1. Introduction to Animals

2. What is an Animal? Animal Characteristics Cannot make their own food
Digest their food (food has to be broken down in order for their bodies to use the proteins, fats, and carbohydrates
Many move
Multicellular
Eukaryotic (have a nucleus)

3. Classification of Animals
Scientists have divided the Animal Kingdom into two main groups:
vertebrates (animals with a backbone)
and
invertebrates (animals without a backbone)

4. The Animal Kingdom
The animal kingdom is broken down into 9 major phyla…
1) Sponge
2) Cnidarian
3) Flatworm
4) Roundworm
5) Echinoderm
6) Mollusk
7) Annelid
8) Arthropod
9) Chordate

5. Vertebrates
To classify animals scientists first see if the animal has a backbone. Animals with a backbone are called vertebrates. Some vertebrate animals are:
fish
humans
birds
snakes
elephants
mice

6. Animals with a backbone.
Vertebrates
Animals with a backbone.

7. Invertebrates
About 97% of all animal species are invertebrates- they don’t have backbones. Some examples of invertebrate animals are:
sponges
insects
clams
squid
jellyfish
spiders
worms

8. Animals with backbones can be divided into five more groups:
Vertebrates
Animals with backbones can be divided into five more groups:
Mammals
Birds
Reptiles
Amphibians
Fish

9. Symmetry- Radial
Once scientists have determined whether an animal has a backbone they will look to see if the animal’s body has symmetry.
Any cut through the center of an organism with radial symmetry (dorsal to ventral) results in roughly equal halves in terms of organs and body parts.

10. What has radial symmetry?
Only cnidarians and ctenophores have true radial symmetry.
(What the heck is a ctenophore? It’s similar to a jellyfish. They are commonly known as comb jellies.)

11. Partial Radial Symmetry
Echinoderms like this brittle star
have partial radial symmetry.

12. Bilateral Symmetry
Most animals have bilateral symmetry. An animal with bilateral symmetry has its body parts arranged in the same way on both sides of its body. Bilateral animals can be divided into right and left halves by drawing an imaginary line down the length of its body.

13. What has bilateral symmetry?

14. Asymmetry
Some organisms have no definite shape and are said to be asymmetrical. There is no way their bodies can be divided into matching halves.

15. Skeletal Systems
Exoskeleton
Endoskeleton

16. Exoskeleton-Invertebrates
external skeleton
Arthropods and Mollusks
Arthropod’s skeleton is made of a material called chitin and must be shed to permit growth.
Mollusk’s skeleton is made by the mantle from calcium carbonate.

17. Endoskeleton- Vertebrates
Internal skeleton
Grows with the organism
Made of cartilage or a combination of cartilage and bone.