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Introduction to Environmental Science and Ecology — HS Environmental Science practice questions

28 multiple-choice questions and 20 flashcards on Introduction to Environmental Science and Ecology, about 19% of the HS Environmental Science bank. Every one carries a written rationale.

Written and maintained by Nick Burton · last updated 2026-08-22 · how we write and review questions

What this chapter covers

Introduction to Environmental Science and Ecology is one of 11 chapters in CoStudy's HS Environmental Science bank, and it holds 28 of the bank's 150 multiple-choice questions — roughly 19% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.

Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.

Free Introduction to Environmental Science and Ecology practice questions

7 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.

An ecosystem consists of:

  1. Only the living organisms in an area
  2. Only the non-living components of an area
  3. All living organisms and their physical environment interacting as a system
  4. A single species and its predators

Answer: C — All living organisms and their physical environment interacting as a system

An ecosystem includes both biotic (living) and abiotic (non-living) components and their interactions.

Biomagnification refers to:

  1. The growth of a population over generations
  2. The reproduction of magnifying organisms
  3. The increasing concentration of toxins (e.g., mercury, DDT) up trophic levels in a food chain
  4. The reduction of toxins in higher organisms

Answer: C — The increasing concentration of toxins (e.g., mercury, DDT) up trophic levels in a food chain

Persistent toxins accumulate in tissues and concentrate up food chains. Apex predators (e.g., tuna, eagles) often have the highest contaminant levels.

Acid rain is most commonly caused by:

  1. Methane emissions from livestock
  2. Sulfur dioxide and nitrogen oxide emissions reacting with water in the atmosphere
  3. Carbon dioxide alone
  4. Volcanic ash

Answer: B — Sulfur dioxide and nitrogen oxide emissions reacting with water in the atmosphere

SO₂ and NOₓ emissions (mainly from burning coal and vehicle exhaust) react with atmospheric water to form sulfuric and nitric acids.

Primary succession occurs when:

  1. A forest grows back after a fire
  2. An ecosystem develops on previously lifeless substrate (e.g., bare rock after a glacier retreats)
  3. Crops grow in farmland
  4. An invasive species takes over

Answer: B — An ecosystem develops on previously lifeless substrate (e.g., bare rock after a glacier retreats)

Primary succession starts from bare rock or new volcanic land; secondary succession occurs where soil already exists (e.g., after fire).

Sustainable development is best defined as:

  1. Economic growth with no environmental considerations
  2. Development that meets present needs without compromising future generations' ability to meet theirs
  3. Halting all development to protect nature
  4. Building only renewable-energy infrastructure

Answer: B — Development that meets present needs without compromising future generations' ability to meet theirs

The Brundtland definition (1987) emphasizes balancing economic, social, and environmental needs across generations.

The IPCC (Intergovernmental Panel on Climate Change) is best known for:

  1. Setting binding climate targets for every nation
  2. Conducting original climate experiments
  3. Synthesizing peer-reviewed climate science to inform policymakers
  4. Funding renewable energy projects

Answer: C — Synthesizing peer-reviewed climate science to inform policymakers

The IPCC, a UN body, assesses and synthesizes climate research to produce authoritative reports for governments — it does not conduct original research.

The carbon cycle moves carbon between:

  1. Only the atmosphere and plants
  2. The atmosphere, biosphere, hydrosphere, and lithosphere
  3. Only soil and oceans
  4. Only living organisms

Answer: B — The atmosphere, biosphere, hydrosphere, and lithosphere

Carbon cycles through atmosphere (CO₂), biosphere (organisms), hydrosphere (dissolved CO₂ in oceans), and lithosphere (rocks, fossil fuels).

Introduction to Environmental Science and Ecology flashcards

4 cards from the 20 in this chapter.

Decomposer?

Bacteria, fungi. Break down dead matter, return nutrients to soil.

Ecosystem?

Community of organisms + their physical environment, interacting.

Invasive species?

Non-native species causing harm. No natural predators. Often outcompete natives.

Biome?

Large region with characteristic climate + community.

Practise the full chapter

These are a sample. The full Introduction to Environmental Science and Ecology chapter runs 48 items with per-chapter progress tracking, on the web and in the iOS app.

Open HS Environmental Science in CoStudy →

Other HS Environmental Science chapters

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