1. Studying the Web of Life
Ecology – the study of the interactions between organisms and their environment
Environments have 2 parts:
Biotic – living things in environment
Abiotic – physical factors of environment (water, soil, light, temperature, etc.)

2. Levels of Environmental Organization
Organism – single individual

3. Levels of Environmental Organization
2. Population – group of individuals of the same species that live together in the same area at the same time - individuals in a population compete with one another for food, nesting space, and mates

4. Levels of Environmental Organization
3. Community – consists of all the populations of different species that live and interact in an area
- different populations in a community depend on each other for food, shelter, and many other things

5. Levels of Environmental Organization
4. Ecosystem – community and its abiotic environment.

6. Levels of Environmental Organization
5. Biosphere – part of the Earth where life exist

7. Living Things Need Energy
All living things need energy to survive.
Organisms can be divided into 3 groups based on how they obtain energy:
Producers – organisms that use sunlight directly to make food
Consumers – organisms that eat producers or other organisms
Decomposers – organisms that get energy by breaking down dead or decaying organisms

8. Producers Use photosynthesis
Mostly plants, but also algae and some bacteria

9. Consumers Cannot use sun’s energy directly Herbivore – eats plants
Carnivore – eats animals
Omnivore – eat both plants and animals
Scavengers – feed on bodies of dead animals

10. Decomposers Bacteria and fungi
Extract the last bit of energy from dead organisms and produce simpler materials
Nature’s recyclers

11. Food Chains
Food Chains – represents how the energy in food molecules flows from one organism to the next

12. Food Webs
Food Web – many energy pathways between organisms

13. Energy Pyramid
The loss of energy at each level of the food chain can be represented by an energy pyramid
Each level uses 90% of the energy it obtains, so only 10% of the energy is passed along to the next level

14. Habitat and Niche Habitat – the environment in which an organism lives
Niche – an organism’s way of life within an ecosystem
Includes its habitat, food, predators, organisms with which it competes, how the organism affects and is affected by abiotic factors in its environment

15. Interactions with the Environment
An organism interacts with biotic or abiotic factors in its environment that can control the size of its population
Limiting Factors – factors that influence how large a population can grow to
Ex: food, water, living space, other natural resources
Carrying Capacity – the largest population that a given environment can support over a long period of time

16. Interactions Among Organisms
4 main ways that species and individuals affect each other:
Competition
Predators and Prey
Symbiotic relationships
Coevolution

17. Competition
When 2 or more individuals or populations try to use the same limited resource (ex: food, water, shelter, space, sunlight, etc.)
Can occur among individuals within a population
Can occur between populations of different species

18. Predators and Prey Prey – organism that is eaten
Predator – organism that eats the prey
Predator Adaptations –
Canines
Claws
Camouflage
Speed
Prey Adaptations –
Chemical combat Camouflage Speed Trickery: false features and mimicry

19. Symbiosis Close, long-term association between two or more species
3 Main Groups
Mutualism
Commensalism
Parasitism

20. Mutualism Symbiotic relationship in which both organisms benefit
Examples:
You and a species of bacteria in your intestines
Coral and algae

21. Commensalism
Symbiotic relationship in which one organism benefits and the other organism is unaffected
Examples:
Sharks and remoras

22. Parasitism
Symbiotic relationship in which one organism benefits while the other organism is harmed
Parasite – organism that benefits
Host – organism that is harmed
Example:
Tomato hornworm and wasps

23. Coevolution
Long-term change that takes place in two species because of their close interactions with one another
Flowers and their Pollinators
Acacia Trees and Acacia Ants
Yucca Moth and Yucca Plants