Chapter 2: Interactions in Ecosystems pg. 32

1. Chapter 2: Interactions in Ecosystems pg. 32

2. 2.1 Types of Interactions p. 34 Symbiosis: • is a biological relationship in which two species live closely together over time. • Helps each species survive by providing food, shelter and protection. • 3 types of relationships exist: • Parasitism • Mutualism • Commensalism

5. a. Parasitism • One partner is called the “host” and the other a “parasite”. • Host is usually bigger and is harmed • Host does not usually die but their lifespan may be shortened. • Parasite obtains food and shelter from host and benefits. • Parasites can be internal or external.

6. Internal Parasites • Live inside bodies of hosts • May stay a long time. • Ex. Tapeworms, roundworms

7. External Parasites • Live on the surface of hosts • May stay a short time to feed and reproduce

14. b. Mutualism • Both partners benefit • Ex. Lichens, bees and flowers, termites

15. lichens • Grow on solid surfaces like rocks and trees • Consist of an algae and a fungus living together

16. Lichens • Algae makes sugar just like plants which is food for both • Fungus anchors both organisms to a surface and absorbs water needed by both

17. Insects and flowers • Insects carry pollen away and help reproduction • Flower provides food (nectar) to the insects

18. mutualism • Bacteria living inside humans • Birds living on zebras and rhinos • Algae living on backs of spider crabs • Microorganisms living in the gut of termites • Sea anemones and hermit crabs

19. c. Commensalism • One partner benefits and the other does not gain or lose anything.

20. Ex. Barnacles on the back of a whale

21. Ex. Birds follow army ants

22. Birds riding on water buffalo

23. Food and Populations pg. 37 • Symbiosis helps an organism survive because it provides: ______________ • Predators • are organisms that hunt and kill their food • Are carnivores or meat eaters • Ex. ______________________________

25. Cont’d… • Prey - are organisms that are hunted and killed for prey. - ex._____________________________

26. Predator-Prey Relationships • often show changes in the size of each population that repeats in a cycle. • size of predator population is affected by the number of prey that are available • size of predator population is affected by the number of prey hunting them

28. Lynx- Hare Populations

29. 2.2 Roles of Organisms in Ecosystems (Niche) Producer Consumer Organisms that get their food by eating other organisms a. Herbivores b. Carnivores c. Omnivores d. Scavengers e. Decomposers • Organisms that make their own food through a process called photosynthesis. • Ex. Plants, algae, some bacteria

32. Photosynthesis – Producers/Autotrophs

35. Bacteria – algae that live ina pond

36. Plants – over 300 000 species on Earth

37. Diatoms – plankton live in the ocean

38. Types of Consumers • Herbivores - eat only plants ex.

40. b. carnivores • Hunt and eat other animals • Ex.

41. c. omnivores • Eat both plants and animals

43. d. scavengers • Eat remains of dead plants and animals • Ex. Seagulls, crows, blackbears, raven, hawk, eagle

44. e. decomposers • Do not ingest food • Release digestive juices to the environment which break down remains of dead organisms and waste • Absorb the digested from back in • Ex. Bacteria, fungus, insects

47. Decomposers and Food pg. 43 • Food can be protected from decomposers by: • Keeping microorganisms out of it. (bacteria, fungus, ) • Vacuum packed products • Caning • Sealed plastic bags and containers • Freezing • Freeze Drying • Salting and pickling

48. Micro-organisms • Need a source of food • Need water • Have a range of tolerance for temperature and ph

49. a. Vacuum Packed Products

50. b. Canning