Animal Characteristics
- Multicellular
- Heterotrophs
- Release energy from food
- Cells need oxygen
- Reproduce (Most reproduce sexually, some reproduce asexually)
Classification
Classified by:
- How it looks
- How it develops
- Content of DNA
Vertebrates - Animals with backbones
Invertebrates - Animals without backbones
- How it looks
- How it develops
- Content of DNA
Vertebrates - Animals with backbones
Invertebrates - Animals without backbones
Animal Symmetry
Bilateral Symmetry - One line that divides an animal into two equal halves. (mirror images)
Radial Symmetry - Animals with many lines of symmetry that all go through a central point.
No Symmetry - Animals that cannot be divided into equal halves by a line of symmetry.
Radial Symmetry - Animals with many lines of symmetry that all go through a central point.
No Symmetry - Animals that cannot be divided into equal halves by a line of symmetry.
Sponges

- Live in water all over world
- Invertebrates
- Generally no body symmetry
- No tissue or organs
- Has many tiny pores
- Reproduces – Asexually (budding) and Sexual (fertilization)
Cnidarians

- Invertebrates
- Stinging cells to capture food and defend
- Radial symmetry
- Tentacles that contain stinging cells
- Reproduces – Asexual and Sexual
- Two types: Medusa and Polyp
- Medusa - Bowl-shaped body plan, Swimming life, Mouths open downward, Tentacles trail down
- Polyp - Vase-shaped body plan, Mouth opens at top, Tentacles spread out from mouth, Attaches to underwater surface
Worms

- Invertebrates
- No legs
- Bilateral symmetry
- Reproduce – asexually and sexually
- Three types: flatworms, roundworms, segmented worms.
Mollusks

- Invertebrates
- Unsegmented bodies
- Bilateral symmetry
- Have an organ called a foot
- Three types: gastropods, bivalves, cephalopods
Arthropods

- Invertebrates
- Exoskeleton – external skeleton
- Molting: when an animal sheds the exoskeleton
- Segmented body
- Bilateral symmetry
- Appendages (used to move)
- Reproduces sexually
- Four Groups: insects, crustaceans, centipedes, and millipedes
Insects (Arthropods)

- Largest group of arthropods
- Three body sections (head, thorax, abdomen)
- Three pairs of legs (six legs)
- One pair of antennae
- One or two pairs of wings
- Complete Metamorphosis (egg, larva, pupa, adult)
- Gradual Metamorphosis (egg, nymph, mini adult, adult)
Crustaceans (Arthropods)

- Watery environments
- Two or three body sections
- Five or more pairs of legs
- Two pairs of antennae
- Gills to obtain oxygen
- Scavengers or predators
Arachnids (Arthropods)

- Two body sections
- Four pairs of legs
- No antennae
- Four types: spiders, ticks, mites, scorpions
- Spiders - Predators, Hollow fangs, Spin webs
- Ticks - Parasites, Sucks blood
- Mites - Parasites, Live all over the world
- Scorpions - Live in hot climates, Active at night, Spine-like stinger
Centipedes & Millipedes (Arthropods)

- Two body sections
- Numerous pairs of legs
- One pair of antennae
- Centipedes (One pair of legs per segment, Predator, inject venom)
- Millipede (Two pairs of legs per segment, More than 80 segments, Scavengers)
Echinoderms (Arthropods)

- Invertebrates
- Endoskeleton – internal skeleton
- Radial symmetry
- Water vascular system
- Reproduction – egg, larvae, metamorphosis
- Major groups: sea stars, brittle stars, sea urchins, sea cucumbers
Fish

- Largest group of vertebrates
- Live in water
- Have fins to help swim
- Ectotherms – Body temperature changes depending on the environment.
- Obtain oxygen through gills
- Have scales
- Reproduce – external fertilization
- Three groups: Jawless, Cartilaginous, Boney
Amphibians

- Salamanders, frogs, and toads
- Begins life in water, spends adulthood on land
- Reproduces – egg, embryo, larvae, metamorphosis.
- Gills as youth to get oxygen, lungs as adult
- Strong skeletons and limbs to move on land
Reptiles

- Vertebrates
- Ectothermic
- Scaly skin
- Lay eggs on land
- Oxygen from lungs
- Carnivores
- Groups: lizards, snakes, alligators, crocodiles, turtles
Birds

- Vertebrates
- Endothermic - Regulates body temp by controlling the internal heat it produces
- Lay eggs
- Have feathers
- Most fly (hollow bones)
- Scales on feet and legs
- Bills - used to capture, grip, and handle food
Mammals

- Vertebrates
- Endothermic
- Skin covered with hair or fur
- Most young born alive
- Four-chamber heart, pair of lungs
- Teeth – chew and tear food
- Three groups: monotremes, marsupials, and placental mammals
- Monotremes - Just three species, two species of anteaters and the duck-billed platypus. Lay eggs, hatch young, and finish developing outside the egg.
- Marsupials - Koalas, kangaroos, opossums. Young born at young age, develop in mother’s pouch
- Placental - Most mammals, including humans. Young develops inside mother’s body until able to function independently