Evaluate evidence about how human activities (habitat loss, pollution, climate change, and overuse) affect ecosystems and biodiversity, and how conservation can reduce the impact (Tennessee Academic Standards for Science, Biology I, BIO1.LS2).

What this topic is asking

The Tennessee LS2 standards ask you to evaluate evidence about how human activities affect ecosystems and biodiversity, and how conservation can reduce the harm. For the Biology I EOC that means knowing the major human impacts (habitat destruction, pollution, climate change, invasive species, overharvesting), being able to explain their effects (such as how greenhouse gases drive climate change), and being able to suggest conservation strategies. Items often pair a cause with a consequence and ask for a solution.

The major human impacts

These pressures often combine and reinforce one another, and the EOC may ask you to identify which is the leading cause (habitat destruction) or to match a description to the right impact.

Climate change and the carbon connection

Burning fossil fuels (coal, oil, gas) releases carbon dioxide into the atmosphere, adding to the carbon cycle far faster than natural processes remove it. Carbon dioxide is a greenhouse gas: it traps heat in the atmosphere, so increasing its concentration raises global temperatures, which is climate change. The effects on ecosystems include shifting habitats and ranges, changing the timing of seasonal events, melting ice, rising sea levels, and warming and acidifying oceans (which harms coral reefs). This directly links human activity to the cycling of matter, where photosynthesis and respiration normally balance atmospheric carbon.

Effects on biodiversity and stability

Because these impacts reduce biodiversity, they also reduce ecosystem stability and resilience. A simpler ecosystem (fewer species) is more fragile and recovers less well from disturbance. Loss of biodiversity also reduces the benefits ecosystems provide to humans (food, medicines, clean water, pollination), so the standard treats human impact and conservation as a matter of both ecological and human importance.

Conservation: reducing the impact

The flip side of the standard is conservation, the strategies that reduce harm and protect ecosystems:

• Protect habitats: nature reserves, national parks, and wildlife corridors.
• Reduce pollution: limit emissions, treat waste, and reduce single-use materials.
• Reduce fossil-fuel use and shift to renewable energy (solar, wind) to slow climate change.
• Recycle and reduce consumption to lower resource demand.
• Restore damaged ecosystems (replanting forests, restoring wetlands).
• Manage resources sustainably, such as fishing and logging within limits that let populations recover.

An EOC item may ask you to evaluate a strategy or pair a problem with a solution, so be ready to give a concrete conservation measure for a given impact.

Try this

Q1. State the leading cause of species becoming endangered or extinct and explain why it has such a large effect. [2]

• Cue. Habitat destruction; it removes the place organisms live, feed, and reproduce, so their populations decline or disappear.

Q2. Explain how burning fossil fuels contributes to climate change. [2]

• Cue. It releases carbon dioxide, a greenhouse gas, into the atmosphere; the extra carbon dioxide traps more heat, raising global temperatures, which is climate change.