Environment

Correct answer: A

I is incorrect: Biochemical oxygen demand → Oxygen consumed by biological decomposition under specified conditions. High BOD often indicates substantial biodegradable organic pollution. II is incorrect: Primary pollutant → Released directly from a source. Carbon monoxide from incomplete combustion is an example.

Correct answer: C

It may impair communication, sleep or hearing.

Correct answer: D

I is correct: Chemical oxygen demand → Oxygen equivalent needed for chemical oxidation in a test. COD measures a wider set of oxidisable materials than BOD. II is correct: Acid rain → Deposition made unusually acidic by pollutants such as sulphur and nitrogen oxides. Acid-forming reactions occur in the atmosphere.

Correct answer: A

I is correct: Primary pollutant → Released directly from a source. Carbon monoxide from incomplete combustion is an example. II is incorrect: Photochemical smog → Pollution produced by sunlight-driven reactions involving precursor gases. Nitrogen oxides and volatile organic compounds are important precursors.

Correct answer: B

Persistent substances can reach high levels in top consumers.

Correct answer: D

I is incorrect: Noise pollution → Unwanted sound with adverse effects. It may impair communication, sleep or hearing. II is incorrect: Secondary pollutant → Formed through reactions after emission. Ground-level ozone is a major example.

Correct answer: C

Uptake exceeds elimination.

Correct answer: B

I is incorrect: Biochemical oxygen demand → Oxygen consumed by biological decomposition under specified conditions. High BOD often indicates substantial biodegradable organic pollution. II is incorrect: Leachate → Contaminated liquid draining through waste. Uncontrolled leachate can pollute soil and groundwater.

Correct answer: A

Ground-level ozone is a major example.

Correct answer: C

I is incorrect: Acid rain → Deposition made unusually acidic by pollutants such as sulphur and nitrogen oxides. Acid-forming reactions occur in the atmosphere. II is correct: Photochemical smog → Pollution produced by sunlight-driven reactions involving precursor gases. Nitrogen oxides and volatile organic compounds are important precursors.

Correct answer: A

I is correct: Primary pollutant → Released directly from a source. Carbon monoxide from incomplete combustion is an example. II is incorrect: Leachate → Contaminated liquid draining through waste. Uncontrolled leachate can pollute soil and groundwater.

Correct answer: D

Severe depletion can harm fish and other aerobic life.

Correct answer: C

I is incorrect: Leachate → Contaminated liquid draining through waste. Uncontrolled leachate can pollute soil and groundwater. II is correct: Noise pollution → Unwanted sound with adverse effects. It may impair communication, sleep or hearing.

Correct answer: B

Carbon monoxide from incomplete combustion is an example.

Correct answer: A

I is incorrect: PM2.5 → Airborne particles with aerodynamic diameter at most 2.5 micrometres. Fine particles can penetrate deeply into the respiratory tract. II is incorrect: Biochemical oxygen demand → Oxygen consumed by biological decomposition under specified conditions. High BOD often indicates substantial biodegradable organic pollution.

Correct answer: A

Fine particles can penetrate deeply into the respiratory tract.

Correct answer: A

I is incorrect: Chemical oxygen demand → Oxygen equivalent needed for chemical oxidation in a test. COD measures a wider set of oxidisable materials than BOD. II is correct: Primary pollutant → Released directly from a source. Carbon monoxide from incomplete combustion is an example.

Correct answer: B

I is incorrect: One partner benefits while the other is neither helped nor harmed → Commensalism. The second species has approximately neutral effects in the simplified model. II is correct: Both partners benefit in a persistent biological association → Mutualism. Both species obtain a net benefit.

Correct answer: C

I is incorrect: Species whose habitat protection also shelters many others → Umbrella species. Large or diverse habitat needs can encompass other species. II is incorrect: Fungus exchanging nutrients with plant roots → Mycorrhizal mutualism. Fungi can improve nutrient uptake in return for plant carbon.

Correct answer: D

Plant tissue is consumed by an animal.

Correct answer: C

I is incorrect: Species chosen to represent a conservation campaign → Flagship species. Public appeal can support broader conservation action. II is incorrect: Species used to infer environmental conditions → Indicator species. Its presence or condition can reveal habitat quality.

Correct answer: D

One is harmed and the other is approximately unaffected.

Correct answer: C

I is incorrect: Species with a disproportionately large effect on community structure → Keystone species. Its influence exceeds what abundance alone would predict. II is incorrect: One partner benefits while the other is neither helped nor harmed → Commensalism. The second species has approximately neutral effects in the simplified model.

Correct answer: D

Fungi can improve nutrient uptake in return for plant carbon.

Correct answer: A

I is correct: Both partners benefit in a persistent biological association → Mutualism. Both species obtain a net benefit. II is incorrect: Grazing animal feeding on plants → Herbivory. Plant tissue is consumed by an animal.