The Function of an Ecosystem MCQs With Answer offers B. Pharm students a focused review of ecosystem functions, ecological processes, and ecosystem services that directly influence pharmacognosy, drug discovery, and environmental pharmacology. This compact, keyword-rich guide emphasizes nutrient cycling, primary productivity, decomposition, pollination, habitat provision, and microbial roles in producing bioactive compounds — all essential for understanding medicinal plant ecology and sustainable harvesting. Each question links ecological concepts to pharmaceutical relevance, such as biogeochemical cycles, bioaccumulation, and ecosystem services that affect drug resource availability and quality. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which of the following best describes the primary function of an ecosystem?
- Manufacturing of synthetic drugs
- Maintenance of ecological processes that support life
- Providing unlimited natural resources
- Elimination of all pathogens
Correct Answer: Maintenance of ecological processes that support life
Q2. Which ecosystem function directly supports growth of medicinal plants by recycling nutrients?
- Primary productivity
- Decomposition
- Pollination
- Habitat fragmentation
Correct Answer: Decomposition
Q3. What term describes the total amount of organic matter produced by photosynthesis in an ecosystem?
- Net primary productivity (NPP)
- Gross primary productivity (GPP)
- Secondary productivity
- Biomagnification
Correct Answer: Gross primary productivity (GPP)
Q4. Which of the following is a regulating ecosystem service relevant to pharmaceutical quality?
- Genetic resources
- Climate regulation and pollutant breakdown
- Recreation and tourism
- Timber production
Correct Answer: Climate regulation and pollutant breakdown
Q5. Which biogeochemical cycle is most directly involved in formation of amino acids required for secondary metabolite synthesis?
- Carbon cycle
- Nitrogen cycle
- Phosphorus cycle
- Sulfur cycle
Correct Answer: Nitrogen cycle
Q6. Which organism group is most important in nitrogen fixation that benefits medicinal plants?
- Herbivores
- Rhizobial bacteria and cyanobacteria
- Fungi causing rot
- Arthropod pollinators
Correct Answer: Rhizobial bacteria and cyanobacteria
Q7. Which function of wetlands is most relevant for removing pharmaceutical pollutants from water?
- Carbon sequestration
- Water filtration and contaminant biodegradation
- Providing urban aesthetic value
- Supporting commercial fisheries only
Correct Answer: Water filtration and contaminant biodegradation
Q8. What is the approximate trophic transfer efficiency between trophic levels in many ecosystems?
- 90%
- 50%
- 10%
- 1%
Correct Answer: 10%
Q9. Which term refers to species that have a disproportionately large effect on ecosystem structure?
- Indicator species
- Keystone species
- Invasive species
- Dominant species
Correct Answer: Keystone species
Q10. Which ecosystem process directly influences secondary metabolite profiles in medicinal plants?
- Soil nutrient availability and microbial interactions
- Number of tourists visiting the habitat
- Distance from urban centers only
- Altitude irrespective of soil or microbes
Correct Answer: Soil nutrient availability and microbial interactions
Q11. Which category of ecosystem services includes provision of raw materials used in drug discovery?
- Regulating services
- Provisioning services
- Cultural services
- Supporting services
Correct Answer: Provisioning services
Q12. What role do decomposers play that is essential for plant-based pharmaceutical production?
- They fix carbon via photosynthesis
- They break down organic matter releasing nutrients
- They pollinate flowering plants
- They act as primary consumers
Correct Answer: They break down organic matter releasing nutrients
Q13. Which process explains gradual increase in soil fertility through leaf litter breakdown?
- Succession
- Decomposition and humification
- Erosion
- Abiotic weathering only
Correct Answer: Decomposition and humification
Q14. Bioaccumulation of persistent pollutants in medicinal plants is most likely to affect which pharmaceutical concern?
- Therapeutic potency
- Drug formulation techniques
- Safety and toxicity of plant-derived medicines
- Tablet dissolution rates in vitro
Correct Answer: Safety and toxicity of plant-derived medicines
Q15. Which of the following best defines an ecological niche?
- The physical place a species occupies
- All interactions and roles a species has in an ecosystem
- The genetic makeup of a species
- The population size of a species
Correct Answer: All interactions and roles a species has in an ecosystem
Q16. Which microbial genus is well-known for producing many antibiotics used in medicine?
- Escherichia
- Streptomyces
- Clostridium
- Rickettsia
Correct Answer: Streptomyces
Q17. What is the main ecological consequence of habitat fragmentation for medicinal plant populations?
- Increased genetic diversity
- Reduced gene flow and smaller isolated populations
- Immediate increase in primary productivity
- Enhanced pollinator abundance everywhere
Correct Answer: Reduced gene flow and smaller isolated populations
Q18. Which term describes the network of feeding relationships in an ecosystem?
- Trophic cascade
- Food web
- Biogeochemical loop
- Symbiotic matrix
Correct Answer: Food web
Q19. Which ecosystem process most directly affects availability of phosphorus for plant secondary metabolism?
- Atmospheric nitrogen fixation
- Weathering of rocks and soil mineralization
- Photosynthetic rate of algae
- Animal grazing intensity
Correct Answer: Weathering of rocks and soil mineralization
Q20. What is an example of a supporting ecosystem service relevant to drug discovery?
- Pollination
- Soil formation and nutrient cycling
- Commercial fishing
- Oil extraction
Correct Answer: Soil formation and nutrient cycling
Q21. Which ecological measure indicates resilience of an ecosystem to disturbances?
- Rate of succession only
- Ability to return to original state after disturbance
- Number of invasive species present
- Height of dominant trees
Correct Answer: Ability to return to original state after disturbance
Q22. Which process contributes to biomagnification of lipophilic drugs in food chains?
- High metabolic breakdown in predators
- Accumulation of lipophilic compounds in fatty tissues
- Rapid excretion by herbivores
- Dilution at each trophic level
Correct Answer: Accumulation of lipophilic compounds in fatty tissues
Q23. Which ecosystem service is most directly linked to traditional medicine practices?
- Supporting services only
- Provisioning of medicinal plants
- Climate regulation exclusively
- Noise reduction
Correct Answer: Provisioning of medicinal plants
Q24. Which factor increases production of secondary metabolites in plants used as drugs?
- Low stress and uniform conditions
- Environmental stresses like herbivory or drought
- High levels of pollutants only
- Lack of microbial interactions
Correct Answer: Environmental stresses like herbivory or drought
Q25. What is the primary source of energy driving most terrestrial ecosystems?
- Chemical energy from rocks
- Solar radiation converted by photosynthesis
- Geothermal heat
- Wind energy
Correct Answer: Solar radiation converted by photosynthesis
Q26. Which term refers to ecosystems engineered by organisms that alter habitat structure?
- Keystone species
- Ecosystem engineers
- Autotrophs
- Decomposers
Correct Answer: Ecosystem engineers
Q27. How do pollinators indirectly support pharmaceutical industries?
- By reducing soil fertility
- By facilitating reproduction of medicinal plants
- By increasing herbivore populations
- By causing plant diseases
Correct Answer: By facilitating reproduction of medicinal plants
Q28. Which of the following best describes an indicator species?
- A species used to indicate environmental conditions or ecosystem health
- A species with the largest population size
- A species that is always invasive
- A species that provides maximum biomass
Correct Answer: A species used to indicate environmental conditions or ecosystem health
Q29. What is the effect of soil microbiome diversity on plant-based drug yields?
- No effect at all
- It can enhance nutrient uptake and secondary metabolite production
- It always reduces drug compound concentrations
- It only affects root architecture, not chemistry
Correct Answer: It can enhance nutrient uptake and secondary metabolite production
Q30. What term describes gradual replacement of one community by another over time?
- Ecological succession
- Genetic drift
- Biomagnification
- Primary production
Correct Answer: Ecological succession
Q31. Which process is essential for recycling sulfur needed in some plant metabolites?
- Sulfur cycle involving microbial transformations
- Photosynthesis in plants
- Physical erosion only
- Atmospheric nitrogen deposition only
Correct Answer: Sulfur cycle involving microbial transformations
Q32. Which ecosystem change most threatens long-term supply of medicinal plants?
- Sustainable harvesting practices
- Habitat loss and land-use change
- Community-based conservation
- Soil restoration
Correct Answer: Habitat loss and land-use change
Q33. What is ecological stoichiometry important for in pharmaceutical plant cultivation?
- Balancing nutrient ratios affecting growth and metabolite synthesis
- Measuring leaf color only
- Calculating herbivore numbers
- Predicting atmospheric oxygen levels
Correct Answer: Balancing nutrient ratios affecting growth and metabolite synthesis
Q34. Which ecosystem service is provided by microbes that convert organic matter into bioactive compounds?
- Cultural services
- Provisioning of genetic resources and bioactive molecules
- Scenic beauty
- Noise buffering
Correct Answer: Provisioning of genetic resources and bioactive molecules
Q35. Which human activity most directly increases risk of bioaccumulation in medicinal food chains?
- Selective breeding of plants
- Release of persistent organic pollutants and heavy metals
- Sustainable agroforestry
- Organic composting
Correct Answer: Release of persistent organic pollutants and heavy metals
Q36. Which ecological metric assesses living biomass produced per unit area per time?
- Productivity (primary productivity)
- Species richness only
- Habitat heterogeneity
- Evapotranspiration rate exclusively
Correct Answer: Productivity (primary productivity)
Q37. Which interaction between plants and microbes is crucial for many medicinal compound pathways?
- Parasitism only
- Mutualistic symbioses like mycorrhizae
- Neutralism only
- Predation of microbes by plants
Correct Answer: Mutualistic symbioses like mycorrhizae
Q38. Which factor most directly causes shifts in phenology, affecting drug harvest times?
- Climate change and temperature shifts
- Soil texture only
- Herbivore population decline only
- Geological uplift
Correct Answer: Climate change and temperature shifts
Q39. What is the detritus food chain primarily based on?
- Live plant consumption by herbivores
- Decomposition of dead organic material
- Direct solar energy consumption by animals
- Mineral mining
Correct Answer: Decomposition of dead organic material
Q40. Which approach helps conserve medicinal plant diversity while supporting drug research?
- Unregulated wild harvesting
- Combining in situ conservation and sustainable cultivation
- Monoculture plantations with heavy pesticides
- Complete prohibition of all harvesting
Correct Answer: Combining in situ conservation and sustainable cultivation
Q41. Which concept explains why loss of a top predator can alter vegetation and medicinal plant communities?
- Trophic cascade
- Primary succession
- Ecological stoichiometry
- Photoperiodism
Correct Answer: Trophic cascade
Q42. Which is a direct measure of soil health relevant to plant-based drug production?
- Microbial biomass and activity
- Number of roads nearby
- Height of the tallest tree only
- Volume of nearby lakes regardless of quality
Correct Answer: Microbial biomass and activity
Q43. Which ecosystem component stores the largest pool of terrestrial carbon?
- Atmospheric CO2
- Soil organic matter and vegetation combined
- Surface water only
- Human-made structures
Correct Answer: Soil organic matter and vegetation combined
Q44. How can ecological restoration improve pharmaceutical resources?
- By reducing biodiversity to increase target species
- By restoring habitat, increasing plant populations and genetic diversity
- By introducing synthetic chemicals into the soil
- By converting forests to paved surfaces
Correct Answer: By restoring habitat, increasing plant populations and genetic diversity
Q45. Which process describes movement of elements through living organisms and environment?
- Trophic transfer only
- Biogeochemical cycles
- Population dynamics exclusively
- Limiting nutrient theory only
Correct Answer: Biogeochemical cycles
Q46. Which human intervention can reduce pharmaceutical contamination in aquatic ecosystems?
- Discharging untreated effluents
- Improved wastewater treatment and pharmaceutical take-back programs
- Increasing pesticide usage
- Draining wetlands for development
Correct Answer: Improved wastewater treatment and pharmaceutical take-back programs
Q47. Which ecosystem attribute enhances chances of discovering novel drug leads?
- Low habitat heterogeneity
- High biodiversity and unique ecological niches
- Monoculture agricultural systems
- Urbanized landscapes only
Correct Answer: High biodiversity and unique ecological niches
Q48. Which term refers to the human benefit derived from pollination, seed dispersal, and nutrient cycling?
- Cultural ecosystem services
- Provisioning services exclusively
- Ecosystem services
- Geological services
Correct Answer: Ecosystem services
Q49. In the context of ecosystems and pharmacology, what is “pharmacognosy” primarily concerned with?
- Synthetic drug manufacturing only
- Study of medicinal drugs from natural sources and their ecological origins
- Analysis of drug patents exclusively
- Pharmacokinetics in humans only
Correct Answer: Study of medicinal drugs from natural sources and their ecological origins
Q50. Which monitoring tool helps assess ecosystem health relevant to medicinal plant conservation?
- Indicator species surveys and habitat quality assessments
- Counting only vehicles near habitats
- Measuring only atmospheric pressure
- Tracking weather forecasts exclusively
Correct Answer: Indicator species surveys and habitat quality assessments
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