2026
,Table of Contents
How to Use This Book
Barron’s Essential 5
Questions Commonly Asked About the APES Exam
1 The Living World: Ecosystems
1.1 Introduction to Ecosystems
1.2 Terrestrial Biomes
1.3 Aquatic Biomes
1.4 The Carbon Cycle
1.5 The Nitrogen Cycle
1.6 The Phosphorus Cycle
1.7 The Hydrologic (Water) Cycle
1.8 Primary Productivity
1.9 Trophic Levels
1.10 Energy Flow and the 10% Rule
1.11 Food Chains and Food Webs
Practice Questions
Answer Explanations
2 The Living World: Biodiversity
2.1 Introduction to Biodiversity
2.2 Ecosystem Services
2.3 Island Biogeography
, 2.4 Ecological Tolerance
2.5 Natural Disruptions to Ecosystems
2.6 Adaptations
2.7 Ecological Succession
Practice Questions
Answer Explanations
3 Populations
3.1 Generalist and Specialist Species
3.2 K-Selected and r-Selected Species
3.3 Survivorship Curves
3.4 Carrying Capacity
3.5 Population Growth and Resource Availability
3.6 Age-Structure Diagrams
3.7 Total Fertility Rate
3.8 Human Population Dynamics
3.9 Demographic Transition
Practice Questions
Answer Explanations
4 Earth Systems and Resources
4.1 Plate Tectonics
4.2 Soil Formation and Erosion
4.3 Soil Composition and Properties
4.4 Earth’s Atmosphere
4.5 Global Wind Patterns
4.6 Watersheds
4.7 Solar Radiation and Earth’s Seasons
4.8 Earth’s Geography and Climate
4.9 El Niño and La Niña
, Practice Questions
Answer Explanations
5 Land and Water Use
5.1 “The Tragedy of the Commons”
5.2 Clearcutting
5.3 The Agricultural and Green Revolutions
5.4 Impacts of Agricultural Practices
5.5 Irrigation Methods
5.6 Pest Control Methods
5.7 Meat Production Methods
5.8 Impacts of Overfishing
5.9 Impacts of Mining
5.10 Impacts of Urbanization
5.11 Ecological Footprints
5.12 Introduction to Sustainability
5.13 Methods to Reduce Urban Runoff
5.14 Integrated Pest Management
5.15 Sustainable Agriculture
5.16 Aquaculture
5.17 Sustainable Forestry
Practice Questions
Answer Explanations
6 Energy Resources and Consumption
6.1 Renewable and Nonrenewable Resources
6.2 Global Energy Consumption
6.3 Fuel Types and Uses
6.4 Distribution of Natural Energy Sources
6.5 Fossil Fuels
,Table of Contents
How to Use This Book
Barron’s Essential 5
Questions Commonly Asked About the APES Exam
1 The Living World: Ecosystems
1.1 Introduction to Ecosystems
1.2 Terrestrial Biomes
1.3 Aquatic Biomes
1.4 The Carbon Cycle
1.5 The Nitrogen Cycle
1.6 The Phosphorus Cycle
1.7 The Hydrologic (Water) Cycle
1.8 Primary Productivity
1.9 Trophic Levels
1.10 Energy Flow and the 10% Rule
1.11 Food Chains and Food Webs
Practice Questions
Answer Explanations
2 The Living World: Biodiversity
2.1 Introduction to Biodiversity
2.2 Ecosystem Services
2.3 Island Biogeography
, 2.4 Ecological Tolerance
2.5 Natural Disruptions to Ecosystems
2.6 Adaptations
2.7 Ecological Succession
Practice Questions
Answer Explanations
3 Populations
3.1 Generalist and Specialist Species
3.2 K-Selected and r-Selected Species
3.3 Survivorship Curves
3.4 Carrying Capacity
3.5 Population Growth and Resource Availability
3.6 Age-Structure Diagrams
3.7 Total Fertility Rate
3.8 Human Population Dynamics
3.9 Demographic Transition
Practice Questions
Answer Explanations
4 Earth Systems and Resources
4.1 Plate Tectonics
4.2 Soil Formation and Erosion
4.3 Soil Composition and Properties
4.4 Earth’s Atmosphere
4.5 Global Wind Patterns
4.6 Watersheds
4.7 Solar Radiation and Earth’s Seasons
4.8 Earth’s Geography and Climate
4.9 El Niño and La Niña
, Practice Questions
Answer Explanations
5 Land and Water Use
5.1 “The Tragedy of the Commons”
5.2 Clearcutting
5.3 The Agricultural and Green Revolutions
5.4 Impacts of Agricultural Practices
5.5 Irrigation Methods
5.6 Pest Control Methods
5.7 Meat Production Methods
5.8 Impacts of Overfishing
5.9 Impacts of Mining
5.10 Impacts of Urbanization
5.11 Ecological Footprints
5.12 Introduction to Sustainability
5.13 Methods to Reduce Urban Runoff
5.14 Integrated Pest Management
5.15 Sustainable Agriculture
5.16 Aquaculture
5.17 Sustainable Forestry
Practice Questions
Answer Explanations
6 Energy Resources and Consumption
6.1 Renewable and Nonrenewable Resources
6.2 Global Energy Consumption
6.3 Fuel Types and Uses
6.4 Distribution of Natural Energy Sources
6.5 Fossil Fuels
