1. Populations and Communities
Table of Contents
Living Things and the Environment
Populations
Interactions Among Living Things
Changes in Communities

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

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

7. 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.

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

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. Changes in Communities
Primary Succession
Primary succession occurs in an area where no soil and no organisms exist.

14. Changes in Communities
Secondary Succession
Secondary succession occurs following a disturbance to an ecosystem, such as clearing a forest for farmland.

15. Changes in Communities
Comparison of Primary and Secondary Succession
Based on the information given, what facts would complete this table?