Interactions Among Living Things

1. Interactions Among Living Things

2. Adapting to the Environment • Every organism has a variety of adaptations that are suited to its specific living conditions. • Adaptations of organisms in the desert ecosystem create unique roles for each organism.

3. Niche • The special role an organism plays within a habitat. • Helps reduce competition for food and other resources. • Includes: • Type of food organism eats • How and where it obtains food • Which other species use the organism as food • Physical conditions it requires

4. 3 Species of Warblers & Their Niches Cape May Warbler Feeds at the tips of branches near the top of the tree Bay-Breasted Warbler Feeds in the middle part of the tree Yellow-Rumped Warbler Feeds in the lower part of the tree and at the bases of the middle branches Spruce tree

5. Relationships Between Populations • 3 Types of Interactions Among Organisms • Competition • Predation (Predator & Prey) • Symbiosis • These are density-dependent limiting factors

6. Competition • Struggle between organisms to survive in a habitat with limited resources • Ex. Some plants use chemicals to ward off their competition. Release toxic or poisonous, chemicals to prevent them grow growing near their space.

7. Predation • One organism kills and eats other organism • Predator • Organism that does the killing • Adaptations: Speed, hearing, etc. • Prey • Organism that is killed. • Adaptations: Camouflage, protecting covering, warning color, mimicry

8. Effect of Predation on Population Size

9. Symbiosis • Relationship between two species that benefits at least one of the species. • Types of Symbiotic Relationships • Mutualism (+, +) • Both species benefit • Ex. Bacteria in intestine • Commensalism (+, 0) • One helped, one neither helped nor harmed • Ex. Bird and tree • Parasitism (+, -) • One helped (parasite), one hurt (host) • Ex. Tapeworm and you

10. Types of Limiting Factors • Density – Dependent Limiting Factor • How much they affect the population is influenced by how big the population is. • Ex. Competition for food, water, habitat • Density –Independent Limiting Factor • How much they affect the population is not influenced by how big the population is.

11. Density Independent Limiting Factors • Severe weather • Global disaster • Fire

12. What are Some Possible Explanations for this Population Graph?

13. Summary Questions • Name and define the three major types of interactions among organisms. • List the three types of symbiosis. For each one, explain how the two organisms are affected. • How are parasitism and predation similar? How are they different?