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VirginiaBiology

Reporting Category 4: Classification, Evolution, and Ecology

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does energy flow through an ecosystem, and why does it limit the number of trophic levels?

Explain how energy flows through ecosystems through food chains, food webs, and trophic levels, including the roles of producers, consumers, and decomposers and the ten percent rule (Virginia 2018 Biology SOL BIO.8.b).
A SOL-level answer on energy flow for the Virginia Biology EOC: producers, consumers, and decomposers; food chains, food webs, and trophic levels; energy pyramids and the ten percent rule; and why energy flows one way while matter cycles, with worked calculations.
13 min answer →

How do natural events and human activities change Virginia's ecosystems?

Explain how natural events and human activities influence local and global ecosystems and may affect the flora and fauna of Virginia, including the Chesapeake Bay watershed, invasive species, and eutrophication (Virginia 2018 Biology SOL BIO.8.d).
A SOL-level answer on human impact for the Virginia Biology EOC: the Chesapeake Bay watershed and how nutrient runoff causes eutrophication and dead zones, invasive species and biodiversity loss, habitat change and pollution, and the conservation responses, with the Virginia-specific examples the EOC uses.
12 min answer →

How do nutrients cycle through ecosystems, and how do communities change through succession?

Describe how the carbon, nitrogen, and water cycles move nutrients through ecosystems, and explain primary and secondary ecological succession (Virginia 2018 Biology SOL BIO.8.b and BIO.8.c).
A SOL-level answer on nutrient cycling and succession for the Virginia Biology EOC: the carbon, nitrogen, and water cycles and the roles of photosynthesis, respiration, decomposers, and bacteria; and primary versus secondary succession from pioneer species to a stable climax community.
13 min answer →

What determines how large a population can grow in an ecosystem?

Explain population dynamics, including carrying capacity, limiting factors, growth curves, and density-dependent and density-independent factors (Virginia 2018 Biology SOL BIO.8.a).
A SOL-level answer on population dynamics for the Virginia Biology EOC: exponential versus logistic growth curves, carrying capacity, limiting factors, density-dependent and density-independent factors, and predator-prey relationships, with the graphs the EOC asks you to read.
12 min answer →