1. Interactions of Life
Chapter 24

2. Living Earth
The part of Earth that supports life is called the biosphere.
Top portion of the crust, all the waters and the atmosphere that surrounds Earth.
The biosphere is made up of different environments that are home to different kinds of organisms.
Desert environments vs. tropical environments.

3. Ecology: the study of interactions that occur among organisms and their environment
An ecosystem is all the organisms living in an area as well as the nonliving parts of that environment.
A population is made up of all the organisms in an ecosystem that belong to the same species.
All of the grasshoppers in the prairie.
A community is all the population of all species living in an ecosystem.
All of the bison, grasshoppers, birds, etc. in the prairie.

4. Each organism in an ecosystem needs a place to live…
Habitat – the place where an organism lives.
In the rainforest, some birds live inside of dead trees while salamanders live beneath fallen leaves and twigs.
An organism’s habitat provides the kinds of food and shelter, the temperature and the amount of moisture the organism needs to survive.

5. Biosphere
Ecosystem
Community
Population

6. Biosphere  Ecosystem  Community  Population
Ecology Flow Chart
Biosphere  Ecosystem  Community  Population
Pick an ecosystem (Tropical rainforest, Subtropical savannas, Deserts and semi-deserts, Oceans, Temperate grasslands, Temperate forests, Coniferous forests, Alpine and polar regions)
Create an ecology flowchart using irregular shapes.
Start big (at biosphere) and “zoom in” (to population)
Make sure you keep in mind the climate of your ecosystem and all of the living organisms that would be involved.
Underneath each picture, write a caption so that I know what I’m looking at and so I know that you know what each level is.

7. Populations
Competition: when two or more organisms seek the same resource at the same time.
Competition for food, living space, or other resources can limit a population’s size.
Competition is usually most intense between members of the same species.
why?
Population size indicates whether a population is healthy and growing.
Population density is the size of a population that occupies a specific area.

8. Elements that affect population size…
Limiting factor: any living or nonliving feature that restricts the number of individuals in a population.
Carrying capacity: the largest number of individuals of one species that an ecosystem can support.
Biotic potential: the highest rate of reproduction under ideal conditions.
Pumpkins vs. peaches
Birth and death rates
Movement of organisms into or out of an area.

9. Interactions within communities
Producers: organisms that use an outside energy source (like the sun) to make energy-rich molecules.
Plants use photosynthesis
Consumers: organisms that cannot make their own energy-rich molecules and instead obtain energy by eating other organisms.
4 types of consumers

10. Four types of Consumers
Herbivores: eat plants
Deer and rabbits
Carnivores: eat animals
Frogs and lions
Omnivores: eat both plants and animals
Pigs and humans
Decomposers: eat dead organisms
Earthworms and bacteria

11. Food Chain!
Food chain: a model that shows the feeding relationships among the organisms in an ecosystem.

12. Can’t we all just get along?
Symbiosis: any close relationship between species.
Mutualism: a symbiotic relationship in which both species benefit.
Commensalism: a symbiotic relationship in which one organism benefits and the other is not affected.
Parasitism: a symbiotic relationship in which one organism benefits and the other is harmed.

13. Can’t we all just get along?
Niche: an organism’s role in its environment, including its habitat and food, and how it avoids danger, finds a mate and cares for its young.
Predator and Prey!!
Predator: consumer that captures and eats other consumers.
Prey: The organism that is captured by the predator.
Predators limit the size of prey populations, increasing the number of different species that can live in an ecosystem.
Cooperative actions improve a species’ survival
One deer warns others of predators in the area
Individual ants perform different tasks required for the survival of all