Productivity in an ecosystem
1. Which term refers to the rate at which energy or biomass is produced in an ecosystem?
a) Net primary productivity
b) Gross primary productivity
c) Secondary productivity
d) Tertiary productivity
Answer: b) Gross primary productivity
2. What is the main factor that limits primary productivity in aquatic ecosystems?
a) Temperature
b) Sunlight availability
c) Nutrient availability
d) Water depth
Answer: c) Nutrient availability
3. Which type of ecosystem generally has the highest primary productivity?
a) Tropical rainforests
b) Deserts
c) Tundra
d) Oceans
Answer: a) Tropical rainforests
4. What is the role of photosynthetic organisms in primary productivity?
a) They convert sunlight into chemical energy
b) They break down organic matter
c) They consume other organisms for energy
d) They regulate the population of other species
Answer: a) They convert sunlight into chemical energy
5. How is primary productivity measured in an ecosystem?
a) By counting the number of species present
b) By measuring the total biomass of organisms
c) By determining the rate of carbon dioxide uptake
d) By analyzing the nutrient content of the soil
Answer: c) By determining the rate of carbon dioxide uptake
6. What is the difference between gross primary productivity (GPP) and net primary productivity (NPP)?
a) GPP includes energy used by primary producers, while NPP represents the energy available to consumers
b) GPP measures productivity in terms of biomass, while NPP measures it in terms of energy
c) GPP represents the total energy fixed by primary producers, while NPP is the energy available for growth and reproduction
d) GPP accounts for losses through respiration, while NPP accounts for losses through decomposition
Answer: c) GPP represents the total energy fixed by primary producers, while NPP is the energy available for growth and reproduction
7. Which factor has the greatest influence on terrestrial primary productivity?
a) Temperature
b) Precipitation
c) Soil fertility
d) Solar radiation
Answer: b) Precipitation
8. What is the primary role of primary productivity in an ecosystem?
a) To support the growth and reproduction of organisms
b) To regulate the carbon cycle
c) To maintain species diversity
d) To provide energy for higher trophic levels
Answer: a) To support the growth and reproduction of organisms
9. Which ecosystem has the lowest primary productivity?
a) Freshwater lakes
b) Coral reefs
c) Arctic tundra
d) Temperate forests
Answer: c) Arctic tundra
10. How does human activity, such as deforestation, impact primary productivity?
a) It increases primary productivity due to nutrient enrichment
b) It decreases primary productivity by removing photosynthetic organisms
c) It has no significant effect on primary productivity
d) It can have both positive and negative effects depending on the context
Answer: b) It decreases primary productivity by removing photosynthetic organisms
11. Which trophic level in an ecosystem typically has the lowest productivity?
a) Producers
b) Primary consumers
c) Secondary consumers
d) Tertiary consumers
Answer: d) Tertiary consumers
12. How does nutrient availability affect primary productivity in aquatic ecosystems?
a) Higher nutrient availability leads to higher primary productivity
b) Lower
nutrient availability leads to higher primary productivity
c) Nutrient availability has no significant effect on primary productivity in aquatic ecosystems
d) Nutrient availability only affects primary productivity in terrestrial ecosystems
Answer: a) Higher nutrient availability leads to higher primary productivity
13. What is the term used to describe the efficiency of energy transfer between trophic levels in an ecosystem?
a) Trophic efficiency
b) Biomass efficiency
c) Energy conversion efficiency
d) Productivity efficiency
Answer: a) Trophic efficiency
14. In an ecosystem, primary productivity is highest during which season?
a) Spring
b) Summer
c) Autumn
d) Winter
Answer: b) Summer
15. Which type of ecosystem is characterized by high primary productivity but low net productivity?
a) Estuaries
b) Coral reefs
c) Deserts
d) Grasslands
Answer: a) Estuaries
16. How does the availability of sunlight affect primary productivity in aquatic ecosystems?
a) Higher sunlight availability leads to higher primary productivity
b) Lower sunlight availability leads to higher primary productivity
c) Sunlight availability has no significant effect on primary productivity in aquatic ecosystems
d) Sunlight availability only affects primary productivity in terrestrial ecosystems
Answer: a) Higher sunlight availability leads to higher primary productivity
17. What is the primary factor that determines the productivity of an ecosystem?
a) Temperature
b) Precipitation
c) Nutrient availability
d) Solar radiation
Answer: d) Solar radiation
18. Which trophic level is responsible for the highest energy loss in an ecosystem?
a) Producers
b) Primary consumers
c) Secondary consumers
d) Tertiary consumers
Answer: c) Secondary consumers
19. What is the term used to describe the rate at which biomass is produced by photosynthesis in an ecosystem?
a) Gross primary productivity
b) Net primary productivity
c) Secondary productivity
d) Tertiary productivity
Answer: a) Gross primary productivity
20. How does primary productivity vary with depth in aquatic ecosystems?
a) It increases with depth due to increased nutrient availability
b) It decreases with depth due to reduced sunlight penetration
c) It remains constant at all depths in aquatic ecosystems
d) It varies depending on the temperature of the water
Answer: b) It decreases with depth due to reduced sunlight penetration
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