________.
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45. |
A coral is a member of the class ____________________.
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46. |
Ctenophores are the largest organisms that move by the beating of ____________________.
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