Grassland ecosystem – structure and function MCQs With Answer

Grassland ecosystem – structure and function MCQs With Answer provides B. Pharm students a focused review linking ecology to pharmacology. This introduction covers key concepts such as producers, consumers, decomposers, soil composition, nutrient cycles, primary productivity, fire and grazing dynamics, and how these influence medicinal plant distribution and phytochemical production. Emphasis on structure and function helps pharmacy students appreciate ecosystem services relevant to drug discovery, quality of herbal raw materials, and sustainable harvesting. Keyword-rich content ensures quick revision for exams and practical applications in pharmacognosy, pharmacology, and environmental toxicology. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the primary structural component of a grassland ecosystem?

• Woodland canopies
• Herbaceous vegetation dominated by grasses
• Permanent water bodies
• Epiphytic orchids

Correct Answer: Herbaceous vegetation dominated by grasses

Q2. Which group primarily drives primary productivity in grasslands?

• Soil fungi
• Herbivorous mammals
• Photosynthetic grasses and forbs
• Detritivores

Correct Answer: Photosynthetic grasses and forbs

Q3. Which factor most strongly influences grassland biome types (temperate vs. tropical)?

• Average wind speed
• Annual precipitation and temperature
• Latitude of the nearest ocean
• Soil pH alone

Correct Answer: Annual precipitation and temperature

Q4. What role do decomposers play in grassland function?

• They convert inorganic nutrients into organic matter
• They fix atmospheric nitrogen into plant proteins
• They break down organic matter, releasing nutrients back to soil
• They photosynthesize to produce carbohydrates

Correct Answer: They break down organic matter, releasing nutrients back to soil

Q5. How does grazing by large herbivores affect grassland structure?

• Always destroys all vegetation and prevents recovery
• Can maintain species diversity by preventing woody encroachment
• Eliminates decomposers
• Creates permanent wetlands

Correct Answer: Can maintain species diversity by preventing woody encroachment

Q6. Which soil horizon is most important for root growth in grasslands?

• O horizon (organic litter layer)
• A horizon (topsoil)
• B horizon (subsoil)
• C horizon (parent material)

Correct Answer: A horizon (topsoil)

Q7. Net primary productivity (NPP) equals:

• Gross primary productivity minus respiration by plants
• Respiration by consumers only
• Gross primary productivity plus detrital losses
• Only the energy lost as heat

Correct Answer: Gross primary productivity minus respiration by plants

Q8. Which ecosystem service from grasslands is directly relevant to supply of medicinal plants?

• Carbon sequestration only
• Provisioning of plant biodiversity and habitat for medicinal species
• Noise reduction
• Formation of coral reefs

Correct Answer: Provisioning of plant biodiversity and habitat for medicinal species

Q9. Mycorrhizal associations in grassland plants primarily enhance:

• Plant photosynthesis without nutrient exchange
• Water and nutrient uptake, especially phosphorus
• Predator avoidance
• Seed dispersal by animals

Correct Answer: Water and nutrient uptake, especially phosphorus

Q10. How can soil nutrient stress influence phytochemical production in medicinal plants?

• Stress always stops all secondary metabolite synthesis
• Moderate stress can increase secondary metabolites like alkaloids and phenolics
• Stress only reduces primary metabolites, not secondary
• Soil nutrients do not affect plant chemistry

Correct Answer: Moderate stress can increase secondary metabolites like alkaloids and phenolics

Q11. Which process returns nitrogen from organic matter to inorganic forms usable by plants?

• Photosynthesis
• Nitrification and ammonification by microbes
• Transpiration
• Denitrification to increase available nitrogen

Correct Answer: Nitrification and ammonification by microbes

Q12. Fire regimes in grasslands commonly promote:

• Conversion into closed-canopy forest immediately
• Maintenance of grass dominance and recycling of nutrients
• Permanent loss of soil microbes
• Increased salinity

Correct Answer: Maintenance of grass dominance and recycling of nutrients

Q13. Which component is considered an abiotic factor in grassland ecosystems?

• Herbivore populations
• Soil texture and mineral content
• Plant root exudates
• Mycorrhizal fungi

Correct Answer: Soil texture and mineral content

Q14. Edge effects in fragmented grasslands typically result in:

• Uniform species composition across fragments
• Increased microclimatic variability and invasion by non-grass species
• Decreased sunlight at edges only
• Total loss of pollinators

Correct Answer: Increased microclimatic variability and invasion by non-grass species

Q15. Which trophic level directly consumes primary producers in grasslands?

• Primary consumers (herbivores)
• Secondary consumers (predators)
• Decomposers only
• Apex predators

Correct Answer: Primary consumers (herbivores)

Q16. Functional diversity in grasslands refers to:

• Number of species only, ignoring traits
• Range of biological traits that influence ecosystem processes
• Only genetic diversity within a single species
• Human recreational uses

Correct Answer: Range of biological traits that influence ecosystem processes

Q17. Which practice can maintain medicinal plant quality in harvested grasslands?

• Unregulated overharvesting
• Sustainable harvesting protocols and habitat conservation
• Complete conversion to cropland
• Frequent high-intensity fires during seed set

Correct Answer: Sustainable harvesting protocols and habitat conservation

Q18. Allelopathy in grasslands is important because it:

• Enhances soil salinity
• Involves chemical inhibition of neighboring plants affecting composition
• Is irrelevant to plant interactions
• Only occurs in aquatic systems

Correct Answer: Involves chemical inhibition of neighboring plants affecting composition

Q19. Which measurement helps estimate aboveground biomass in grasslands?

• Soil electrical conductivity
• Clip-and-weigh method for plant biomass
• Water table depth
• Number of burrowing mammals

Correct Answer: Clip-and-weigh method for plant biomass

Q20. Which factor can alter the concentration of active compounds in medicinal grassland plants?

• Genotype, soil nutrients, light, and herbivory
• Only atmospheric pressure
• Presence of predators only
• Magnetic field of the Earth

Correct Answer: Genotype, soil nutrients, light, and herbivory

Q21. What is ecological succession in grasslands?

• Random distribution of seeds
• Gradual change in species composition over time following disturbance
• Immediate return to previous condition after disturbance
• Process of animal migration only

Correct Answer: Gradual change in species composition over time following disturbance

Q22. Which microbial group is vital for phosphorus solubilization in grassland soils?

• Nitrifying bacteria only
• Phosphate-solubilizing bacteria and fungi
• Viruses
• Macrofauna like earthworms only

Correct Answer: Phosphate-solubilizing bacteria and fungi

Q23. In grassland nutrient cycles, what is the primary sink for carbon?

• Atmospheric oxygen
• Soil organic matter and plant biomass
• Surface water bodies only
• Geological rock formation in weeks

Correct Answer: Soil organic matter and plant biomass

Q24. How does root architecture in grasses influence ecosystem function?

• Deeper fibrous roots enhance soil stabilization and carbon storage
• Rootless plants improve nutrient cycling
• Long taproots always decrease biodiversity
• Only aboveground parts matter for stability

Correct Answer: Deeper fibrous roots enhance soil stabilization and carbon storage

Q25. Which disturbance promotes mosaic habitats and increases species heterogeneity in grasslands?

• Complete urbanization
• Patchy grazing and low-intensity fires
• Permanent flooding of entire area
• Uniform application of heavy herbicides

Correct Answer: Patchy grazing and low-intensity fires

Q26. What is a keystone species in a grassland context?

• A species with a minor ecological role
• A species with disproportionately large effect on community structure
• Any species with highest abundance
• Only top predators in marine systems

Correct Answer: A species with disproportionately large effect on community structure

Q27. Which analytical technique is commonly used to quantify phytochemical variation in grassland medicinal plants?

• Thin-layer chromatography (TLC) and HPLC
• X-ray crystallography of soil minerals only
• Ultrasonography of roots
• Seismography

Correct Answer: Thin-layer chromatography (TLC) and HPLC

Q28. Which statement best links grassland biodiversity to drug discovery?

• Greater biodiversity increases likelihood of novel phytochemicals for pharmacology
• Biodiversity hinders drug isolation
• Only synthetic chemistry matters; biodiversity is irrelevant
• Pharmaceuticals are unaffected by plant diversity

Correct Answer: Greater biodiversity increases likelihood of novel phytochemicals for pharmacology

Q29. What is the role of pollinators in grassland ecosystem function relevant to pharmacy?

• Pollinators have no role in plant reproduction
• They enable reproduction of medicinal flowering plants affecting seed set and genetic diversity
• They increase soil erosion
• They produce secondary metabolites directly

Correct Answer: They enable reproduction of medicinal flowering plants affecting seed set and genetic diversity

Q30. Which management strategy reduces invasive plant spread in grasslands?

• Ignoring monitoring and removing natives
• Early detection, targeted removal, and restoration of native species
• Continuous heavy grazing everywhere
• Mass application of fertilizers only

Correct Answer: Early detection, targeted removal, and restoration of native species

Q31. Which factor most directly affects water availability for grassland plants?

• Seed color
• Soil texture and rainfall patterns
• Presence of herbivores only
• Length of predator guts

Correct Answer: Soil texture and rainfall patterns

Q32. How do earthworms and soil fauna contribute to grassland function?

• They compact soil and reduce fertility
• They enhance nutrient cycling, aeration, and organic matter decomposition
• They exclusively eat medicinal plant roots causing extinction
• They have no role in grasslands

Correct Answer: They enhance nutrient cycling, aeration, and organic matter decomposition

Q33. Which measurement indicates ecosystem resilience in grasslands?

• Ability to resist or recover from disturbances while maintaining function
• Absolute absence of any change after disturbance
• Total species extinction rate
• Only the height of the tallest grass

Correct Answer: Ability to resist or recover from disturbances while maintaining function

Q34. Which plant adaptation is common in arid grasslands?

• Shallow, extensive root systems and drought-tolerant physiology
• Large broad leaves with high transpiration
• Dependence on permanent standing water
• Brightly colored fruit for water storage

Correct Answer: Shallow, extensive root systems and drought-tolerant physiology

Q35. Which is an example of a provisioning service from grasslands important to pharmacy?

• Recreation areas only
• Raw plant material for herbal medicines and natural product leads
• Sensory noise reduction
• Improved urban skyline

Correct Answer: Raw plant material for herbal medicines and natural product leads

Q36. What effect does overgrazing have on soil and medicinal plant populations?

• Increases soil organic matter and medicinal plant abundance
• Leads to soil compaction, erosion, and loss of medicinal species
• Creates more wetlands beneficial for all herbs
• Only benefits pollinator populations

Correct Answer: Leads to soil compaction, erosion, and loss of medicinal species

Q37. Which concept explains energy transfer efficiency between trophic levels?

• Laws of electromagnetism
• 10% energy transfer rule (approximate trophic efficiency)
• Photosynthetic maximum efficiency of 100%
• Entropy reduction in ecosystems

Correct Answer: 10% energy transfer rule (approximate trophic efficiency)

Q38. Which practice can improve soil fertility in degraded grasslands?

• Monoculture planting of non-native grasses only
• Restoration with native species, controlled grazing, and organic amendments
• Complete removal of all vegetation for years
• Heavy metal contamination

Correct Answer: Restoration with native species, controlled grazing, and organic amendments

Q39. Which indicator species might signal healthy temperate grassland function?

• Reduction in pollinator numbers
• Presence of native perennial grasses and diverse forb assemblage
• Proliferation of single invasive grass species only
• Absence of decomposers

Correct Answer: Presence of native perennial grasses and diverse forb assemblage

Q40. Which human activity most directly reduces native grassland area?

• Conservation easements
• Agri‑intensification and urban expansion converting grasslands
• Low-impact ecotourism
• Traditional rotational grazing

Correct Answer: Agri‑intensification and urban expansion converting grasslands

Q41. What is the rhizosphere?

• The aboveground portion of a plant
• Soil region influenced by root exudates and microbial interactions
• Only the seed coat of plants
• An aquatic zone in wetlands

Correct Answer: Soil region influenced by root exudates and microbial interactions

Q42. How can climate change alter grassland pharmacognosy?

• By shifting species distributions and altering phytochemical profiles of medicinal plants
• By making all plants identical chemically
• Climate change has no ecological effects
• Only affects marine pharmacology

Correct Answer: By shifting species distributions and altering phytochemical profiles of medicinal plants

Q43. Which assessment is best for monitoring long-term changes in grassland biodiversity?

• Short one-day surveys only
• Long-term permanent plots and repeated sampling over years
• Counting only large mammals once
• Satellite photos without ground truthing forever

Correct Answer: Long-term permanent plots and repeated sampling over years

Q44. Which grassland process directly affects pharmaceutical supply chains?

• Availability and quality of medicinal plant raw materials influenced by land use change
• Number of mountain goats only
• Depth of oceanic trenches
• Daily sunrise time

Correct Answer: Availability and quality of medicinal plant raw materials influenced by land use change

Q45. Which restoration technique helps reestablish native medicinal herbs in degraded grasslands?

• Broadcast seeding of diverse native species and soil amelioration
• Planting fast-growing exotic trees only
• Continuous pesticide application
• Complete isolation from pollinators

Correct Answer: Broadcast seeding of diverse native species and soil amelioration

Q46. Which component of grassland structure is most directly linked to surface runoff control?

• Root networks and soil organic matter that increase infiltration
• Height of the tallest animal
• Number of pollinator species only
• Color of flowers

Correct Answer: Root networks and soil organic matter that increase infiltration

Q47. Which ecological interaction can influence secondary metabolite induction in plants?

• Herbivory and pathogen attack triggering defense compound synthesis
• Gravity changes alone
• Only lunar cycles with no biological cause
• Wind direction exclusively

Correct Answer: Herbivory and pathogen attack triggering defense compound synthesis

Q48. Which metric is useful for comparing productivity across grasslands?

• Gross primary productivity (GPP) or net primary productivity (NPP) per unit area
• Number of hikers per year
• Soil pH in isolation without context
• Height of a single plant only

Correct Answer: Gross primary productivity (GPP) or net primary productivity (NPP) per unit area

Q49. Which conservation approach balances medicinal plant harvest and ecosystem health?

• Community-based management with sustainable quotas and habitat protection
• Unregulated commercial extraction
• Complete ban on any use without alternatives
• Replacing native plants with ornamental species

Correct Answer: Community-based management with sustainable quotas and habitat protection

Q50. Why should B. Pharm students study grassland ecosystem structure and function?

• It is irrelevant to pharmacy practice
• To understand sources of medicinal plants, factors affecting phytochemistry, and sustainable sourcing
• Only for preparing landscaping designs
• To learn about ocean currents

Correct Answer: To understand sources of medicinal plants, factors affecting phytochemistry, and sustainable sourcing

G S Sachin

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.

Mail- Sachin@pharmacyfreak.com