SimpleVetebrates(Ch.16)
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Transcript SimpleVetebrates(Ch.16)
Chapter 16
Fishes, Amphibians, and
Reptiles
Table of Contents
Section 1 Fishes: The First Vertebrates
Section 2 Amphibians
Section 3 Reptiles
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Bellringer
What are some of the physical characteristics shared
by dinosaurs and people?
Write your response in your science journal.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Objectives
• List the four common body parts of chordates.
• Describe the two main characteristics of vertebrates.
• Explain the difference between an ectotherm and an
endotherm.
• Describe four traits that fishes share.
• Describe the three classes of living fishes, and give
an example of each.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Chordates
• * are called vertebrates.
• Vertebrates belong to the phylum chordata.
• While vertebrates make up the largest group of
chordates, some chordates, such as lancelets and
tunicates, do not have a backbone.
• The four particular body parts shared by chordates
are illustrated on the next slide.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Vertebrate Characteristics
• Fishes, amphibians, reptiles, birds, and mammals
are vertebrates.
• * called vertebrae.
• Vertebrates have a well-developed head protected
by a skull. The skull can be made of either bone or
cartilage.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Are Vertebrates Warm or Cold?
• All vertebrates need to live at the proper
temperature. Animals have different ways to keep
their body at the right temperature.
• Staying Warm An Endotherm is an animal that *
• Birds and mammals are endotherms. These
animals are sometimes called warmblooded.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Are Vertebrates Warm or Cold? continued
• Cold Blood? An ectotherm is an organism that
needs sources of heat outside of itself. Their body
temperature changes as the temperature of the
environment changes.
• Nearly all amphibians, reptiles, and fishes are
ectotherms. These animals are sometimes called
coldblooded.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Fish Characteristics, continued
• Making Sense of the World Fishes have a brain
that keeps track of information coming in from the
senses.
• Most fishes also have a lateral line system. The
lateral line is a row or rows of tiny sense organs on
the side of fishes that detect water vibration.
• Underwater Breathing Fishes use their gills to
breathe. A gill is *
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Fish Characteristics
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Fish Characteristics, continued
• Making More Fishes Most fishes reproduce by
external reproduction. *
• Some species of fishes have internal fertilization.
The male deposits sperm inside the female.
• Most females then lay eggs with embryos inside of
them. In some species, the embryos develop inside
the female.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Kinds of Fishes
• There are five different classes of fishes. Two of
these classes are now extinct.
• The three classes of fishes that are still alive today
are *
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Kinds of Fishes, continued
• Jawless Fishes The two kinds of modern jawless
fishes are *
• Hagfish and lampreys are eel-like. They have
smooth slimy skin and a round, jawless mouth.
• Jawless fish have a *
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Kinds of Fishes, continued
• Cartilaginous Fishes In most vertebrates, soft
cartilage in the embryo is slowly replaced by bone.
But in sharks, skates, and rays, the skeleton never
changes to bone. So, they are called cartilaginous
fishes.
• Cartilaginous fishes have fully functional jaws.
• Cartilaginous fishes store a lot of oil in their livers to
help them float.
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Chapter 16
Section 1 Fishes: The First
Vertebrates
Kinds of Fishes, continued
• Bony Fishes The largest class of fishes is the bony
fishes. These fishes have a skeleton made of bone
and a body made of bony scales.
• Bony fishes have a swim bladder. A swim bladder
is *
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Section 1 Fishes: The First
Vertebrates
Kinds of Fishes, continued
• There are two groups of bony fishes. Ray-finned
fishes have pairs of fins supported by thin rays of
bone.
• Lobe-finned fishes have fins that are muscular and
thick.
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Chapter 16
Section 2 Amphibians
Bellringer
Name an advantage and a disadvantage of the thin,
moist skin of amphibians.
Write your answers in your science journal.
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Chapter 16
Section 2 Amphibians
Objectives
• Explain how amphibians breathe.
• Describe amphibian metamorphosis.
• Describe the three groups of amphibians, and give
an example of each.
• Explain why amphibians are ecological indicators.
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Chapter 16
Section 2 Amphibians
Moving to Land
• Amphibians are animals that can live in water and
have lungs and legs.
• A lung is a *
• Most of today’s amphibians are frogs or salamanders.
• Fossils have been found of amphibians that looked
very different––like a cross between a fish and
salamander and up to 10 m long.
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Chapter 16
Section 2 Amphibians
Characteristics of Amphibians
• Amphibian means”double life.” Most amphibians live
part of their lives in water and part of their lives on
land.
• Embryos must develop in water. The eggs do not
have a shell or membrane that prevents water loss, so
the eggs would dry up on land. Adults can live on land.
• Amphibians are *
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Chapter 16
Section 2 Amphibians
Characteristics of Amphibians, continued
• Thin Skin Amphibian skin is thin, smooth, and moist.
The skin is so thin that amphibians *
• Amphibians can also lose water through their skin
and become dehydrated. Their thin skin is one reason
amphibians live in water or damp habitats.
• Amphibians can breathe by gulping air. Many also
absorb oxygen through their skin.
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Section 2 Amphibians
Characteristics of Amphibians, continued
• Leading a Double Life Most amphibians change
form as they grow.
• A tadpole *
• As a tadpole grows, it develops limbs and lungs and
loses its tail and gills.
• This change from an immature form to an adult form
is called metamorphosis.
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Chapter 16
Section 2 Amphibians
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Section 2 Amphibians
Kinds of Amphibians
• Caecilians Caecilians live in tropical areas of Asia,
Africa, and South America. They look like earthworms
or snakes, but they have the thin, moist skin of
amphibians.
• Salamanders As adults, most salamanders live
under stones and logs in the woods of North America.
They have long tails and four strong legs.
• Salamanders do not develop as tadpoles. But most
do lose gills and grow lungs during development.
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Chapter 16
Section 2 Amphibians
Kinds of Amphibians, continued
• Frogs and Toads About 90% of all amphibians are
frogs or toads. They live all over the world, except in
very cold places.
• Frogs and Toads are highly adapted for life on land.
Adults have strong leg muscles for jumping
• They have well-developed *.
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Section 2 Amphibians
Kinds of Amphibians, continued
• Singing Frogs Frogs force air from their lungs over
their vocal cords to make sound.
• A thin-walled sac of skin called the vocal sac
surrounds the vocal cords and increases the volume of
the songs.
• Frogs sing songs to communicate messages about
attracting mates and marking territories.
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Chapter 16
Section 2 Amphibians
Amphibians as Ecological Indicators
• Unhealthy amphibians can be an early sign of
changes in an environment.
• Amphibians are ecological indicators because they
are very sensitive to changes in the environment. Their
thin skin absorbs any chemicals in the water or air.
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Chapter 16
Section 3 Reptiles
Bellringer
List three adjectives you associate with reptiles
Record your list in in your science journal.
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Chapter 16
Section 3 Reptiles
Objectives
• Explain the characteristics that allow reptiles to live
on land.
• Describe the characteristics of an amniotic egg.
• Name the four groups of modern reptiles, and give an
example of each.
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Chapter 16
Section 3 Reptiles
Living on the Land
• Reptiles have many characteristics that make them
well suited for life on land.
• Many reptiles are now extinct. Extinct species include
dinosaurs, reptiles that could swim, others that could
swim, and many that were similar to reptiles that are
alive today.
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Section 3 Reptiles
Characteristics of Reptiles
• Reptiles are well adapted for life on land.
• Thick Skin Reptiles have thick skin that forms a
watertight layer that keeps cells from losing water.
• Body Temperature Nearly all reptiles are
ectotherms. They are active when it is warm outside,
and they slow down when it is cool. They do not live in
very cold environments.
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Section 3 Reptiles
Characteristics of Reptiles, continued
• The Amazing Amniotic Egg * an amniotic egg.
Reptiles, birds, and mammals have amniotic eggs.
• Reptiles eggs also have a shell. The shell *
• A reptile’s eggs can be laid under rocks, in the
ground, or even in the desert.
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Section 3 Reptiles
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Section 3 Reptiles
Kinds of Reptiles
• Turtles and Tortoises Generally, tortoises live on
land, and turtles spend all or much of their lives in the
water. However, even sea turtles come on land to lay
their eggs.
• The trait that makes turtles and tortoises so unique is
their shell. The shell gives them *
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Section 3 Reptiles
Kinds of Reptiles, continued
• Crocodiles and Alligators Crocodiles and alligators
spend most of their time in the water. Because their
eyes and nostrils are on the top of their flat heads, they
can hide with most of their body under water.
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Section 3 Reptiles
Kinds of Reptiles, continued
• Snakes and Lizards Today, the most common
reptiles are snakes and lizards.
• Snakes have many adaptations for hunting. They can
“taste” if their prey is nearby.
• Some snakes have venomous fangs for killing prey.
Other snakes squeeze their prey until they suffocate it.
• Snakes swallow their prey whole.
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Section 3 Reptiles
Kinds of Reptiles, continued
• Most lizards eat small insect and worms, but some
lizards eat plants.
• Many lizards can break their tails off to escape
predators and then regrow new tails.
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Section 3 Reptiles
Kinds of Reptiles, continued
• Tuataras Tuataras live on only a few islands off the
coast of New Zealand.
• Although they look similar to lizards, the two reptiles
have some obvious differences. Tuataras do not have
visible ear openings.
• Unlike other reptiles, tuataras are most active when
the temperature is low.
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