Environmental Science Study Guide 2026

Everything you need to pass the Environmental Science exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.

📋 Environmental Science Exam Format at a Glance

80
Questions
90 min
Time Limit
65.00%
Passing Score

📚 Environmental Science Topics to Study (39)

✍️ Sample Environmental Science Questions & Answers

1. What is a carbon sink?
A natural or artificial reservoir that absorbs more carbon than it releases

Carbon sinks like forests and oceans absorb net CO₂ from the atmosphere, helping regulate atmospheric carbon levels.

2. Which of the following is a primary environmental concern associated with utility-scale solar PV installations?
Land use impacts and habitat disruption in desert ecosystems, plus waste from end-of-life panel disposal

Large solar farms require significant land area (5-10 acres/MW), potentially displacing desert tortoises, plant communities, and other sensitive species; end-of-life panels contain cadmium, lead, and other materials requiring careful disposal.

3. Genetically modified (GM) crops engineered with Bt toxin produce an insecticide that:
Is derived from a naturally occurring soil bacterium and is toxic to specific insect larvae

Bt toxin is derived from Bacillus thuringiensis, a naturally occurring soil bacterium; its crystal proteins are highly selective, primarily toxic to Lepidoptera (caterpillars) or Coleoptera (beetles) larvae, not to mammals or most non-target organisms.

4. Which class of air pollutants is regulated under the U.S. Clean Air Act as the six common air pollutants?
Criteria air pollutants

The EPA designates six 'criteria pollutants' including ozone, particulate matter, CO, NO₂, SO₂, and lead.

5. Which U.S. law provides the primary legal framework for protecting threatened and endangered species and their habitats?
Endangered Species Act (ESA)

The Endangered Species Act (1973) prohibits harm to listed species and requires recovery plans and critical habitat designation.

6. What is a lahar, and which natural disaster is it most directly associated with?
A mudflow of volcanic debris and water associated with volcanic eruptions

A lahar is a fast-moving mudflow or debris flow composed of a mixture of volcanic material and water that travels down the slopes of a volcano.

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Your Environmental Science Study Path
1. Learn with Flashcards → 2. Drill Practice Tests → 3. Take the Full Exam Simulation