AP Environmental Science & Ecology 1 — Questions and Answers
Question 1: What is the primary driving force behind the water cycle?
- Photosynthesis
- Solar energy (Correct answer)
- Gravitational pull
- Wind patterns
Correct answer: Solar energy
Solar energy drives evaporation, the process that initiates the water cycle by converting liquid water into vapor.
Question 2: Which biogeochemical cycle is most directly disrupted by burning fossil fuels?
- Nitrogen cycle
- Phosphorus cycle
- Carbon cycle (Correct answer)
- Sulfur cycle
Correct answer: Carbon cycle
Burning fossil fuels releases stored carbon as CO2 into the atmosphere, directly disrupting the carbon cycle's natural balance.
Question 3: In a food web, which organisms occupy the highest trophic level?
- Producers
- Primary consumers
- Secondary consumers
- Tertiary consumers (Correct answer)
Correct answer: Tertiary consumers
Tertiary consumers eat secondary consumers and receive energy that has passed through all lower trophic levels, placing them at the apex.
Question 4: Which of the following best describes a keystone species?
- The most abundant species in an ecosystem
- A species with a disproportionately large impact on its ecosystem (Correct answer)
- A species found only in one geographic location
- A species at the base of the food web
Correct answer: A species with a disproportionately large impact on its ecosystem
A keystone species has effects on ecosystem structure far greater than expected from its abundance, often controlling community composition.
Question 5: What process converts atmospheric nitrogen gas (N2) into forms that plants can absorb?
- Denitrification
- Nitrogen fixation (Correct answer)
- Decomposition
- Photosynthesis
Correct answer: Nitrogen fixation
Nitrogen fixation, performed by bacteria such as Rhizobium, converts N2 into ammonia (NH3) that plants can take up through their roots.
Question 6: The CITES international treaty primarily regulates which environmental concern?
- Greenhouse gas emissions
- Trade in endangered species (Correct answer)
- Ocean pollution
- Tropical deforestation
Correct answer: Trade in endangered species
CITES (Convention on International Trade in Endangered Species) controls international commercial trade in threatened plants and animals.
Question 7: Which term describes the number of different species present in a defined geographic area?
- Genetic diversity
- Species richness (Correct answer)
- Ecosystem diversity
- Biomass
Correct answer: Species richness
Species richness counts the number of distinct species in an area and is a fundamental measure of local biodiversity.
AP Environmental Science & Ecology 1
What is the primary driving force behind the water cycle?