Animal Diversity

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Animal Diversity
Exploring the Categorization of Animal Species
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The Tree of Life The three domains of life
represent the earliest branches in evolutionary
history
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Characteristics of Animals

• Eukaryotic
• Multicellular
• Heterotrophic
• Most are capable of sexual reproduction.
• Animal cells lack a cell wall.
• Motile during some stage of their life
• Respond to external stimuli as a result of nerve
  and/or muscle action

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Classification Scheme
Kingdom
Animalia
Animalia
Phylum
Chordata
Chordata
Mammalia
Mammalia
Class
Primates
Carnivora
Order
Felidae
Family
Hominidae
Homo
Felis
Genus
sapiens
Species
sylvestris
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Ways to DistinguishBetween Animal Groups
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Body symmetry
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Phylum PoriferaSponges

• Asymmetrical
• Loosely structured collection of cells
• Cell specialization
• Lack tissues
• Non-motile as adults
• Filter feeders

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Phylum CnidariaCoral, Hydra, Anemones and
Jellyfish

• Radial symmetry
• Cells organized into two tissue layers
• Lack true organs
• Nerve network and contractile tissue
• Body plans Polyp- attached Medusa- motile
• Mouth and anus are same opening
• Asexual and sexual reproduction

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Body Cavities
Coelom body cavity lined on all sides
by a layer of mesodermal cells
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Phylum PlatyhelminthesTapeworms, Flukes ,
Flatworms

• Bilateral symmetry
• Acoelomate
• Three tissue layers
• Excretory and Reproductive Organs
• Move by use of nerve cells, ganglia
• Many are free-living
• some are parasitic

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Phylum NematodaRoundworms

• Bilateral symmetry
• Pseudocoelomate
• Three tissue layers
• Tubular gastrovascular cavity two openings
• Ganglionic Brain
• Gas exchange by diffusion
• A few species are parasitic

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Phylum Annelida Segmented Worms

• Bilateral symmetry
• Coelomate, fluid filled cavity allows movement
• Three tissue layers
• Segmented body
• Closed circulatory system 5 pairs of hearts
• Excretory organs nephridia
• Digestive system with specialized areas
• Segmented muscles for movement

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Phylum Mollusca

• Bilateral symmetry
• Coelomate
• Three tissue layers
• Soft body in a calcium containing shell
• 3-chambered heart, blood vessels
• Ciliated digestive tract
• Excretory organs nephridia
• Head-foot has sensory and motor organs
• Gills for oxygen absorption
• Tooth-bearing strap radula

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Classes of Phylum Mollusca

• Class Bivalvia
• clams, mussels, oysters, scallops
• Class Gastropoda
• snails, slugs
• Class Cephalopoda
• squid, octopus
• Class Polyplacophora
• chitons (ancestral)
• eight plates on back

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Phylum Arthropoda

• Bilateral symmetry
• Coelomate
• Three tissue layers
• Distinct body regions head, thorax, abdomen
• joint-footed
• Exoskeleton, moved at joints by muscles
• Open circulatory system
• Complex nervous system, compound eye
• Efficient gas exchange system

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Classes of Phylum Arthropoda

• Class Arachnida
• spiders, ticks, scorpions
• Class Crustacea
• crabs, lobsters, shrimp
• Class Insecta
• insects
• Class Diplopoda
• millipedes2 pairs of legs/segment
• Class Chilopoda
• centipedes1 pair of legs/segment
• Class Meristomata
• horseshoe crabs

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Protostome mouth forms first during embryonic
development Deuterostome anus forms first
and then mouth forms
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Phylum Echinodermata

• Radial symmetry, 5-part body plan
• Coelomate
• Deuterostome
• Three tissue layers
• Spiny Skin
• Modified coelom forms a water vascular system to
  move tube feet
• Nervous system central nerve ring with branches

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Classes of Phylum Echinodermata

• Class Asteroidea
• sea stars
• Class Echinoidea
• sea urchins, sand dollars
• Class Holothuroidea
• sea cucumbers
• Class Ophiuroidea
• brittle stars

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Phylum Chordata

• Bilateral symmetry
• Coelomate
• Deuterostome
• Three tissue layers
• Four common features
• Notochord
• Dorsal, hollow nerve cord
• Pharyngeal gill slits
• Post-anal tail

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Sub-Phylum Vertebrata

• Notochord replaced by vertebral column
• Endoskeleton
• Development of brain
• Closed circulatory system,heart with 2 or more
  chambers
• Use of gills, skin or lungs to obtain oxygen
• waste removal by kidneys
• Separate sexes, internal or external fertilization

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Classes of Sub-Phylum Vertebrata

• Class Agnatha
• jawless fishes
• Class Condrichhthyes
• cartilaginous fish
• Class Osteichthyes
• bony fish

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Classes of Sub-Phylum Vertebrata

• Class Amphibia
• frogs, toads, salamanders
• Class Aves
• birds
• Class Reptilia
• lizards, snakes, turtles, alligators

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Classes of Sub-Phylum Vertebrata

• Class Mammalia
• most bear live young
• milk from mammary glands
• hair
• endotherms
• monotremes egg laying
• platypus
• marsupials
• kangaroo
• placentals
• bat, rabbit, dog, cattle, whale, human

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Worksheet

• Complete pages 125-126 from lab manual
• Record your answer and reasoning for any 8
  specimens, making sure to write the answer on the
  line that matches the specimen number
• Be sure your instructor checks your completed
  worksheet before you leave the lab.

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CLEAN UP!

• Leave animal specimens and their skeletons in
  orderly arrays
• Thank you!