Interactions Within Communities

1. Interactions Within Communities Chapter 12 Lesson 3 Notes

2. Interactions within Communities • Sun – source of energy that fuels most life on Earth.

3. Producers • Producers – organisms that use an outside energy source to make energy-rich molecules. • Most producers use the Sun and contain chlorophyll, a chemical required for photosynthesis. Photosynthesis Equation H2O CO2 C6H12O6 O2 Water Carbon Dioxide Sugar Oxygen + +

4. Producers • Some producers, found near volcanic vents on the ocean floor, use mineral molecules as energy source for chemosynthesis (using chemicals to make food). National Geographic Video

5. Consumers • Consumers – organisms that cannot make their own energy-rich molecules; they obtain energy by eating other organisms.

6. Consumers • Herbivores, such as deer and rabbits eat plants.

7. Consumers • Carnivores, such as frogs and lions, eat animals.

8. Consumers • Omnivores, such as pigs and humans, eat both plants and animals.

9. Decomposers • Decomposers, such as earthworms and bacteria, eat dead organisms.

10. Food Chain • Food chain – a model that shows the feeding relationships among the organisms in an ecosystem.

11. Symbiosis Symbiosis – any close relationship between species.

12. Symbiosis Mutualism – a symbiotic relationship in which both species benefit. Shrimp and Goby Video

13. Symbiosis Commensalism – a symbiotic relationship in which one organism benefits and the other is not affected. Commensalism The sea anemone protects the clownfish from predators. The clownfish benefits, but the sea anemone is not helped or hurt.

14. Symbiosis Parasitism – a symbiotic relationship in which one organism benefits and the other is harmed. Parasitism Some roundworms are parasites that rob nutrients from their hosts.

15. Niches • Niche – a species’ unique requirements for survival, including its habitat and food, and how it avoids danger, finds a mate and cares for its young.

16. Predator and Prey Predator and Prey • Predator – consumer that captures and eats other consumers. • Prey – the organism that is eaten. • Predators limit the size of prey populations, increasing the number of different species that can live in an ecosystem.

18. Cooperative Actions • Cooperative actions improve a species’ survival. • Example: one deer warns the others of predators in the area. • Example: individual ants perform different tasks required for the survival of all.