Invertebrates Key Part I

ANIMAL EVOLUTION--THE INVERTEBRATES SHORT ANSWER 1. Cone snails produce a cocktail of paralytic secretions called (1)____________________. These peptides shut down (2)____________________ in the cell membranes of their victims. One peptide is one thousand times more potent than (3)____________________ yet not addictive and is being tested for pain relief in cancer and AIDS patients. All cone snails produce (4)____________________, which catalyzes an early step in conotoxin production. Humans also produce this enzyme, but in us it functions in (5)____________________. This enzyme is also found in insects. It is estimated that the gene has been around for at least (6)____________________ years, when these three groups shared a common ancestor. ANS: 1. 2. 3. 4. 5. 6.

conotoxins channel proteins morphine gamma-glutamyl carboxylase blood clotting 500 million

PTS: 1 OBJ: Fill-in-the-Blanks TOP: 25.2 COMPARING BASIC BODY PLANS 2. Choose the most appropriate description for each term. a.

An evolutionary process whereby sensory structures and nerve cells became concentrated in a head b. The back surface c. Animal body cavity lined with a peritoneum--found in most bilateral animals; some worms lack this cavity, other worms have a false cavity d. Leading end e. Animals having body parts arranged regularly around a central axis, like spokes of a bike wheel f. Primary tissue layers that give rise to all adult animal tissues and organs g. Surface opposite the dorsal surface h. Animal lineage in which blastopore becomes the mouth i. Animals having right and left halves that are mirror images of each other j. Series of animal body units that may or may not be similar to one another k. Trailing end l. Animal lineage in which blastopore becomes the anus m. Multicellular organisms with tissues forming organs and organ systems; diploid body cells; heterotrophic; aerobic respiration; sexual reproduction, sometimes asexual; most are motile in some part of the life cycle; and the life cycle shows embryonic development 1. 2.

______ ______

animals ventral surface

1

3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______

ectoderm, endoderm, mesoderm anterior end radial symmetry bilateral symmetry dorsal surface coelom posterior end segmentation cephalization protostomes deuterostomes

ANS: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

M G F D E I B C K J A H L

PTS: 1

OBJ: Matching

TOP: 25.2 COMPARING BASIC BODY PLANS

3. Match each number in the diagram with the appropriate word or phrase in the lettered list.

a. b. c. d. e. f. g. h.

bilateral coelomate ancestry, 3 germ layers protostomes deuterostomes radial ancestry, 2 germ layers true tissues pseudocoel molting coelom lost

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i. j. k.

chordates cnidarians sponges

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. ANS: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

K J D E H B F G A I C

PTS: 1

OBJ: Matching

TOP: 25.2 COMPARING BASIC BODY PLANS

4. Choose the most appropriate answer for each term. a. b. c. d. e. f. g.

Flagellated cells that absorb and move water through a sponge as well as engulf food Reside in a gelatinous substance between inner and outer cell linings An organism whose two cell layers resemble those of a sponge Form the "collars" of collar cells Random chunks of sponge tissue break off and grow into more sponges Protein fibers and glasslike spicules of silica or calcium carbonate Sexually immature form preceding the adult

1. 2. 3. 4. 5. 6. 7.

______ ______ ______ ______ ______ ______ ______

fragmentation larva amoeboid cells sponge skeletal elements Trichoplax microvilli collar cells

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ANS: 1. 2. 3. 4. 5. 6. 7.

E G B F C D A

PTS: 1 OBJ: Matching TOP: 25.4 CNIDARIANS -- SIMPLE TISSUES, NO ORGANS 5. All (1)____________________ are radial animals; they include jellyfishes, sea anemones, corals, and animals such as Hydra. Most of these animals live in the sea and they alone produce (2)____________________, capsules capable of discharging threads that entangle or pierce prey. Cnidarians have two common body plans, the (3)____________________ that looks like a bell or an upside-down saucer, and the (4)____________________ that has a tubelike body with a tentacle-fringed mouth at one end. The saclike cnidarian gut processes food with its (5)____________________, a sheetlike lining with glandular cells that secrete digestive enzymes. A(n) (6)____________________ lines the rest of the body's surfaces. Each of these linings is referred to as a(n) (7)____________________, a tissue with a free surface that faces the environment or some type of fluid inside the body. The nervous system is a(n) (8)____________________, a simple nervous system to control movement and changes in shape. The (9)____________________ is a layer of gelatinous secreted material that lies between the epidermis and gastrodermis. ANS: 1. 2. 3. 4. 5. 6. 7. 8. 9.

cnidarians nematocysts medusa polyp gastrodermis epidermis epithelium nerve net mesoglea

PTS: 1 OBJ: Fill-in-the-Blanks TOP: 25.4 CNIDARIANS -- SIMPLE TISSUES, NO ORGANS 6. Identify each indicated part of the following illustration.

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1. 2. 3. 4. ANS: 1. 2. 3. 4.

feeding polyp reproductive polyp female medusa planula

PTS: 1 OBJ: Labeling TOP: 25.4 CNIDARIANS -- SIMPLE TISSUES, NO ORGANS 7. Choose from the following. Letters can be used more than once and blanks can have more than one letter. a. b. c.

turbellarians flukes tapeworms

1. 2. 3.

______ ______ ______

4.

______

5. 6. 7. 8.

______ ______ ______ ______

Parasitic. Possess a scolex. Ancestral forms probably had a gut but later lost it during their evolution in animal intestines. Water-regulating systems have one or more tiny, branched tubes called protonephridia. Only a few types (including planarians) live in freshwater habitats. Their life cycles have sexual and asexual phases and at least two kinds of hosts. Flame cells, each with a tuft of cilia, drive excess water out to the surroundings. Thrive in predigested food in vertebrate intestines.

5

9. 10. 11. 12.

______ ______ ______ ______

After division, each half regenerates the missing parts. Proglottids are new units of the body that bud just behind the head. Possess a structure equipped with barbs, hooks, or both. Older proglottids store fertilized eggs; they break off and leave the body in feces.

ANS: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

B, C C C A A B A C A C C C

PTS: 1 OBJ: Choice TOP: 25.5 FLATWORMS -- THE SIMPLEST ORGAN SYSTEMS 8. Identify the parts of the animal shown dissected in the accompanying drawings.

6

1. 2. 3. 4. 5. 6. ANS: 1. 2. 3. 4. 5. 6.

branching gut pharynx (protruding) brain nerve cord ovary testis

PTS: 1 OBJ: Labeling TOP: 25.5 FLATWORMS -- THE SIMPLEST ORGAN SYSTEMS 9. Answer the following exercises with reference to the drawings accompanying the exercise.

1. 2.

_______________ _______________

What is the common name (or genus) of the animal dissected? Is the animal parasitic?

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3. 4.

_______________ _______________

Is the animal hermaphroditic? Name the coelom type exhibited by this animal.

ANS: 1. 2. 3. 4.

planarian (genus name = Dugesia) no yes none (acoelomate)

PTS: 1 OBJ: Short Answer TOP: 25.5 FLATWORMS -- THE SIMPLEST ORGAN SYSTEMS 10. The numbered items in the following illustration represent missing information; fill in the corresponding answer blanks to complete the narrative of the life cycle of the beef tapeworm.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

8

ANS: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Larvae intermediate human (small) intestine proglottids organs proglottids feces larval intermediate

PTS: 1 OBJ: Labeling TOP: 25.5 FLATWORMS -- THE SIMPLEST ORGAN SYSTEMS 11. Choose the appropriate answer for each term. a. b. c. d. e. f. g. h. i. j. k. l. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Fluid-cushioned coelomic chambers Oligochaete scavengers with a closed circulatory system and few bristles per segment Paired, each a bundle of extensions of nerve cell bodies leading away from the brain Possess many bristles per segment Aquatic organisms with false coeloms Secreted wrapping around the body surface of most annelids that permits respiratory exchange A rudimentary aggregation of nerve cell bodies that integrate sensory input and muscle responses for the whole body Lack bristles Except for leeches, chitin-reinforced bristles on each side of the body on nearly all segments Segmented worms An enlargement of the nerve cord in each segment of an earthworm Regulate volume and composition of body fluids; often begin with a funnel-shaped structure in each segment ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______ ______

cuticle annelids earthworms marine polychaetes brain nephridia nerve cords setae or chaetae rotifers hydrostatic skeleton leeches ganglion

ANS: 1. 2.

F J

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3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

B D G L C I E A H K

PTS: 1

OBJ: Matching

TOP: 25.7 ROTIFERS

12. Describe how an earthworm burrows into the soil.

ANS: The earthworm uses its hydrostatic skeleton to extend longitudinal muscles in the anterior end while segments in the posterior end have their setae fixed into the wall of the burrow. This pushes the anterior end of the worm forward. Next the worm fixes the anterior setae and releases the posterior setae while shortening its segments. This pulls the posterior end forward. The worm then fixes the posterior setae and repeats the motion. PTS: 1

OBJ: Short Answer

TOP: 25.7 ROTIFERS

13. What is the purpose of the ciliated lobes at the head end of rotifers?

ANS: They aid in moving food into the mouth (and in locomotion). PTS: 1

OBJ: Short Answer

TOP: 25.7 ROTIFERS

14.

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