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LS2: Ecosystems (Interactions, Energy, and Dynamics)

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is matter cycled through an ecosystem?

Develop a model to illustrate the cycling of matter, including the role of photosynthesis and cellular respiration in the carbon cycle (Louisiana Student Standards for Science, High School Biology, HS-LS2-5).
A standard-level answer on the cycling of matter for Louisiana LEAP 2025 Biology: the carbon cycle, the role of photosynthesis and respiration, decomposition, and the nitrogen cycle, and how matter is recycled while energy flows one way.
13 min answer →

What makes an ecosystem stable and able to recover from disturbance?

Use mathematical representations to support claims about how biodiversity and interactions affect the stability and resilience of ecosystems (Louisiana Student Standards for Science, High School Biology, HS-LS2-2).
A standard-level answer on ecosystem stability for Louisiana LEAP 2025 Biology: how biodiversity and species interactions support stability and resilience, keystone species, and how ecosystems respond to and recover from disturbance.
12 min answer →

How does energy flow through the organisms of an ecosystem?

Use mathematical representations to support explanations of the flow of energy through food chains and food webs in an ecosystem (Louisiana Student Standards for Science, High School Biology, HS-LS2-4).
A standard-level answer on energy flow for Louisiana LEAP 2025 Biology: producers and consumers, food chains and webs, trophic levels, the ten percent rule, and why energy pyramids narrow toward the top.
13 min answer →

How do human activities affect ecosystems, and how can we reduce the harm?

Design, evaluate, and refine a solution for reducing the adverse impacts of human activity on the environment and biodiversity (Louisiana Student Standards for Science, High School Biology, HS-LS2-7).
A standard-level answer on human impact for Louisiana LEAP 2025 Biology: habitat loss, pollution, climate change, and invasive species, and how to design and evaluate solutions that reduce harm to ecosystems and biodiversity.
12 min answer →

What factors determine the carrying capacity of an ecosystem for a population?

Use mathematical and computational representations to explain the factors that affect the carrying capacity and growth of populations in an ecosystem (Louisiana Student Standards for Science, High School Biology, HS-LS2-1).
A standard-level answer on population dynamics for Louisiana LEAP 2025 Biology: carrying capacity, limiting factors, exponential and logistic growth, and how density-dependent and density-independent factors control populations.
13 min answer →