Forest ecosystem – structure and function MCQs With Answer offers B.Pharm students a concise, exam-focused review of forest ecology fundamentals relevant to pharmacognosy, biodiversity conservation, and sustainable sourcing of medicinal plants. This introduction highlights key concepts: biotic and abiotic components, trophic levels, nutrient cycling, primary productivity, decomposition, mycorrhizal associations, and ecosystem services such as provisioning of medicinal resources and regulation of water and climate. Emphasis on structure-function relationships helps students link ecological processes to drug discovery, phytochemistry, and environmental impacts on pharmaceuticals. Clear, keyword-rich content supports revision and concept retention. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which component of a forest ecosystem primarily determines energy flow through trophic levels?
- Decomposers
- Producers (green plants)
- Top predators
- Soil microorganisms
Correct Answer: Producers (green plants)
Q2. What term describes the variety and variability of life forms in a forest, important for medicinal plant discovery?
- Productivity
- Resistance
- Biodiversity
- Abiotic diversity
Correct Answer: Biodiversity
Q3. Which layer of a forest is most associated with interception of sunlight and primary productivity?
- Forest floor
- Understory
- Canopy
- Emergent layer
Correct Answer: Canopy
Q4. Net primary productivity (NPP) equals:
- Gross primary productivity plus respiration
- Gross primary productivity minus respiration
- Respiration minus gross primary productivity
- Decomposition rate minus respiration
Correct Answer: Gross primary productivity minus respiration
Q5. Which process returns organic matter from dead plants to the soil as inorganic nutrients?
- Photosynthesis
- Herbivory
- Decomposition
- Transpiration
Correct Answer: Decomposition
Q6. Mycorrhizal associations in forests primarily aid plants by:
- Fixing atmospheric nitrogen
- Enhancing water and nutrient uptake
- Increasing herbivore resistance
- Producing secondary metabolites
Correct Answer: Enhancing water and nutrient uptake
Q7. Which forest type is typically richest in species and a major source of medicinal plants?
- Boreal forest
- Tropical rainforest
- Temperate coniferous forest
- Mangrove forest
Correct Answer: Tropical rainforest
Q8. Which is an abiotic factor influencing forest ecosystem function?
- Soil pH
- Herbivore density
- Mycorrhizal diversity
- Plant species richness
Correct Answer: Soil pH
Q9. Edge effects in fragmented forests often lead to:
- Greater interior habitat stability
- Increased core area for species
- Changes in microclimate and species composition
- Reduced sunlight at edges
Correct Answer: Changes in microclimate and species composition
Q10. Which index measures species diversity considering both richness and evenness?
- Biomass index
- Shannon index
- Productivity ratio
- Canopy cover index
Correct Answer: Shannon index
Q11. Litterfall contributes most directly to which forest ecosystem function?
- Primary productivity
- Nutrient cycling
- Pollination
- Seed dispersal
Correct Answer: Nutrient cycling
Q12. Which organism group is the primary driver of decomposition in forest soils?
- Primary producers
- Detritivores and saprotrophic fungi
- Herbivores
- Pollinators
Correct Answer: Detritivores and saprotrophic fungi
Q13. Secondary metabolites produced by forest plants are important to B.Pharm students because they:
- Are the main energy source for herbivores
- Act as pharmaceutical lead compounds
- Increase net primary productivity
- Reduce soil erosion
Correct Answer: Act as pharmaceutical lead compounds
Q14. Which nutrient cycle is most closely linked to microbial activity in forest soils?
- Carbon cycle
- Phosphorus cycle
- Nitrogen cycle
- All of the above
Correct Answer: All of the above
Q15. A keystone species in a forest is one that:
- Is the most abundant species
- Has a disproportionately large effect on ecosystem structure
- Is always a top predator
- Only occurs in disturbed habitats
Correct Answer: Has a disproportionately large effect on ecosystem structure
Q16. Which method is commonly used to estimate plant species abundance in a forest?
- Randomized controlled trials
- Quadrat sampling
- Western blotting
- Gas chromatography
Correct Answer: Quadrat sampling
Q17. Forest succession refers to:
- Short-term daily changes in photosynthesis
- Progressive change in species composition over time
- Seasonal leaf fall only
- Immediate responses to herbivory
Correct Answer: Progressive change in species composition over time
Q18. Which component is considered a biotic factor in forest ecosystems?
- Soil texture
- Ambient temperature
- Fungal decomposers
- Sunlight intensity
Correct Answer: Fungal decomposers
Q19. Primary production in forests is largely limited by:
- Availability of herbivores
- Light, water, and nutrient availability
- Decomposer abundance
- Seed dispersal mechanisms
Correct Answer: Light, water, and nutrient availability
Q20. Which technique helps map forest cover and monitor changes at landscape scale?
- High-performance liquid chromatography
- Remote sensing and GIS
- Quadrat technique only
- Soil core microscopy
Correct Answer: Remote sensing and GIS
Q21. Which trophic level directly consumes primary producers?
- Primary consumers (herbivores)
- Secondary consumers
- Decomposers
- Detritivores
Correct Answer: Primary consumers (herbivores)
Q22. Bioindicator species in forests are used to:
- Increase timber yield
- Indicate environmental quality or change
- Enhance soil fertility artificially
- Replace medicinal plants
Correct Answer: Indicate environmental quality or change
Q23. Which process moves water from soil through plants to the atmosphere?
- Evapotranspiration
- Infiltration
- Runoff
- Leaching
Correct Answer: Evapotranspiration
Q24. Which chemical form of nitrogen is most readily taken up by forest plants?
- Nitrogen gas (N2)
- Ammonium (NH4+) and nitrate (NO3-)
- Urea only
- Elemental nitrogen
Correct Answer: Ammonium (NH4+) and nitrate (NO3-)
Q25. Which factor most strongly influences decomposition rates in forests?
- Leaf color
- Temperature and moisture
- Canopy height only
- Herbivore diversity
Correct Answer: Temperature and moisture
Q26. Which term describes nonliving physical and chemical parts of the environment?
- Biotic factors
- Abiotic factors
- Trophic factors
- Symbiotic factors
Correct Answer: Abiotic factors
Q27. Which organism is critical for nitrogen fixation in some forest ecosystems?
- Mycorrhizal fungi
- Rhizobia and some cyanobacteria
- Earthworms
- Leaf-litter beetles
Correct Answer: Rhizobia and some cyanobacteria
Q28. Forests provide ecosystem services that include:
- Provisioning of medicinal plants and timber
- Regulation of climate and water cycling
- Habitat for biodiversity and cultural services
- All of the above
Correct Answer: All of the above
Q29. Which concept refers to the maximum number of individuals an ecosystem can support?
- Carrying capacity
- Resilience
- Trophic cascade
- Ecological niche
Correct Answer: Carrying capacity
Q30. Allelopathy in forest plants involves:
- Mutualistic nutrient exchange
- Chemical inhibition of other plants
- Physical shading only
- Pollinator attraction
Correct Answer: Chemical inhibition of other plants
Q31. Which measurement distinguishes between standing biomass and productivity?
- Leaf area index versus NPP
- Soil pH versus humus content
- Canopy height only
- Herbivore count
Correct Answer: Leaf area index versus NPP
Q32. Which practice helps sustainable harvesting of medicinal plants in forests?
- Clear-cutting large tracts
- Selective harvesting and cultivation
- Complete removal of understorey
- Frequent burning of forest floor
Correct Answer: Selective harvesting and cultivation
Q33. Which process describes movement of nutrients from vegetation to soil and back to vegetation?
- Migration
- Biogeochemical cycling
- Succession
- Pollination
Correct Answer: Biogeochemical cycling
Q34. Which forest layer contains seedlings and shade-tolerant herbs?
- Canopy
- Understory
- Emergent layer
- Upper canopy only
Correct Answer: Understory
Q35. Which is a likely consequence of decreased forest biodiversity for drug discovery?
- Increased availability of novel compounds
- Reduced pool of potential medicinal compounds
- No impact on pharmacognosy
- Immediate increase in ecosystem productivity
Correct Answer: Reduced pool of potential medicinal compounds
Q36. Which organism group forms symbiotic associations that enhance phosphorus uptake?
- Arbuscular mycorrhizal fungi
- Herbivorous insects
- Large mammals
- Bird species
Correct Answer: Arbuscular mycorrhizal fungi
Q37. Carbon sequestration in forests is primarily stored in:
- Atmospheric CO2 only
- Plant biomass and soil organic matter
- Surface water bodies
- Herbivore tissues only
Correct Answer: Plant biomass and soil organic matter
Q38. Which sampling design reduces bias when estimating tree density?
- Convenience sampling
- Systematic or random sampling with transects/quadrats
- Sampling only near trails
- Sampling only tallest trees
Correct Answer: Systematic or random sampling with transects/quadrats
Q39. Which term describes the functional role of a species within an ecosystem?
- Carrying capacity
- Ecological niche
- Trophic level only
- Abiotic factor
Correct Answer: Ecological niche
Q40. Which human activity most directly causes forest fragmentation?
- Reforestation
- Agricultural expansion and road building
- Controlled tourism with minimal impact
- Scientific sampling
Correct Answer: Agricultural expansion and road building
Q41. Which measure indicates the rate at which organic matter is converted back to CO2 and nutrients?
- Photosynthetic rate
- Decomposition rate
- Canopy cover percentage
- Species richness index
Correct Answer: Decomposition rate
Q42. Pollination services in forests affect:
- Reproductive success of many plant species
- Soil erosion directly
- Decomposition rates only
- Atmospheric nitrogen levels
Correct Answer: Reproductive success of many plant species
Q43. Which factor would most likely reduce primary productivity in a forest?
- Increased sunlight
- Severe drought
- Optimal nutrient availability
- Warm growing season
Correct Answer: Severe drought
Q44. Which term describes the total living biomass contained in a forest at a given time?
- Primary productivity
- Standing crop (standing biomass)
- Decomposition pool
- Net ecosystem exchange
Correct Answer: Standing crop (standing biomass)
Q45. Which forest management approach prioritizes conservation of medicinal plant diversity?
- Monoculture plantations
- Community-based sustainable management
- Clear-felling for agriculture
- Unregulated commercial extraction
Correct Answer: Community-based sustainable management
Q46. Which factor enhances resilience of forest ecosystems to disturbance?
- Low species diversity
- High functional redundancy and connectivity
- Complete loss of keystone species
- Intensive fragmentation
Correct Answer: High functional redundancy and connectivity
Q47. In a forest food web, what role do decomposers play?
- They produce organic matter from sunlight
- They break down dead material and recycle nutrients
- They are primary consumers only
- They reduce soil fertility
Correct Answer: They break down dead material and recycle nutrients
Q48. Which analytical tool helps identify chemical constituents of medicinal plants collected from forests?
- Quadrat sampling
- Chromatography and mass spectrometry
- GIS mapping only
- Canopy height measurement
Correct Answer: Chromatography and mass spectrometry
Q49. Which characteristic of tropical forest soils often limits agricultural conversion despite high aboveground biodiversity?
- High nutrient retention in soil
- Low organic matter and rapid nutrient leaching
- Permafrost
- Excessively alkaline pH universally
Correct Answer: Low organic matter and rapid nutrient leaching
Q50. Which conservation strategy balances forest use and protection for long-term medicinal resource supply?
- Strict protection with no local use
- Sustainable harvesting combined with cultivation and habitat protection
- Immediate commercial exploitation
- Conversion to monoculture crops
Correct Answer: Sustainable harvesting combined with cultivation and habitat protection
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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