Interest Grabber

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Interest Grabber
Section 26-1

• Whats the Difference?
• In the course of the day, you probably have
  encountered animalsand other types of organisms.

1. Make a list of five animals that you saw
today. 2. Then, make a list of five organisms
other than animals that you saw today. 3. What
characteristics do animals have that the other
types of organisms do not?
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Section Outline
Section 26-1

• 261 Introduction to the Animal Kingdom
• A. What Is an Animal?
• B. What Animals Do to Survive
• 1. Feeding
• 2. Respiration
• 3. Circulation
• 4. Excretion
• 5. Response
• 6. Movement
• 7. Reproduction
• C. Trends in Animal Evolution
• 1. Cell Specialization and Levels of Organization
• 2. Early Development
• 3. Body Symmetry
• 4. Cephalization
• 5. Body Cavity Formation

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Concept Map
Section 26-1
Animals
have
are
carry out
with
such as
No cell walls
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Figure 265 Body Symmetry
Section 26-1
Bilateral Symmetry
Radial Symmetry
Posterior end
Dorsal side
Anterior end
Ventral side
Plane ofsymmetry
Planes ofsymmetry
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Interest Grabber
Section 26-2

• No Sinking or Swimming
• You likely have a green, yellow, blue, or pink
  sponge in your kitchen sink at home. This is a
  synthetic (human-made) sponge, not a natural
  sponge. But you may have used a natural sponge in
  the bath or when washing the car. These sponges
  are usually brownish and are irregularly shaped.

1. Natural sponges live in the water, and are
attached to a single spot. Although they cannot
move from place to place like many other animals,
sponges are still animals. Because they are
animals, what characteristics must sponges
have? 2. What characteristics does a kitchen
sponge have? Which of these characteristics do
you think a natural sponge has?
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Section Outline
Section 26-2

• 262 Sponges
• A. What Is a Sponge?
• B. Form and Function in Sponges
• 1. Body Plan
• 2. Feeding
• 3. Respiration, Circulation, and Excretion
• 4. Response
• 5. Reproduction
• C. Ecology of Sponges

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Sponge Life Cycle
Section 26-2
MEIOSIS
Sperm from a sponge are released into the
surrounding water. Water currents carry the sperm
to other sponges.
Haploid (N) Diploid (2N)
New sponge
Sperm (N)
Mature sponge (2N)
Egg (N)
Swimming larva
Larva (2N)
The zygote develops into a free-swimming larva.
Water currents carry the larva until it attaches
to a surface and grows into a new sponge.
Sperm enter another sponge through pores. The
sperm are carried to eggs inside the body wall.
Sperm fertilize eggs.
FERTILIZATION
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Figure 268 The Anatomy of a Sponge
Section 26-2
Water flow
Osculum
Choanocyte
Central cavity
Pores
Spicule
Pore cell
Pore
Epidermal cell
Archaeocyte
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Interest Grabber
Section 26-3

• Whats in a Name?
• Perhaps you have heard about creatures called
  jellyfishes on television,in school, or at an
  aquarium maybe you live near the ocean and have
  actually seen jellyfishes.

1. Do jellyfishes look like what their name
describes? Make a simple drawing of what you
think a jellyfish looks like. 2. Some scientists
suggest that jellyfishes should be called
jellies. What might this new name tell you
about jellyfishes?
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Section Outline
Section 26-3

• 263 Cnidarians
• A. What Is a Cnidarian?
• B. Form and Function in Cnidarians
• 1. Body Plan
• 2. Feeding
• 3. Respiration, Circulation, and Excretion
• 4. Response
• 5. Movement
• 6. Reproduction
• C. Groups of Cnidarians
• 1. Jellyfishes
• 2. Hydras and Their Relatives
• 3. Sea Anemones and Corals
• D. Ecology of Corals

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Jellyfish Life Cycle
Section 26-3
Female medusa(2N)
MEIOSIS
Fertilization occurs in the open water, producing
many diploid zygotes.
Egg (N)
FERTILIZATION
Adult medusas reproduce sexually by releasing
gametes intothe water.
Sperm (N)
Each zygote grows into a ciliated larva. The
larva eventually attaches to a hard surface and
develops into a polyp.
Zygote (2N)
Male medusa(2N)
Youngmedusa
Swimming larva
Polyp
The polypbuds to release young medusas.
Buddingpolyp
Haploid Diploid
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Figure 2612 The Polyp and Medusa Stages
Section 26-3
Epidermis Mesoglea Gastroderm
Medusa
Polyp
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Video Contents
Videos

• Click a hyperlink to choose a video.
• Spineless, Part 1
• Spineless, Part 2

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Video 1
Video 1
Spineless, Part 1

• Click the image to play the video segment.

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Video 2
Video 2
Spineless, Part 2
Click the image to play the video segment.
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Internet
Go Online

• The latest discoveries in insects and
  invertebrates
• Links from the authors on sunscreen from the sea
• Share hydra lab data
• Interactive test
• For links on classifying animals, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-8261.

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Section 1 Answers
Interest Grabber Answers
1. Make a list of five animals that you saw
today. Examples include humans, dogs,
grasshoppers, birds, squirrels. 2. Then, make a
list of five organisms other than animals that
you saw today. Examples include trees, grass,
mushrooms, shrubs, moss. 3. What characteristics
do animals have that the other types of
organisms do not? Animals cannot make their own
food, while plants can. Animals generally can
move from place to place while plants and fungi
cannot.
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Section 2 Answers
Interest Grabber Answers
1. Natural sponges live in the water, and are
attached to a single spot. Although they cannot
move from place to place like many other animals,
sponges are still animals. Because they are
animals, what characteristics must sponges
have? All animals are heterotrophic
multicellular eukaryotic organisms whose cells
lack cell walls. 2. What characteristics does a
kitchen sponge have? Which of these
characteristics do you think a natural sponge
has? A kitchen sponge is full of holes, which
make a network of spaces that hold water.
Students may say that natural sponges also are
full of holes. Students may not be aware that a
natural sponge is hollow, while a kitchen sponge
is not.
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Section 3 Answers
Interest Grabber Answers
1. Do jellyfishes look like what their name
describes? Make a simple drawing of what you
think a jellyfish looks like. Students should
draw sac-like animals with tentacles. 2. Some
scientists suggest that jellyfishes should be
called jellies. What might this new name tell
you about jellyfishes? This new name suggests
that these animals have jelly-like bodies, but
they are not fish.
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End of Custom Shows

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