1. Ecology

2. Levels of Organization
1. Organism
2. Population
A group of individuals that are the same species, live in the same area and breed with others in the group

3. Levels of Organization
3. Community
4. Ecosystem
Different populations that live together in a defined area
All the organisms that live in a particular area together with their nonliving environment

4. Levels of Organization
5. Biome
6. Biosphere
Group of ecosystems that have the same climate and dominant communities
Part of the earth in which all life exists

5. Biosphere
Biome
Ecosystem
Community
Population
Individual

6. What Shapes an Ecosystem?
Ecosystems are influenced by biological and physical factors
Biotic Factors
living organisms in a habitat
includes birds, bacteria, mushrooms, plants, etc
Abiotic Factors
Physical or nonliving factors
Includes temperature, water, soil, weather

7. What Shapes an Ecosystem?
Habitat
The place where a particular species lives
Niche
The role an organism plays in an ecosystem
Includes:
How it meets its need for food and shelter
How it survives
How it reproduces
Habitat – “address”
Niche – “occupation” or “job”

8. Habitats & Niches – Tree Stump
Earthworm obtains nutrients from organic material it eats
Centipede captures and eats beetles

9. Habitats & Niches – Forest Litter
Scavenges dead animals
Scavenges dead plants

10. Community Interactions
Competition and predation are two important ways in which organisms interact.
Competition occurs when two organisms fight for the same limited resource.

11. Predation
occurs when one organism captures and eats another.

12. Community Interactions
Symbiosis
2 or more species that live together in a close association or relationship
Examples include:
Mutualism
Commensalism
Parasitism

13. Community Interactions
Mutualism
Relationship in which both organisms benefit

15. Community Interactions
Commensalism
Relationship in which one benefits while the other is neither helped nor harmed
Human Our eyelashes are home to tiny mites
that feast on oil secretions and dead skin. Without harming us, up to 20 mites may be living in one eyelash follicle.
Demodicids Eyelash mites find all they need to survive in the tiny follicles
of eyelashes. Magnified here 225 times, these creatures measure 0.4 mm in length and can be seen only with a microscope. +
Organism benefits Ø
Organism is not affected
Commensalism

17. Community Interactions
Parasitism
Relationship in which one benefits while the other harmed
Organism benefits _
Organism is not affected
Hornworm caterpillar
The host hornworm will eventually die as its organs are consumed
by wasp larvae.
Braconid wasp
Braconid larvae feed on their host and release themselves shortly before reaching
the pupae stage of development.
Parasitism +

19. Observing and Inferring From the data, it is clear that the association between the organisms is
a. commensalism c. mutualism
b. parasitism d. socialism