AP®︎ Environmental Science: Unit 1 Practice Test
Prepare for your quiz, test, or the AP exam with focused practice questions on Unit 1 of AP Environmental Science – The Living World: Ecosystems.
Questions List
Unit 1 (All Topics)
Question 1 Topic 1.1Easy
This question tests the following: ERT-1.A.1
What is a predator in a predator-prey relationship?
What You’re Being Tested On:
Explore the learning objectives taken directly from the College Board’s AP® Environmental Science Curriculum. Ensure you’re prepared for the exact topics covered on the AP® exam, in-class tests, and quizzes, and gain confidence in your mastery of the material.
Unit 1: The Living World: Ecosystems
This unit explores ecosystems and energy flow, including biomes, cycles of matter, and food chains that form the foundation of ecological understanding.
Topic 1.1: Introduction to Ecosystems
Learning Objective: ERT-1.A
Explain how the availability of resources influences species interactions.
Essential Knowledge: ERT-1.A.1
In a predator-prey relationship, the predator is an organism that eats another organism (the prey).
Essential Knowledge: ERT-1.A.2
Symbiosis is a close and long-term interaction between two species in an ecosystem. Types of symbiosis include mutualism, commensalism, and parasitism.
Essential Knowledge: ERT-1.A.3
Competition can occur within or between species in an ecosystem where there are limited resources. Resource partitioning—using the resources in different ways, places, or at different times—can reduce the negative impact of competition on survival.
Topic 1.2: Terrestrial Biomes
Learning Objective: ERT-1.B
Describe the global distribution and principal environmental aspects of terrestrial biomes.
Essential Knowledge: ERT-1.B.1
A biome contains characteristic communities of plants and animals that result from, and are adapted to, its climate.
Essential Knowledge: ERT-1.B.2
Major terrestrial biomes include taiga, temperate rainforests, temperate seasonal forests, tropical rainforests, shrubland, temperate grassland, savanna, desert, and tundra.
Essential Knowledge: ERT-1.B.3
The global distribution of nonmineral terrestrial natural resources, such as water and trees for lumber, varies because of some combination of climate, geography, latitude and altitude, nutrient availability, and soil.
Essential Knowledge: ERT-1.B.4
The worldwide distribution of biomes is dynamic; the distribution has changed in the past and may again shift as a result of global climate changes.
Topic 1.3: Aquatic Biomes
Learning Objective: ERT-1.C
Describe the global distribution and principal environmental aspects of aquatic biomes.
Essential Knowledge: ERT-1.C.1
Freshwater biomes include streams, rivers, ponds, and lakes. These freshwater biomes are a vital resource for drinking water.
Essential Knowledge: ERT-1.C.2
Marine biomes include oceans, coral reefs, marshland, and estuaries. Algae in marine biomes supply a large portion of the Earth’s oxygen, and also take in carbon dioxide from the atmosphere.
Essential Knowledge: ERT-1.C.3
The global distribution of nonmineral marine natural resources, such as different types of fish, varies because of some combination of salinity, depth, turbidity, nutrient availability, and temperature.
Topic 1.4: The Carbon Cycle
Learning Objective: ERT-1.D
Explain the steps and reservoir interactions in the carbon cycle.
Essential Knowledge: ERT-1.D.1
The carbon cycle is the movement of atoms and molecules containing the element carbon between sources and sinks.
Essential Knowledge: ERT-1.D.2
Some of the reservoirs in which carbon compounds occur in the carbon cycle hold those compounds for long periods of time, while some hold them for relatively short periods of time.
Essential Knowledge: ERT-1.D.3
Carbon cycles between photosynthesis and cellular respiration in living things.
Essential Knowledge: ERT-1.D.4
Plant and animal decomposition have led to the storage of carbon over millions of years. The burning of fossil fuels quickly moves that stored carbon into atmospheric carbon, in the form of carbon dioxide.
Topic 1.5: The Nitrogen Cycle
Learning Objective: ERT-1.E
Explain the steps and reservoir interactions in the nitrogen cycle.
Essential Knowledge: ERT-1.E.1
The nitrogen cycle is the movement of atoms and molecules containing the element nitrogen between sources and sinks.
Essential Knowledge: ERT-1.E.2
Most of the reservoirs in which nitrogen compounds occur in the nitrogen cycle hold those compounds for relatively short periods of time.
Essential Knowledge: ERT-1.E.3
Nitrogen fixation is the process in which atmospheric nitrogen is converted into a form of nitrogen (primarily ammonia) that is available for uptake by plants and that can be synthesized into plant tissue.
Essential Knowledge: ERT-1.E.4
The atmosphere is the major reservoir of nitrogen.
Topic 1.6: The Phosphorus Cycle
Learning Objective: ERT-1.F
Explain the steps and reservoir interactions in the phosphorus cycle.
Essential Knowledge: ERT-1.F.1
The phosphorus cycle is the movement of atoms and molecules containing the element phosphorus between sources and sinks.
Essential Knowledge: ERT-1.F.2
The major reservoirs of phosphorus in the phosphorus cycle are rock and sediments that contain phosphorus-bearing minerals.
Essential Knowledge: ERT-1.F.3
There is no atmospheric component in the phosphorus cycle, and the limitations this imposes on the return of phosphorus from the ocean to land make phosphorus naturally scarce in aquatic and many terrestrial ecosystems. In undisturbed ecosystems, phosphorus is the limiting factor in biological systems.
Topic 1.7: The Hydrologic (Water) Cycle
Learning Objective: ERT-1.G
Explain the steps and reservoir interactions in the hydrologic cycle.
Essential Knowledge: ERT-1.G.1
The hydrologic cycle, which is powered by the sun, is the movement of water in its various solid, liquid, and gaseous phases between sources and sinks.
Essential Knowledge: ERT-1.G.2
The oceans are the primary reservoir of water at the Earth’s surface, with ice caps and groundwater acting as much smaller reservoirs.
Topic 1.8: Primary Productivity
Learning Objective: ENG-1.A
Explain how solar energy is acquired and transferred by living organisms.
Essential Knowledge: ENG-1.A.1
Primary productivity is the rate at which solar energy (sunlight) is converted into organic compounds via photosynthesis over a unit of time.
Essential Knowledge: ENG-1.A.2
Gross primary productivity is the total rate of photosynthesis in a given area.
Essential Knowledge: ENG-1.A.3
Net primary productivity is the rate of energy storage by photosynthesizers in a given area, after subtracting the energy lost to respiration.
Essential Knowledge: ENG-1.A.4
Productivity is measured in units of energy per unit area per unit time (e.g., kcal/m²/yr).
Essential Knowledge: ENG-1.A.5
Most red light is absorbed in the upper 1 m of water, and blue light only penetrates deeper than 100 m in the clearest water. This affects photosynthesis in aquatic ecosystems, whose photosynthesizers have adapted mechanisms to address the lack of visible light.
Topic 1.9: Trophic Levels
Learning Objective: ENG-1.B
Explain how energy flows and matter cycles through trophic levels.
Essential Knowledge: ENG-1.B.1
All ecosystems depend on a continuous inflow of high-quality energy in order to maintain their structure and function of transferring matter between the environment and organisms via biogeochemical cycles.
Essential Knowledge: ENG-1.B.2
Biogeochemical cycles are essential for life and each cycle demonstrates the conservation of matter.
Essential Knowledge: ENG-1.B.3
In terrestrial and near-surface marine communities, energy flows from the sun to producers in the lowest trophic levels and then upward to higher trophic levels.
Topic 1.10: Energy Flow and the 10% Rule
Learning Objective: ENG-1.C
Determine how the energy decreases as it flows through ecosystems.
Essential Knowledge: ENG-1.C.1
The 10% rule approximates that in the transfer of energy from one trophic level to the next, only about 10% of the energy is passed on.
Essential Knowledge: ENG-1.C.2
The loss of energy that occurs when energy moves from lower to higher trophic levels can be explained through the laws of thermodynamics.
Topic 1.11: Food Chains and Food Webs
Learning Objective: ENG-1.D
Describe food chains and food webs, and their constituent members by trophic level.
Essential Knowledge: ENG-1.D.1
A food web is a model of an interlocking pattern of food chains that depicts the flow of energy and nutrients in two or more food chains.
Essential Knowledge: ENG-1.D.2
Positive and negative feedback loops can each play a role in food webs. When one species is removed from or added to a specific food web, the rest of the food web can be affected.
