1. Populations and Communities
Table of Contents
Living Things and the Environment
Energy Flow In Ecosystems
Interactions Among Living Things
Populations

2. Living Things and the Environment
Factors in
a Prairie Habitat
A prairie
dog interacts with many biotic and abiotic factors in the prairie habitat.

3. Living Things and the Environment
Biotic and Abiotic Factors
Salt is an abiotic factor found in some environments. To see how the amount of salt affects the hatching of brine shrimp eggs, varying amounts of salt were added to four different 500-mL beakers.

4. Living Things and the Environment
Ecological Organization
The smallest level of organization is the organism. The largest is the entire ecosystem.

5. Energy Flow in Ecosystems
What Happened Here?
While you were hiking, some hungry animals turned your campsite upside down.

6. Energy Flow in Ecosystems
What Happened Here?
Can you determine the order in which the organisms visited the campsite?

7. Energy Flow in Ecosystems
Food Web
A food web consists of many interconnected
food chains.

8. Energy Flow in Ecosystems
Energy Pyramids
Suppose that the producers at the base of an energy pyramid contain 330,000 kilocalories. How much energy would be available at each level of the pyramid?

9. Interactions Among Living Things
Saguaro Community
Look for examples of how organisms interact in this scene.

10. Interactions Among Living Things
Niches
Organisms occupy many niches in an environment.

11. Interactions Among Living Things
Predator-Prey Interactions
On Isle Royale, an island in Lake Superior, the populations of wolves (the predator) and moose (the prey) rise and fall in cycles.

12. Interactions Among Living Things
List the names of the parasites and the hosts.

13. Populations Population Size
Using the data table, create a double bar graph showing alligator births and deaths for four years.

14. Populations Changes in a Rabbit Population
This graph shows how the size of a rabbit population changed over ten years.

15. Populations Population Density of the Flamingos in the Pond
In the pond on the top, there are 10 flamingos in
8 square meters. The population density is 1.25 flamingos per square meter.

16. Populations Relate Cause and Effect
As you read about the four factors that can limit populations, think about cause and effect.