AP Environmental Science — Unit 2: The Living World: Biodiversity

What AP Environmental Science Unit 2 covers

The College Board Course and Exam Description breaks Unit 2 into 7 topics:

1. 2.1 Introduction to Biodiversity
2. 2.2 Ecosystem Services
3. 2.3 Island Biogeography
4. 2.4 Ecological Tolerance
5. 2.5 Natural Disruptions to Ecosystems
6. 2.6 Adaptations
7. 2.7 Ecological Succession

AP Environmental Science Unit 2 practice questions

• What are the three levels of biodiversity recognized in an ecosystem?

  Genetic diversity, species diversity, and habitat diversity

• A cheetah population crashes to fewer than 50 individuals. What long-term consequence does this population bottleneck create?

  Reduced genetic diversity, leaving the population less adaptable. With fewer alleles, it can't respond well to disease or climate shifts.

• Why do ecosystems with higher species richness tend to recover faster from disruptions?

  More species means functional redundancy, so others fill a lost species' role. This is why richer ecosystems recover faster from disruption.

• A forest is fragmented by a new highway. Which species disappear first — specialists or generalists?

  Specialist species disappear first; generalists are lost later. Generalists tolerate more conditions, so they persist as habitat keeps shrinking.

• Pond A has 10,000 fish but only 3 species. Pond B has 200 fish spread across 30 species. Which pond has higher species richness?

  Pond B — richness counts how many different species are present. It ignores total headcount, so 30 species beats 3 regardless of fish numbers.

• A forest pulls timber and fresh water out of the landscape for people to harvest directly. Which category of ecosystem service is this — and the one students most often confuse with 'regulating'?

  Provisioning services — tangible products people harvest directly from nature. Think food, timber, and fresh water; things you can carry away.

• A wetland filters pollutants from runoff AND provides recreational fishing. Which ecosystem service categories do these represent, respectively?

  Filtering pollutants = regulating service; recreational fishing = cultural service

• A coastal mangrove forest is cleared for a resort. What are the likely ecological AND economic consequences?

  Losing storm-surge protection and fish-nursery habitat raises flood costs. Both a regulating and a supporting service vanish, hurting ecology and fishery yields.

+ 17 more AP Environmental Science cards in the app.

Key terms in Unit 2

These 12 terms show up in the Unit 2 cards. Each one links to its definition in the AP Environmental Science key-term reference.

• Ecological tolerance
• Ecosystem services
• Genetic diversity
• Habitat diversity
• Indicator species
• Island biogeography
• Natural disruption
• Population bottleneck
• Primary succession
• Provisioning services
• Specialist species
• Supporting services