Noesis
Level 1 — RecognitionConservation & Human Impact

Conservation & Human Impact

⏱ 20 minutes30 marksprintable — key stays hidden on paper

Level 1: Recognition Test

Time Limit: 20 minutes Total Marks: 30

Section A — Multiple Choice (1 mark each)

Choose the single best answer.

Q1. Which of the following is the leading direct cause of biodiversity loss worldwide?

  • A) Ozone depletion
  • B) Habitat destruction
  • C) Volcanic eruptions
  • D) Increased rainfall

Q2. Biomagnification refers to the:

  • A) Breakdown of pollutants by decomposers
  • B) Increasing concentration of a toxin in tissues along a food chain
  • C) Dilution of toxins in the ocean
  • D) Rapid growth of algae in a lake

Q3. Which gas is the principal contributor to the enhanced greenhouse effect from fossil fuel combustion?

  • A) Oxygen
  • B) Nitrogen
  • C) Carbon dioxide
  • D) Argon

Q4. Eutrophication of a lake is most directly triggered by:

  • A) Excess nitrates and phosphates entering the water
  • B) A drop in water temperature
  • C) Removal of predatory fish
  • D) Increased dissolved oxygen

Q5. The chemicals mainly responsible for ozone layer depletion are:

  • A) Carbon dioxide
  • B) Chlorofluorocarbons (CFCs)
  • C) Methane
  • D) Sulphur dioxide

Q6. An ex situ conservation strategy is:

  • A) A national park
  • B) A protected marine reserve
  • C) A seed bank / botanical garden
  • D) A wildlife corridor

Q7. Habitat fragmentation typically leads to:

  • A) Larger, more connected populations
  • B) Smaller, isolated populations with reduced gene flow
  • C) Increased genetic diversity
  • D) Elimination of edge effects

Q8. An invasive species often thrives in a new habitat because it:

  • A) Has natural predators present
  • B) Lacks natural predators and competitors
  • C) Cannot reproduce quickly
  • D) Requires very specific conditions

Q9. Sustainable resource management aims to:

  • A) Maximise short-term profit only
  • B) Use resources at a rate that allows replenishment for future generations
  • C) Prevent all human use of resources
  • D) Increase pollutant discharge

Q10. Which best describes bioaccumulation?

  • A) Toxin build-up within a single organism over its lifetime
  • B) Toxin transfer between trophic levels
  • C) Loss of toxins through excretion
  • D) Breakdown of DDT by sunlight

Section B — Matching (1 mark each, 5 marks total)

Q11–Q15. Match each term (left) to its correct description (right). Write the letter.

Term Description
Q11. Deforestation A. Nutrient enrichment causing algal blooms and oxygen depletion
Q12. Eutrophication B. Bands of habitat linking fragmented areas
Q13. Wildlife corridor C. Removal of forest cover reducing habitat
Q14. Keystone species D. Species whose removal drastically alters an ecosystem
Q15. UV radiation increase E. Consequence of ozone layer thinning

Section C — True/False with Justification (3 marks each, 15 marks total)

State True or False (1 mark) and justify your answer in one sentence (2 marks).

Q16. "Global warming is caused by ozone depletion." — True or False? Justify.

Q17. "Persistent, fat-soluble toxins like DDT are most concentrated in top predators." — True or False? Justify.

Q18. "Habitat fragmentation increases the amount of edge habitat relative to interior habitat." — True or False? Justify.

Q19. "Introducing an invasive species always increases the biodiversity of an ecosystem." — True or False? Justify.

Q20. "Eutrophication ultimately increases dissolved oxygen available to fish." — True or False? Justify.

END OF PAPER

Answer keyMark scheme & solutions

Section A — MCQ (1 mark each)

Q1. B — Habitat destruction/loss is the single largest driver of species extinction globally. (1)

Q2. B — Biomagnification = increasing toxin concentration at successive trophic levels. (1)

Q3. C — CO₂ from fossil fuel burning is the dominant anthropogenic greenhouse gas. (1)

Q4. A — Nitrate/phosphate enrichment (fertiliser runoff) drives eutrophication. (1)

Q5. B — CFCs release chlorine radicals that catalytically destroy ozone. (1)

Q6. C — Seed banks conserve organisms outside their natural habitat (ex situ). Options A, B, D are in situ. (1)

Q7. B — Fragmentation isolates populations, reducing gene flow. (1)

Q8. B — Absence of natural predators/competitors allows unchecked spread. (1)

Q9. B — Sustainability = use at a replenishable rate for future generations. (1)

Q10. A — Bioaccumulation is build-up within one organism over time (vs. biomagnification across trophic levels). (1)

Section B — Matching (1 mark each)

Q11 → C (Deforestation = removal of forest cover) (1) Q12 → A (Eutrophication = nutrient enrichment → algal bloom → O₂ depletion) (1) Q13 → B (Wildlife corridor links fragmented habitats) (1) Q14 → D (Keystone species removal drastically alters ecosystem) (1) Q15 → E (Ozone thinning → more UV reaching surface) (1)

Section C — True/False with Justification (3 marks each)

Q16. FALSE (1). Justification: Global warming is caused by greenhouse gases (mainly CO₂, CH₄) trapping heat; ozone depletion is a separate problem caused by CFCs that increases UV exposure — the two are distinct processes. (2)

Q17. TRUE (1). Justification: Fat-soluble, non-degradable toxins are not excreted and biomagnify up the food chain, so they reach highest concentrations in top predators. (2)

Q18. TRUE (1). Justification: Breaking a large habitat into smaller pieces increases the perimeter-to-area ratio, exposing more edge and less protected interior habitat. (2)

Q19. FALSE (1). Justification: Invasive species typically outcompete or prey on native species, often reducing native biodiversity rather than increasing overall diversity. (2)

Q20. FALSE (1). Justification: Algal blooms die and are decomposed by bacteria that consume oxygen, decreasing dissolved oxygen (hypoxia) and killing fish. (2)

Mark Distribution

  • Section A: 10 marks
  • Section B: 5 marks
  • Section C: 15 marks
  • Total: 30 marks
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  {"claim": "Section B matching totals 5 marks", "code": "items = 5; marks = items*1; result = (marks == 5)"},
  {"claim": "Section C: 5 questions at 3 marks = 15 marks", "code": "q = 5; per = 3; result = (q*per == 15)"},
  {"claim": "Overall paper totals 30 marks", "code": "total = 10 + 5 + 5*3; result = (total == 30)"},
  {"claim": "Total question count is 20", "code": "count = 10 + 5 + 5; result = (count == 20)"}
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