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1.7 Ecosystem — Test 1
Q1. In a shallow lentic (standing-water) habitat, which zone is the most productive?✓ Littoral
Q2. A 'static' food web primarily depicts:✓ Presence/absence of interactions
Q3. Which function do insects directly perform in many ecosystems?✓ Pollination
Q4. Food webs based on the impact of species on the structure of a community are called:✓ Functional food webs
Q5. An assemblage of populations of plants, animals, bacteria and fungi living in an area and interacting is defined as a:✓ Biological community
Q6. All individuals of a single species inhabiting a given area constitute a:✓ Population
Q7. What is considered the ultimate function of any ecosystem?✓ Flow of energy
Q8. Which ecosystem has the LOWEST net primary productivity per unit area?✓ Open ocean
Q9. The phosphorus cycle is unusual among nutrient cycles in that it is essentially:✓ Sedimentary (no gaseous phase)
Q10. The pyramid of biomass is:✓ Usually upright but can be inverted in some aquatic systems
Q11. A pond ecosystem with phytoplankton producers is often characterised by an:✓ Inverted pyramid of biomass
Q12. In an ecosystem, which trophic level captures and makes available the maximum total energy?✓ Primary producers
Q13. Food webs based on 'who eats whom', emphasising feeding relationships, are called:✓ Connectedness webs
Q14. The pyramid of energy (productivity) in an ecosystem is always:✓ Upright
1.7 Ecosystem — Test 2
Q15. Which biogeochemical cycle is called a sedimentary cycle because its main reservoir is sedimentary rock?✓ Phosphorus cycle
Q16. Phosphate is made available to the biotic components of an ecosystem mainly from:✓ Rocks and soil
Q17. The Redfield ratio describes the relatively constant atomic ratio in marine plankton of:✓ Carbon, nitrogen and phosphorus
Q18. In a pond ecosystem, the deep bottom region where respiration exceeds production is the:✓ Profundal zone
Q19. Which of the following would NOT qualify as an ecosystem service?✓ Rainfall to earth
Q20. In a pelagic (open-water) food web, a major pathway for organic-matter flux is the:✓ Microbial loop
Q21. The most abundant gas reservoir cycled in similar magnitude through atmosphere and lithosphere belongs to the:✓ Sulphur cycle
Q22. In which marine zone is plankton most abundant?✓ Neritic zone
Q23. Which group does NOT contribute to primary productivity in a marine ecosystem?✓ Molluscs and crustaceans
Q24. An ecosystem free of stress tends to be:✓ Highly diverse and stable
Q25. Which ecosystem is most likely to show an inverted pyramid of biomass?✓ Pond
Q26. The principle of a holocoenotic environment means that:✓ Every factor affects every other factor in an ecosystem
Q27. The term 'ecosystem' and its energy-trophic dynamics were notably quantified by:✓ Raymond Lindeman
Q28. Secondary productivity in an ecosystem is the rate at which:✓ Consumers convert organic matter into their own biomass
1.7 Ecosystem — Test 3
Q29. Biological magnification (biomagnification) refers to the:✓ Accumulation of toxins at higher trophic levels
Q30. A lake rich in nutrients and supporting dense algal growth is classified as:✓ Eutrophic
Q31. Which of the following is a correct grazing food chain?✓ Phytoplankton → zooplankton → fish → bird
Q32. The best example of a man-made (artificial) ecosystem is a(n):✓ Aquarium
Q33. Trophic levels in an ecosystem are formed by:✓ Organisms linked in a food chain
Q34. Which ecological pyramid is always upright (never inverted)?✓ Pyramid of energy
Q35. The phosphorus cycle differs from the carbon and nitrogen cycles mainly because phosphorus:✓ Has no atmospheric (gaseous) phase
Q36. The key difference between a food chain and a food web is that a:✓ Food chain is a single linear pathway while a food web is interconnected
Q37. A lake rich in minerals and organic nutrients, promoting phytoplankton but low in oxygen, is termed:✓ Eutrophic
Q38. Some aquatic ecosystems show an inverted biomass pyramid mainly because of:✓ High turnover of small aquatic producers relative to consumers
Q39. Consumption (utilization) efficiency of herbivores is typically highest in:✓ Managed grasslands
Q40. Which statement about ecosystem energetics is NOT correct?✓ Production efficiency of carnivores is higher than that of herbivores
Q41. Which feature is most likely to contribute to the stability of an ecosystem?✓ More omnivores (reticulate food web)
Q42. A greater proportion of autotroph-fixed energy reaches herbivores in the open ocean than in a forest because:✓ Terrestrial autotrophs have more indigestible tissues
1.7 Ecosystem — Test 4
Q43. Regarding energy efficiencies: ectotherms have high assimilation but low production efficiency, while endotherms have low assimilation but high production efficiency? The correct pairing is:✓ Ectotherms: low assimilation, high production efficiency; Endotherms: high assimilation, low production efficiency
Q44. In which ecosystem does autotroph-fixed energy reach the primary carnivore level in the SHORTEST time?✓ Ocean
Q45. The significance of an upwelling zone for marine ecosystems is that it:✓ Brings deep nutrients to the surface, raising productivity
Q46. The most common method of estimating primary productivity of a pond measures the amount of:✓ Oxygen released
Q47. Which sequence lists ecosystems in INCREASING order of plant productivity per unit leaf area?✓ Hot deserts, temperate grasslands, tropical forests
Q48. In a lake with phytoplankton, zooplankton and planktivorous fish, introducing a piscivorous (fish-eating) fish will, by top-down control, cause:✓ Zooplankton to rise and phytoplankton to fall
Q49. Lindeman's efficiency between two trophic levels is calculated as:✓ Assimilation at level n ÷ assimilation at level n−1
Q50. In which ecosystem is the detritus (detrital) pathway of energy flow most important?✓ Tropical rainforest
Q51. The periodic backward movement of warm surface water toward the tropical eastern Pacific is known as:✓ El Niño
Q52. Which trophic relationship results in an inverted pyramid of numbers?✓ A single large tree supporting many insects
Q53. Which one of the following is a correct detritus food chain?✓ Fallen leaves → bacteria → insect → frog
Q54. Gross primary productivity (GPP) minus the respiration of producers equals:✓ Net primary productivity (NPP)
Q55. According to Lindeman's ten-percent law, energy passed from one trophic level to the next is about:✓ 10%