Interest Grabber

1
Interest Grabber
Section 30-1

• Means of Support
• Imagine that you are on a camping trip. You
  arrive at your campsite and the first thing you
  do is put up your tent.

1. What purpose do the tent poles serve? 2.
How would moving around and sleeping in the tent
be affected if you had forgotten the tent poles
at home? 3. What types of animals have a means
of support that functions like tent poles? Why
would such a means of support be beneficial to
these animals?
2
Section Outline
Section 30-1
301 The Chordates A. What Is a Chordate? B. Most
Chordates Are Vertebrates C. Nonvertebrate
Chordates 1. Tunicates 2. Lancelets
3
Chordate Cladogram
Section 30-1
Mammals
Birds
Reptiles
Amphibians
Fishes
Nonvertebratechordates
Invertebrate ancestor
4
Figure 301 The Generalized Structure of a
Chordate
Section 30-1
5
Interest Grabber
Section 30-2

• A Fishy Picture
• On a sheet of paper, draw a large diagram of a
  fish that is familiar to you. Provide as much
  detail as you can, and label as many parts as
  possible.
• Some of the functions of fishes are as follows
  locomotion, respiration, feeding, protection,
  response, and waste removal. Next to each
  structure label on your drawing, write the
  associated function in parentheses. How is each
  structure related to its function?

6
Section Outline
Section 30-2

• 302 Fishes
• A. What Is a Fish?
• B. Evolution of Fishes
• 1. The First Fishes
• 2. The Age of Fishes
• 3. The Arrival of Jaws and Paired Fins
• 4. The Rise of Modern Fishes
• C. Form and Function in Fishes
• 1. Feeding
• 2. Respiration
• 3. Circulation
• 4. Excretion
• 5. Response
• 6. Movement
• 7. Reproduction

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Section Outline continued
Section 30-2

• D. Groups of Fishes
• 1. Jawless Fishes
• 2. Sharks and Their Relatives
• 3. Bony Fishes
• E. Ecology of Fishes

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Circulation in a Fish
Section 30-2
Gills
Brain and head circulation
Atrium
Sinus Venosus
Oxygen-poor bloodfrom the veins collects in the
sinusvenosus.
Blood enters theatrium and flowsto the
ventricle.
Body muscle circulation
Ventricle
Digestive system circulation
Bulbus Arteriosus
The ventricle pumps blood into the bulbus
arteriosus.
Heart
The bulbus arteriosus moves blood into the
ventral aorta and toward the gills.
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Figure 3011 The Anatomy of a Fish
Section 30-2
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Interest Grabber
Section 30-3

• Declining Numbers of Frogs
• Ecologists have recently noticed declining
  numbers of certain types of amphibians in a
  variety of places. Some scientists have
  hypothesized that this decline might be a result
  of toxins in the environment.
• Work with a partner to discuss and answer the
  questions that follow.

1. What characteristics of amphibians might make
them more susceptible to environmental toxins
than other types of animals? 2. Frogs reproduce
in water. Why might toxins in aquatic ecosystems
affect the reproductive success of frogs? 3. Can
you think of any other possible explanations for
the reduced numbers of amphibians observed?
11
Section Outline
Section 30-3

• 303 Amphibians
• A. What Is an Amphibian?
• B. Evolution of Amphibians
• C. Form and Function of Amphibians
• 1. Feeding
• 2. Respiration
• 3. Circulation
• 4. Excretion
• 5. Reproduction
• 6. Movement
• 7. Response
• D. Groups of Amphibians
• 1. Salamanders
• 2. Frogs and Toads
• 3. Caecilians
• E. Ecology of Amphibians

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Concept Map
Section 30-3
Amphibians
means
Double life
as
larvæ they live in
adults they live on
and have special adaptations such as
are
that allow for
that provide
that allow
are
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Figure 3026 The Life Cycle of a Frog
Section 30-3
Adult Frog
Adults are typically ready tobreed in about one
to two years.
Young Frog
Frog eggs are laid in water and undergo external
fertilization.
The eggs hatch into tadpoles a few days to
several weeks later.
Fertilized Eggs
Tadpoles
Tadpoles gradually grow limbs, lose their tails
and gills, and become meat-eaters as they develop
into terrestrial adults.
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Video
Video
Frog Anatomy

• Click the image to play the video segment.

15
Internet
Go Online

• The latest discoveries in declining amphibian
  populations
• Interactive test
• Articles on chordates and vertebrates
• For links on nonvertebrate chordates, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-9301.
• For links on fishes, go to www.SciLinks.org and
  enter the Web Code as follows cbn-9302.

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Section 1 Answers
Interest Grabber Answers
1. What purpose do the tent poles serve?
Poles provide support and hold up the fabric of
the tent to create an open space inside. 2. How
would moving around and sleeping in the tent be
affected if you had forgotten the tent poles at
home? The fabric of the tent would collapse and
hang down onto people in the tent. There wouldnt
be an open space in which to move around inside
the tent. 3. What types of animals have a means
of support that functions like tent poles? Why
would such a means of support be beneficial to
these animals? Vertebrates. A skeleton provides
support and creates a space inside for internal
organs and the like.
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Section 2 Answers
Interest Grabber Answers

• On a sheet of paper, draw a large diagram of a
  fish that is familiar to you. Provide as much
  detail as you can, and label as many parts as
  possible.
• Some of the functions of fishes are as follows
  locomotion, respiration, feeding, protection,
  response, and waste removal. Next to each
  structure label on your drawing, write the
  associated function in parentheses. How is each
  structure related to its function?
• Students should draw a fish with some or all of
  the following structures labeled fins
  (locomotion) gills (respiration) scales
  (protection, locomotion) mouth (feeding) eyes
  (response) anus (waste removal)

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Section 3 Answers
Interest Grabber Answers
1. What characteristics of amphibians might make
them more susceptible to environmental toxins
than other types of animals? Amphibians live
both in water and on land, have moist skins that
allow the exchange of substances, and do not have
protective scales or a thick impermeable
skin. 2. Frogs reproduce in water. Why might
toxins in aquatic ecosystems affect the
reproductive success of frogs? Eggs and tadpoles
may be more sensitive to toxins in the water
during these developmental stages. 3. Can you
think of any other possible explanations for the
reduced numbers of amphibians observed? Possible
answers more predators presence of a viral,
bacterial, or fungal infection decreasing food
supply and normal fluctuations in population
size.
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End of Custom Shows

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