AP Environmental Science — Unit 4: Earth Systems and Resources
Practice questions, answers, and key terms for Unit 4, aligned to the College Board CED.
Exam weighting: Unit 4 is 10-15% of the AP Environmental Science exam.
What AP Environmental Science Unit 4 covers
The College Board Course and Exam Description breaks Unit 4 into 9 topics:
- 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
AP Environmental Science Unit 4 practice questions
What geological features form at a convergent boundary where an oceanic plate subducts beneath a continental plate?
Volcanoes, mountains, earthquakes. The denser oceanic plate melts and drives magma upward.
Two oceanic plates move away from each other at a divergent boundary. What happens at the gap between them?
Seafloor spreading — magma rises to form new crust. It builds a mid-ocean ridge as the plates separate.
Two plates slide horizontally past each other without colliding or separating. What type of boundary is this, and what hazard does it produce?
A transform boundary, which produces earthquakes only. No volcanism or mountain building occurs.
What triggers an earthquake along a fault?
Stress builds on a locked fault until it slips suddenly. The slip releases stored energy as seismic waves.
How does a hotspot differ from a plate boundary in terms of location and geological activity?
Hotspots are stationary mantle plumes away from plate boundaries. As a plate drifts over one, a volcano chain forms (e.g., Hawaii).
What is 'parent material' in the context of soil formation?
The original rock or mineral deposit that weathers into soil. It is weathered, transported, and deposited over time.
List the major soil horizons from the surface downward and describe what distinguishes the O and A horizons.
O, A, B, C downward; O is organic litter, A is fertile topsoil. B is subsoil mineral accumulation; C is weathered parent material.
How does healthy soil protect water quality in a watershed?
Soil acts as a natural filter, trapping contaminants as water percolates through. Sediments and pathogens are caught before reaching groundwater or streams.
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Key terms in Unit 4
These 12 terms show up in the Unit 4 cards. Each one links to its definition in the AP Environmental Science key-term reference.
Drill all of Unit 4 with spaced repetition
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