1. Invertebrates I 12-1: Introduction to Animals 12-2: Sponges & Cnidarians 12-3: Flatworms & Roundworms

2. 12-1: Introduction to Animals Animals are extremely diverse, but they have basic characteristics in common

3. Animal Characteristics Multicellular – made of more than one cell Eukaryotes – cells contain a nucleus Heterotrophic – feed off other organisms; consumers Reproduce sexually – Although some can reproduce asexually

4. Animals have different adaptations that help them survive – Adaptations for obtaining energy some only eat plants (____________) – Example: deer, mice, some fish some only eat other animals (__________) – Example: hawks, lions, sharks some eat plants & animals (____________) – Example: humans, bears, raccoons some eat decaying matter called detritus (_________________) – Example: beetles, millipedes herbivores carnivores omnivores detritivores

5. – Physical adaptations Protective coverings protect them from predators – Examples: shells & quills Size is also a defense Mimicry or camouflage

6. – Camouflage helps predators also tigers & killer whales

7. – Behavioral adaptations Some animals use chemicals to discourage predators Speed allows some animals to outrun predators Traveling in groups helps both predators & prey

8. Animals are classified based on similarities they have in common – 2 major groups of animals depending on whether or not they have a backbone Invertebrates— Vertebrates— no backbone backbone

9. – Symmetry how their body parts are arranged Asymmetrical – Animals do not have a definite shape Radial – Parts arranged in a circle around a center point Bilateral – Halves that are nearly mirror images

10. 12-2: Sponges & Cnidarians Sponges are invertebrates – Sponges have little in common with other animals—probably evolved separately from all other animals

11. – Most are asymmetrical and sessile (do not move around; stuck to the ground) Sponge body is a hollow tube with one opening at the top (osculum) and many small pores along the body tube osculum pores

12. No tissues, organs, or organ systems; very simple Have spicules for protection and support

13. Filter feeders – they pull food and oxygen through their pores and expel wastes through the osculum Most are hermaphrodites – produce both sperm and eggs

14. Can also reproduce asexually by budding and regeneration

15. Cnidarians – invertebrate animals that include corals, sea anemones, jellyfish, hydras, and Portuguese man-of-wars

16. – Most have 2 body forms Polyp—vase shaped and sessile Medusa—bell-shaped and free swimming

17. – Have one body opening and symmetry – Have cell layers arranged into tissues radial

18. – Have a digestive cavity to break down food – Have a system of nerve cells called a nerve net connects all parts of the organism; allows them to sense and respond to the environment

19. – Have tentacles with stinging cells that surround the mouth – They are predators

20. – Reproduce sexually and asexually

21. Most cnidarians fossils are corals Reefs form as corals secrete hard skeletons on those of earlier generations

22. – It takes millions of years for large reefs to form – Reefs are important ecosystems provide shelter for many organisms protects shorelines from erosion some corals produce chemicals that are used in medicines

23. 12-3: Flatworms & Roundworms Worms are invertebrates – soft bodies; circular shape – symmetry – different layers; gives them organs and organ systems bilateral

24. Flatworms – first to evolve bilateral symmetry – start to have different tissues – usually parasites – some free-living – some have mouths

25. – Planarians free-living; feed on small organisms or dead bodies triangular shaped head with eyespots bodies covered with cilia and they produce mucous eyespots

26. usually live under rocks, on plant material, or in fresh water can reproduce asexually by fission or sexually; lay eggs

27. – Flukes parasites; life cycle requires more than one host reproduce sexually; male fertilizes female and she lays eggs can infect lungs, liver, eyes, and other organs

28. – Tapeworms parasites; uses hooks and sucker to attach to hosts’ intestines don’t have digestive tract body is segmented, and as it grows it adds more segments hermaphrodites that fertilize themselves

29. Roundworms – called nematodes – more complex than flatworms – have two body openings—mouth and anus – live almost everywhere!!!

30. – most have separate male and females that reproduce sexually – many are plant and animal parasites (heartworms) – some are helpful—kill pests (termites, fleas, ants, etc.) – also helpful in enriching soil