1. I. Classifying Living Things A. Classify: to arrange into groups. B. Scientists classify animals by structure. 1. Scientists look for backbones. 2. Backbones are called vertebrae. C. Animals without backbones are called invertebrates. D. Animals with backbones are vertebrates.

2. II. Sponges A. Most live in oceans. B. Made of many cells C. Adult sponges stay in one place. D. Body has pores, or tiny hole E. Sponges have 3 types of cells. 1. skeletal: provide structure and support. 2. thread-like: push water. 3. digestive: break down food and turn it into energy.

3. F. Grow in different shapes, colors, and sizes 1. cups 2. vases 3. fans

4. III. Animals with stinging cells A. Live in water 1. hydra: fresh water 2. Jelly fish and sea anemones: oceans B. Body has a hollow sac with one opening and surrounded by tentacles. 1. tentacles: long, arm-like parts 2. have many tentacles

5. C. More advanced than sponges because they have stinging cells that paralyze prey. 1. capture prey with tentacles. 2. stinging cells on tentacles paralyze or kill prey. 3. tentacles push prey into hollow sac to be digested. D. Portuguese-Man-Of-War is dangerous to humans. 1. can get tangled in large tentacles 2. stinging cells can cause severe pain

6. IV.Worms A. Flat worms 1. Some live in streams or ponds. 2. planarians- found in fresh water a. nerve cells in head act as a simple brain b. have sense organs called "eye spots." c. regenerate, or re grow missing body parts.

7. 3. Most flatworms are parasites. a. parasite: animal that depends on and harms another plant or animal. b. animal or plant being harmed is the host. c. tapeworm lives in digestive system, and eats host's digested food.

8. B. Round Worms 1. long, tube-shaped body with a digestive system 2. most live in soil and eat dead plant and animal matter. 3. some are parasites found in dogs, cats, and other animals. (heart worms)

9. C. Segmented Worms 1. bodies divided into sections, or rings. 2. have a series of hearts that pump blood through the body. 3. have a digestive system. 4. earthworms, or night crawlers live in wet soil. a. have bristles on each segment, except first and last (setae) b. "farmer's friends" 1. make tunnels for water and oxygen 2. recondition the soil.

10. V. Echinoderms A. invertebrates with spiny skin. 1. spine: sharp, pointy structure 2. body is hard and covered with spines B. live in ocean C. Sea stars 1. have tube feet with suckers on the ends 2. use tube feet to move 3. uses tube feet to get food a. pry open shell fish b. stomach (center of star) inverts, goes into clam, and dissolves food. 4. can regenerate arms

11. A. invertebrate with a soft body B. most live in ocean, some in fresh water, or land. C. some have one shell, two shells, or no shells. D. More complex 1. beginnings of a true eye 2. blood is pumped through blood vessels throughout the body. VI. Mollusks

12. E. Two-shelled Mollusks 1. clams, oysters, scallops 2. shells held together by muscles 3. have foot which is used for digging, and moving F. Snails and Slugs 1. have large muscular foot that gives off a layer of slime. 2. move by gliding on slime 3. snails, limpets, periwinkles: one shell 4. slugs: no shell

13. G. Mollusks with no shells 1. squid and octopus 2. have long tentacles lined with suckers to help them catch food 3. have ink sac to protect themselves a. cloud of ink in water b. escape enemies without being seen.

14. H. Human uses for mollusks 1. food 2. oysters: pearls a. grain of sand enters shell b. cells inside oyster form nacre around sand c. nacre keeps layering and after many years, a pearl is formed

15. VII. Arthropods A. animals with jointed legs and segmented bodies B. largest group of animals C. most complex invertebrate D. Exoskeleton 1. hard outer covering 2. protects animals soft body parts E. have well-developed sense organs and special mouth parts.

16. F. There are 4 main groups of arthropods. 1. "pedes" a. millipedes: wormlike with many legs; harmless and eats plants. b. centipedes: wormlike with fewer legs; harmful and eats other animals. 2. Crustaceans a. live in water b. lobsters, shrimp, crayfish c. have 5 pairs of legs d. body has 2 segments

17. 3. Arachnids a. spiders, ticks, and mites b. have 4 pairs of legs and 2 body parts c. most spiders harmless 1. make webs to capture prey 2. black widow: harmful d. ticks and mites are parasites.

18. 4. Insects a. largest group of arthropods b. 3 body parts and 3 pairs of legs 1. head 2. thorax (where wings and legs are 3. abdomen c. compound eyes: have thousands of lenses that allow insect to see motion.

19. d. antennae: 2 feelers that help them smell and feel (sometimes taste and hear) e. insects have special mouth parts. 1. chewing (leaves) 2. sucking (nectar) 3. piercing (piercing skin and sucking blood)

20. f. Insects molt or shed their skin. g. Insects are helpful and harmful. 1. helpful a. feed on insects that can destroy crops b. can be food 2. harmful a. carry disease b. destroy crops c. Termites: eat wood