Unit 14 - Animals

Animal Traits Eukaryotes (complex cells with nuclei) Heterotrophs (do not make their own food) Multicellular Motile (can move) Sexual Reproduction No cell walls

Radial Symmetry Limbs “radiate” out from center point Difficult to move in one direction No eyes or complex organs

Bilateral Symmetry Two symmetrical sides Eyes facing forward Moves easily in one direction

Body Shape Bell (ex: Jellyfish) Tube (ex: Sea anemone) A. Ectoderm B. Tentacles C. Endoderm D. Coelom

Body Support TypeConstructionExample EndoskeletonBoneVertebrates HydrostaticWater pressureEarthworm ExoskeletonChitinInsects ShellCalcium carbonateMollusks

Animal Groups – Invertebrates Invertebrate Phyla: 1.Porifera 2.Cnidarians 3.Platyhelminthes 4.Nematodes 5.Mollusks 6.Annelids 7.Arthropods 8.Echinoderms Invertebrates:  Animals with NO backbone  Make up 97% of animal species  Most live in water

Animal Groups – Vertebrates Vertebrate Phyla: 9. Chordates – the only group of vertebrates! Vertebrates:  Animals with a backbone  Make up 3% of animal species

1. Porifera Ex. Sponges Simplest animals Filter feeders

2. Cnidarians Ex. Jellyfish and coral Stinging cells Radial symmetry

3. Platyhelminthes Ex. Flukes and tapeworms Flatworms First animals with Bilateral symmetry

4. Nematodes Roundworms Hookworms

5. Mollusks Ex. Snails, Octopus, Clams Usually shelled Move with pseudopods

6. Annelids Ex. Earthworms Segmented worms

7. Arthropods: Largest invertebrate group! Insects 6 legs 3 body segments Head, Thorax, Abdomen Antennae and Wings Metamorphosis: change forms over life cycle Arachnids Ex. Spiders, crustaceans (crabs, lobster) 8 legs 2 body segments

8. Echinoderms Ex. Starfish Endoskeleton Closest relative to vertebrates Spiny

9. Chordates Ex. Birds, fish, mammals Vertebrates Have a spinal cord 3% of all animals

Evolutionary Developments- simplest to most complex 1. Multicellular 2. Tissues 3. Body Cavity 4. Coelom (hollow cavity containing internal organs) 5. Bilateral symmetry 6. Segmentation 7. Jointed Appendages (limbs) 8. Complex embryos 9. Spinal Cord

Vertebrate Characteristics 1. Backbone 2. Bilateral symmetry 3. 4 limbs 4. Well developed senses 5. Large brains

Evolution of Vertebrates

Fish Types: 1. Jawless is most primitive 2. Cartilaginous Flexible skeleton 3. Bony Fish (most fish) Scales Gills Lays soft eggs Live only in water Exothermic – don’t produce body heat Swim bladders to help buoyancy

Amphibians Spends half of life in water and half on land First vertebrate group on land Ex. Frogs, newts Exothermic Breathe through their skin - only adults have lungs

Reptiles First to be completely on land Tough, watertight scales Lungs Leathery eggs Exothermic

Birds Lungs Hard eggs Feathers = Modified scales Endothermic – produces own body heat Hollow bones adapted for flight

Mammals Feed young with milk Give birth to live young (not eggs) Hair or fur Endothermic

Types of Mammals Placental Young develop inside mother Ex: Dolphin, human, dog Marsupial Young develop inside mother’s pouch All found in Australia Ex: Kangaroo

Monotremes Mammals that LAY EGGS Ex: platypus Although one of the main traits of a mammal is young that develop inside the mother, monotremes are considered mammals because they have mammary glands and fur. Laying eggs evolved later.