Download Chapter 11: INVERTEBRATES

Chapter 11: INVERTEBRATES
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Chapter 11: INVERTEBRATES
What is an animal?
An organism’s structure:
Study of how an organism functions:
Levels of Organization:
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Functions of Animals
Major functions of Animals:
1. Obtaining food and oxygen
What do animals eat?
How do animals get oxygen?
2. Keeping internal conditions stable
Examples:
3. Moving
Examples:
4.Reproducing (two types)
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Symmetry
A balanced arrangement of body parts that is
characteristic of many animals
Bilateral:
Radial:
No symmetry:
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Symmetry
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Classification of Animals
There are more than 1.5 million identified species
Classifying animals helps biologists make sense of this
diversity
Scientists often correlate strength of relationship
between species with the number of characteristics that
they share
Animals are classified according to similarities in:
body structure
body development
similarity in DNA sequence
35 Phyla: 1 for vertebrates, the rest for invertebrates
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Chapter 15
Invertebrates
Section 1: Simple Invertebrates
Section 2: Mollusks and Annelid Worms
Section 3: Arthropods
Section 4: Echinoderms
End of Slide
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Section 1
Simple Invertebrates
Objectives
• Describe how sponges and cnidarians get food, move
around, and reproduce.
• Explain what a larva is.
• Describe the two body plans of cnidarians.
•.
End of Slide
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Section 1
Simple Invertebrates
Video clip: sponges
End of Slide
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Section 1
Simple Invertebrates
Sponges
• How Do Sponges Eat? Adult sponges stay in one place.
A sponge sweeps water into its body through special cells
called COLLAR cells.
• Reproduction Sexual reproduction: Each sponge
produces BOTH eggs AND sperm!.
Asexual reproduction: parent breaks off a chunk of cells
that becomes another sponge
• Body structure Sponges have no symmetry, no body
organs, no body tissues. They are just a collection of cells
that work together.
End of Slide
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Section 1
Simple Invertebrates
Cnidarians
• Two Body Forms A cnidarian body can have one of two
forms— the medusa or the polyp form.
MEDUSA: bowl shaped, swimming form
POLYP: vase shaped, attached to a surface (non-swimming)
• Stinging Cells All cnidarians have tentacles covered with
stinging cells. They are used for defense and to capture food.
• Eating Catch animal with stinging cells. Use tentacles to pull
prey into mouth. Move prey into gut, where it is digested.
Expel waste through mouth.
End of Slide
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Section 1
Simple Invertebrates
Cnidarians
• Movement Cnidarians have “nerve nets” that signal their
cells to move (beating jellyfish, somersaulting hydra)
•
End of Slide
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Section 1
Simple Invertebrates
Cnidarians
End of Slide
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Section 1
Simple Invertebrates
Budding (Asexual Reproduction)
End of Slide
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Section 1
Simple Invertebrates
Worms
• have long, narrow bodies, and no legs
• 3 kinds: flatworms, round worms, segmented worms
•Phyla: Platyhelminthes, Nematoda, Annelida
•What kind of symmetry?
•They have tissues, organs, and organ systems
End of Slide
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Section 1
Simple Invertebrates
Worms
• Nervous system: simple brain and sense organs
•Reproduction:
•some do asexual reproduction
•Most species can reproduce sexually
•Male and female individuals
•Hermaphrodites
End of Slide
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Section 1
Simple Invertebrates
Flatworms
• Planarians Planarians are free-living. They live in
freshwater lakes and streams. Most planarians are
predators and scavengers. They insert a “feeding tube”
into their prey. They have eyespots.
• Flukes Flukes are parasites. A parasite is an organism
that invades and feeds on the body of a host. Most flukes
live and reproduce inside the bodies of other animals.
• Tapeworms Tapeworms are parasites. They often have
more than one host in their lifetime.
•All flatworms have ONE body opening!
Mouth = anus
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Section 1
Simple Invertebrates
Roundworms
•Roundworms have bodies that are long, slim, and
round, like spaghetti.
•They have a digestive system that is a tube, open at
both ends. (mouth is NOT the anus)
End of Slide
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Section 2
Mollusks and Annelid Worms
Annelid Worms (Segmented worms)
• Earthworms Earthworms are the most common annelid
worms. Each earthworm has 100 to 175 segments.
•Other segmented worms: leeches, sea-floor worms
•Have a one-way digestive system with mouth and
anus
•Well-developed organ system
• Closed circulatory system: blood is held in blood
vessels, can be pumped around the body
End of Slide
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Section 2
Mollusks and Annelid Worms
Mollusks
• Body structure: Soft, unsegmented body. Sometimes
has a shell.
• Mantle: Thin tissue that covers internal organs
• Foot: Muscular organ
• Symmetry: Bilateral
•Digestive system: Two openings (mouth AND anus)
End of Slide
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Section 2
Mollusks and Annelid Worms
Mollusks
• Circulatory system: OPEN! (not like earthworms)
Blood sloshes around the body cavity
• Gills: Allow oxygen from the water to enter the body
• 3 major groups of mollusks: gastropods, bivalves,
cephalopods
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Gastropods
The gastropods are the largest group of mollusks
Have ONE external shell OR NO shell at all
Examples: Snails, slugs
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Ocean gastropods: video
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Bivalves
Have two shells held together by hinges and
strong muscles
Examples: clams, oysters, scallops, mussels
Giant clam: video
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Cephalopods
• Ocean Dwelling
• Foot is adapted to form tentacles around mouth
• Carnivorous
•Examples: Octopuses, cuttlefish, nautiluses, squids
•Camouflage defense: video
End of Slide
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Arthropods
Characteristics of Arthropods
• Segmented and Specialized: Like annelid worms,
arthropods are segmented.
• Jointed Limbs called APPENDAGES: Legs or other
body parts that bend at the joints.
• An External Skeleton: The hard, external structure that
covers the outside of the body is an exoskeleton.
• Major Groups: Crustaceans, arachnids, centipedes and
millipedes, insects
End of Slide
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Arthropods
Kinds of Arthropods
•Other details:
•bilateral symmetry
•Open circulatory system
•Digestive system with TWO openings
•Sexual reproduction
End of Slide
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Arthropods
Exoskeleton
• Waxy: protects the animal, prevents evaporation
• Molting: Process of shedding exoskeleton
End of Slide
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Arthropods
Crustaceans
• 2 or 3 body sections
•5 or more pairs of legs
• 2 pairs of antennae
•Have gills
•Metamorphosis: change from larva form to adult form
End of Slide
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Arthropods
Arachnids
• 2 body sections
•1: head + midsection
•2: abdomen (reproductive organs, some digestive
organs)
•4 or more pairs of legs
• no antennae
End of Slide
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Arthropods
Centipedes, millipedes
• 2 body sections
•Numerous pairs of legs
• Centipedes: one pair of legs per segment
•Millipedes: two pairs of legs per segment
•Video clip
End of Slide
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Arthropods
Insects
• 3 body sections
•1: Head
•2: Thorax – legs and wings attach to this section
• 3: Abdomen – contains internal organs
•6 legs
• Insects go through complete metamorphosis OR
gradual metamorphosis
End of Slide
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Arthropods
Complete Metamorphosis
• Egg  Larva  Pupa (enclosed in case)  Adult
•Example: Butterflies
Gradual Metamorphosis
• Egg  Nymph (looks like a miniature adult)  Adult
•Example: Grasshoppers and cockroaches
End of Slide
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Stages of Complete Metamorphosis
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Stages of Incomplete Metamorphosis
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Section 4
Echinoderms
Bellringer
Echinoderms include marine animals such as sea stars,
sea urchins, and sea cucumbers. All these organisms are
slow moving animals that live on the ocean floor. How do
you think they protect themselves from predators?
Write your response in your science journal.
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Section 4
Echinoderms
Objectives
• Describe the endoskeleton, nervous system, and water
vascular system of echinoderms.
• Explain how an echinoderm’s body symmetry changes
with age.
• Describe five classes of echinoderms.
End of Slide
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Section 4
Echinoderms
Spiny Skinned
• Endoskeleton The name echinoderm means “ spiny
skinned.” An echinoderm’s internal skeleton is called an
endoskeleton.
Bilateral and Radial?
• Adults vs.. Larvae Adult echinoderms have radial
symmetry. But they develop from larvae that have bilateral
symmetry.
End of Slide
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Section 4
Echinoderms
The Nervous System
• Endoskeleton All echinoderms have a simple nervous
system similar to that of a jellyfish. Around the mouth is a
circle of nerve fibers called the nerve ring.
Water Vascular System
• Fluid-Filled Canals The water vascular system is a
system of canals filled with fluid. A water vascular system is
illustrated on the next slide.
End of Slide
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Section 4
A Water Vascular System
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Section 4
Echinoderms
Kinds of Echinoderms
• Brittle Stars and Basket Stars Brittle stars and basket
stars look like sea stars. But these echinoderms have long,
slim arms and are often smaller than sea stars.
• Sea Urchins and Sand Dollars Sea urchins and sand
dollars are round. Their endoskeletons form a solid, shelllike structure.
End of Slide
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Section 4
Echinoderms
Kinds of Echinoderms continued
• Sea Lilies and Feather Stars Sea lilies and feather stars
have 5 to 200 feathery arms.
• Sea Cucumbers Like sea urchins and sand dollars, sea
cucumbers have no arms. A sea cucumber has a soft,
leathery body.
End of Slide
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Chapter 15
Invertebrates
Concept Map
Use the following terms to complete the concept map on
the next slide: cnidarians, symmetry, invertebrates,
mollusks, annelid worms, snails, bilateral, sponges, coral,
asymmetry.
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Chapter 15
Concept Map
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Chapter 15
Concept Map
Copyright © by Holt, Rinehart and Winston. All rights reserved.