Download CH 29 Review Answer Key

CH 29 Review Answer Key or….LOOK IN THE BOOK
Reviewing the Chapter
1. List the criteria used to classify animals. (pg 518)
Organization of tissues, symmetry, body plan, type of coelom, segmentation, type of embryonic cells division, and
molecular data.
2. What does the traditional phylogenetic tree (Fig 29.2) tell you about the evolution of the animals studied in this
chapter? (pg 519)
Strongly suggests that life evolved from simpler/less complex organisms into increasing more complex animals in
incremental stages.
3. What features make sponges different from other organisms placed in the animal kingdom? (522-523)
Sponges have only cellular level of organization. They are also the only animals that have digestion occurring in cells.
4. List the type of cells found in a sponge, and describe their functions. (pg 522)
amoebocytes – act as a circulatory device to transport nutrients
choanocytes or collar cells – flagella produces water currents
epidermal cells – outer layer with contractile fibers
5. What are the two body forms found in cnidarians? Explain how they function in the life cycle of various types of
cnidarians? (pg 524)
Medusa and Polyp. NOT ALL CNIDARIANS HAVE BOTH. SOME ARE MORE PROMINENT THAN OTHERS
Medusa is the free-swimming; involved in sexual reproduction
Polyp is the sessile stage; produces medusa via asexual budding
6. Describe the anatomy of the hydra, pointing out those features that typify cnidarians.
(pg 526-527)
Typical cnidarian features: tentacles, nematocysts, 2 body layers
7. Describe the anatomy of a free-living planarian, pointing out those features tat typify
non-parasitic flatworms. (pg 528-529)
Pharynx, excretory system (flame cell), bilateral symmetry
8. Describe the parasitic flatworms, and give the life cycle of both the blood fluke that causes schistosomiasis and the
pork tapeworm. (pg 530)
Flukes (Trematodes) and tapeworms (cestodes) are covered with a protective tegument to resist host digestive juices.
They also lack a high degree of cephalization and nervous system. They do have a well develop reproductive system.
Figure 29.10 Life cycle of a blood fluke, Schistosoma.
Figure 29.10 Life cycle of a pork tapeworm.
9. What is a pseudocoelom? What
are the advantages of a coelom?
What two groups of animals have
a pseudocoelom? (pg 532)
A pseudocoelom is a “false” body
cavity, meaning there is no true
coelom. A true coelom involves a
tube-within-a-tube system that has
mesoderm tissues lining the
endoderm and ectoderm with a space
in between the mesoderm tissue
which holds and maintains position of
internal organs. The advantages is
more space for a circulatory system
which can allow the organism to grow
larger. In CH 29 the only animals with
a pseudocoelom would be the
Nematoda and the Rotifera.
10. Describe the anatomy of
Ascaris, pointing out those
features that typify roundworms.
(pg 533)
Typical roundworm anatomy
involves a pseudocoelom and
bilateral symmetry. Many
roundworms are parasitic so they do
not have a highly developed
digestive system or nervous system.
They do have an extensive
reproductive system to produce
many offspring.
Testing Yourself
(answers only)
1. d 2. e. 3. e. 4. d. 5. b.
10. a – gastrovascular cavity
11. a. Cnidarian and Ctenophora
11. d. Nematoda, Nemertea
12. a tapeworm
b. planarian
6. e. 7. a. 8. c. 9. a.
b. tentacle c. mouth
b. Nematoda, Rotifera
e. Platyhelmithes
c. sponge d. Hydra
d. mesoglea
c. Cnidarian and Ctenophora
f. Cnidaria
e. rotifer
f. planarian g. Hydra
Thinking Scienficially
1. Radially symmetrical animals, that aren’t sessile, generally float about and/or pulse their bodies to
move or drift in the water. Bilaterally symmetrical animals, that are not parasites, free swim in the
direction of their heads. The notable exception to this is the hydra which somersaults along a surface.
2. Having a complete digestive track allows animals to more efficiently process or absorb nutrients
from food. The flatworms (phylum Platyhelminthes) do not have a tube within a tube body plan so
food as to go in, get processed and then out the same opening. This obviously decreases the amount
of time food can be taken into the animal. Roundworms (phylum Nematoda) have the tube-within-atube system so food only moves in one direction which then increases they amount of time food can
be taken in. The more food an organism takes in, the more successful it will be and therefore will
leave more offspring, which is probably why there are more roundworm species.
Understanding the Terms
a. gastrovascular cavity
b. coelom
e. tube-within-a-tube body plan
c. pseudocoelom
d. bilateral symmetry