Category: CSIR NET Life Science Previous Year Questions and Solution on Ecosystem Ecology

Category: CSIR NET Life Science Previous Year Questions and Solution on Ecosystem Ecology

CSIR NET Life Science Previous Year Questions and Solution on Ecosystem Ecology

60. What is the significance of upwelling zone for marine ecosystems? (1) It is responsible for uniformity of temperature in ocean to support the marine life. (2) It brings nutrients from deeper zones to relatively nutrient poor ocean surface thus increasing marine productivity. (3) It is responsible for uniform oxygenation of marine waters thus increasing marine productivity. (4) It helps in circulating decomposers from the bottom of ocean to surface for proper decomposition of dead material on the surface.

The Significance of Upwelling Zones for Marine Ecosystems

59. Which of the following options lists ecosystems in increasing order of plant productivity per day per unit leaf area? (1) Tropical forests, hot deserts, temperate forests (2) Hot deserts, temperate forests, tropical forests (3) Hot deserts, temperate grasslands, tropical forests (4) Tropical forests, temperate grasslands, hot deserts

Plant Productivity Per Day Per Unit Leaf Area: Which Ecosystem Ranks Highest?

58. Which of the following is the correct increasing order for the daily net primary productivity (NPP) per unit leaf area in different ecosystems ? (1) Deserts < Temperate forests < Tropical forests (2) Deserts < Tropical forests < Temperate forests (3) Temperate forests< Tropical forests< Deserts (4) Tropical forests < Temperate forests < Deserts

Daily Net Primary Productivity (NPP) Per Unit Leaf Area: How Do Ecosystems Compare?

57. Which of the following is a correct ranking of ecosystems based on the roots: shoot ratio of plants? (1) Tropical wet forest > Tropical dry forest > Temperate grassland > Tropical grassland (2) Temperate grass land > Tropical grassland > Tropical wet forest > Tropical dry forest (3) Tropical dry forest > Tropical wet forest > Tropical grassland > Temperate grassland (4) Temperate grass land > Tropical grassland Tropical dry forest > Tropical wet forest

Ranking Ecosystems by Root:Shoot Ratio: Which Ecosystem Allocates Most Biomass Belowground?

56. Given below is an ecological pyramid. The above pyramid represents: (1) Pyramid of number of a parasitic food chain and pyramid of biomass of a pond ecosystem (2) Pyramid of number of a pond ecosystem and pyramid of biomass of a forest ecosystem (3) Pyramid of energy of a grassland and pyramid of biomass of an open ocean ecosystem (4) Pyramid of biomass of a grassland and pyramid of number of a tropical forest ecosystem

Understanding Ecological Pyramids: Matching Pyramid Types to Ecosystems

55. Which one of the following statement is NOT correct? (1) Herbivores enhance the productivity of a productive ecosystem and reduce the productivity of an unproductive ecosystem. (2) Detritus based food chains are longer in more productive ecosystem (3) Consumption efficiency of herbivores is higher in grasslands than ocean (4) Production efficiency of carnivores is higher than herbivores.

Which Statement About Herbivores and Food Chains Is Incorrect? Key Ecological Facts

54. Following are some of the generalizations regarding energy flow in an ecosystem: A. Assimilation efficiency of carnivores is higher than herbivores. B. Consumption efficiency of aquatic herbivores is higher than terrestrial herbivores. C. Vertebrates have higher production efficiencies than invertebrates. D. Trophic level transfer efficiency is higher in terrestrial food chains than in marine. Based on the above, select the correct option. (1) Only A and C (2) Only A and B (3) A, B and C (4) A, C and D

Understanding Energy Flow in Ecosystems: Key Generalizations and Their Ecological Significance

53. Following are certain statements regarding energy efficiencies of ectotherms and endotherms: A. Ectotherms have high assimilation efficiency but low production efficiency. B. Ectotherms have low assimilation efficiency but high production efficiency. C. Endotherms have high assimilation efficiency but low production efficiency. D. Endotherms have low assimilation efficiency but high production efficiency. Which one of the following represents the combination of correct statements? (1) A and B (2) B and C (3) C and D (4) A and C

Understanding Energy Efficiencies: Ectotherms vs. Endotherms

52. Which of the following is true about the Digestion Efficiency (DE)-(assimilation/consumption) and Ecological Efficiency (EE) (production/consumption) of ectotherms and endotherms? (1) Endotherms have a high DE and ectotherms have a high EE. (2) Endotherms have a low DE and ectotherms have a high EE. (3) Endotherms have a high DE and ectothenns have a low EE. (4) Endotherms have a low DE and ectotherms have a low EE.

Digestion Efficiency vs. Ecological Efficiency: Comparing Ectotherms and Endotherms

51. Lindeman's efficiency between trophic levels is depicted by the formula: Efficiency = A/B Where, A and B, respectively are: (1) 'assimilation at trophic level n' and 'assimilation at trophic level n - 1' (2) 'intake at trophic level n' and 'assimilation at trophic level n-1' (3) 'assimilation at trophic level n' and 'net productivity at trophic level n - 1' (4) 'intake at trophic level n' and productivity at trophic level n - 1'

What Is Lindeman’s Efficiency? Understanding the Formula and Its Components

50. Which of the following set of observations is true with reference to a comparison of aquatic (A) and terrestrial (T) ecosystems? (1) Number of trophic levels is more in A than T. Productivity/Biomass ratio is higher in T than in A. Herbivore assimilation efficiency is higher in A than in T. (2) Number of trophic levels is more in T than in A. Productivity/Biomass ratio is greater in A than in T. Herbivore assimilation efficiency is higher in T than in A. (3) Number of trophic levels is more in T than in A. Productivity/Biomass ratio is higher in T than in A. Herbivore assimilation efficiency is higher in T than in A. (4) Number of trophic levels is more in A than in T. Productivity/Biomass ratio is greater in A than in T. Herbivore assimilation efficiency is higher in A than in T.

Comparing Aquatic and Terrestrial Ecosystems: Trophic Levels, Productivity, and Herbivore Efficiency

49. The diagram below depicts energy flow within a single trophic level, where l-amount ingested, NA= amount not assimilated, R=respiration, and Pn = biomass production at trophic level. Which one of the following options represents correct values for Pn, NA, R and l in kcal respectively, if Pn-1 = 1000 kcal, 1/ Pn-1 = 20%, A/1 = 35% and Pn/A= 20%? (1) 56 14 130 200 (2) 14 130 56 200 (3) 200 130 56 14 (4) 56 130 200 14

How to Calculate Energy Flow Values in Trophic Levels Using Percentages

48. Autotrophs in the aquatic ecosystem, unlike their counterparts in the terrestrial ecosystem are mostly microscopic and very low in indigestible (to the herbivores) matter. This explains the fact that compared to the terrestrial ecosystem, in the aquatic ecosystem (1) Productivity/Biomass ratios are higher and energy transfer rates to higher trophic levels are faster. (2) Productivity/Biomass ratios are lower and the energy transfer rates to higher trophic levels are slower. (3) Productivity Biomass ratios are lower and the energy transfer rate to higher trophic levels are faster. (4) Productivity/Biomass ratios are higher and the energy transfer rate to higher trophic levels are slower

Why Are Aquatic Ecosystems More Productive and Efficient Than Terrestrial Ones?

47. The approximate P:B (Net Primary Production: Biomass) ratios in four different ecosystems (A, B, C, D) are A - 0.29; B - 0.042, C - 16.48; D - 8.2. The four ecosystems are (1) A - Ocean; B - Lake; C - Grassland; D - Tropical forest (2) A - Grassland; B - Tropical forest; C - Ocean; D - Lake (3) A - Tropical forest; B - Ocean; C - Grassland; D – Lake (4) A -Grassland; B - Ocean; C - Lake; D - Tropical forest

How to Match Net Primary Production:Biomass (P:B) Ratios to Ecosystems

46. The utilization or consumption efficiency of herbivores is highest in (1) plankton communities of ocean waters. (2) mature temperate forests. (3) managed grasslands. (4) managed rangelands.

Where Is Herbivore Utilization Efficiency Highest? Comparing Ocean Plankton, Forests, and Grasslands

45. A much greater proportion of energy fixed by autotrophs is transferred to the herbivore level in the open ocean ecosystem than in a forest ecosystem because (1) aquatic autotrophs are small. (2) aquatic herbivores are more efficient feeders. (3) terrestrial autotrophs are less efficient feeders. (4) terrestrial autotrophs have more indigestible tissues

Why Does More Energy Flow to Herbivores in the Open Ocean Than in Forests?

44. Which of the following is the correct decreasing order for the rate of decomposition of litter constituents? (1) Hemicellulose, cellulose, lignin, phenol (2) Cellulose, hemicellulose, phenol, lignin (3) Hemicellulose, cellulose, phenol, lignin (4) Lignin, phenol, hemicellulose, cellulose

What Is the Correct Order for the Rate of Decomposition of Litter Constituents?

43. Which of the following is likely to contribute to the stability of an ecosystem? (1) High number of specialists (2) Fewer number of functional links (3) More omnivores (4) Linear rather than reticulate food webs

Which Factors Contribute to Ecosystem Stability? Understanding the Role of Omnivores and Food Web Structure

42. In which ecosystem is the autotroph-fixed energy likely to reach the primary carnivore level in the shortest time? (1) Grassland (2) Temperate deciduous forest (3) Ocean (4) Tropical rain forest

Which Ecosystem Delivers Autotroph-Fixed Energy to Primary Carnivores the Fastest?

41. In which ecosystem is the detrital pathway of energy flow most important? (1) Lakes (2) Grasslands (3) Tropical rain forests (4) Oceans

Which Ecosystem Relies Most on the Detrital Pathway for Energy Flow

39. Below is a table showing the number of species and actual food web links observed in three different ecosystems. By calculating connectance as a measure of relative complexity of food webs, infer which of the following statements is correct? (1) Connectance increases as species richness increases. (2) Connectance decreases as species richness increases. (3) Connectance is constant regardless of species richness. (4) Relationship between species richness and connectance is stochastic.

Does Connectance Increase or Decrease with Species Richness in Food Webs

38. The complexity of a food web in a community is quantified using certain parameters which are defined below. Which of the following is an INCORRECT representation?

Understanding Food Web Complexity: How to Quantify and Identify Incorrect Representations

37. In a field experiment, autotrophs are provided a 14C- labelled carbon compound for photosynthesis. Radioactivity (14C) levels were then monitored at regular intervals in all the trophic levels. In which ecosystem is the radioactivity likely to be detected fastest at the primary carnivore level? (1) open ocean (2) Desert (3) Deciduous forest (4) Grassland 37. In a field experiment, autotrophs are provided a 14C- labelled carbon compound for photosynthesis. Radioactivity (14C) levels were then monitored at regular intervals in all the trophic levels. In which ecosystem is the radioactivity likely to be detected fastest at the primary carnivore level? (1) open ocean (2) Desert (3) Deciduous forest (4) Grassland

Which Ecosystem Transfers Radioactive Carbon to Primary Carnivores the Fastest?

36. The ecosystem having maximum energy from one trophic level to another is (1) Tropical rain forest (2) Ocean (3) Desert (4) Temperate Deciduous forest

Which Ecosystem Has the Maximum Energy Flow Between Trophic Levels?

35. The ecosystem having longest energy transfer time is (1) Tropical rain forest (2) Ocean (3) Desert (4) Temperate Deciduous forest

Which Ecosystem Has the Longest Energy Transfer Time? – Comparing Rainforests, Oceans, Deserts, and Temperate Forests

34. The most commonly used method of estimating primary productivity of a pond involves measurement of the amount (1) CO2 utilized (2) autotroph biomass. (3) oxygen released. (4) organic carbon

How is Primary Productivity Measured in Ponds? The Most Common Method Explained

33. Aquatic primary production was measured using Light-and-Dark Bottle technique. If the initial oxygen concentration was l and the final oxygen concentration in the light bottle is L and that in the dark bottle D, the gross productivity (in terms of oxygen released) is given as (1) D-L (2) l-D (3) l-L (4) L-D

How to Calculate Gross Primary Productivity Using the Light-and-Dark Bottle Method: A Step-by-Step Guide

32. Primary production in aquatic ecosystem is measured using Light-and-Dark-Bottle technique. In this method, as an indirect measure of photosynthetic production, dissolved oxygen concentration of the pond water enclosed in a BOD bottle is measured initially (l) and after a fixed duration of incubation in a light bottle (L) and a dark bottle (D). Then, the gross and net primary productions are estimated is (1) (L-D) and (L-l), respectively. (2) (L-l) and (L--D), respectively. (3) (L-l) and (l-D), respectively. (4) (L-D) and (l-D), respectively.

How to Measure Primary Production in Aquatic Ecosystems: The Light-and-Dark-Bottle Method

31. A researcher collected information from four forest using sensors to assess their green cover. Observed average spectral values from each of the forest are given in the table below: The forest cover in the order of highest to lowest is (1) A>C>B>D (2) A>D>C>B (3) B>C>D>A (4) D>A>B>C

How to Rank Forest Green Cover Using Spectral Sensor Data

30. Which of the following is the most appropriate spectral bands for vegetation analysis using remote sensing platforms? (1) Red, Near Infrared (2) Infrared, Visible (3) Red, Microwave (4) Visible, Microwave

Best Spectral Bands for Vegetation Analysis in Remote Sensing

29. Possible explanations for the age related decline in primary productivity of trees are: A. As trees grow larger with age, they have more tissues that respire and loose energy and proportionately less leaf area to photosynthesis. B. Nutrient limitation by nitrogen due to reduced rate of woody litter decomposition as forest ages. C. As trees become larger, water transport to the top canopy leaves becomes limited because of increased hydraulic resistance. This results in reduced stomatal conductance and reduction in photosynthetic rate. Which of the above is/are correct? (1) A, B and C (2) only A (3) only A and C (4) only B and C

Why Does Tree Productivity Decline With Age? – Exploring the Causes

28. Among the following maximum net primary productivity is observed at (1) Boreal forests (2) Swamps and Marsh (3) Tundra and alpine (4) Temperate grasslands

Which Ecosystem Has the Highest Net Primary Productivity? – Comparing Boreal, Swamps, Tundra, and Grasslands

27. Biomass turnover time is the ratio between biomass and production of an ecosystem. Which of the following forests should have highest biomass turnover time? (1) Tropical dry forests (2) Tropical wet forests (3) Temperate deciduous forests (4) Boreal forests

Which Forest Type Has the Highest Biomass Turnover Time? – Understanding Ecosystem Dynamics

26. What percentage of photo active radiation are actually utilized for photosynthesis by plants (1) Lesser then 0.1 (2) 1-3 (3) 10-20 (4) >20

What Percentage of Photosynthetically Active Radiation Is Used for Photosynthesis?

25. Among the following highest assimilation efficiency is observed in? (1) Herbivores (2) Carnivores (3) Microbivores (4) Omnivores

Which Group Has the Highest Assimilation Efficiency? – Comparing Herbivores, Carnivores, Microbivores, and Omnivores

24. In spite of the prevalence of large scale herbivory, the earth continues to be largely green because (1) the number of herbivore species is low. (2) herbivores are very inefficient feeders. (3) herbivore numbers are kept low by their predators. (4) plant produces tough, non-digestible biomass often with secondary metabolites which deter herbivory

Why Is the Earth Still Green Despite Widespread Herbivory? – The Science of Plant Defenses

23. Organisms with high growth and production are (1) Ectotherm (2) Endotherm (3) Carnivore Insects (4) Detrivores

Which Organisms Have the Highest Growth and Production Rates? – Comparing Ectotherms and Endotherms

22. Primary carnivores consume 40 % production of herbivore and assimilate 70 % of energy. What percentage of energy these carnivores assimilates out of the energy available from herbivores (1) 30 (2) 28 (3) 10 (4) 40

How Much Energy Do Carnivores Actually Assimilate from Herbivores? – Calculating Energy Transfer Efficiency

21. In ecosystem the concept of entropy is used to explain (1) Photosynthesis efficiency (2) Energy flow (3) Population growth (4) Competition

How Entropy Explains Energy Flow in Ecosystems

20. The special roots termed as pneumatophores are visible at (1) Mangroves (2) Oceans (3) Epiphytes (4) Salt stress

Where Are Pneumatophores Found? – Exploring the Unique Root Adaptations of Mangroves

19. Which one of the following statements about corals is NOT CORRECT? (1) Corals possess special stinging cells called nematocytes in their tentacles for capturing prey. (2) Several corals have mutualistic interactions with microorganisms called zooxanthellae that photosynthesize and pass some of the food to their hosts. (3) Reefs form when corals grow in shallow water close to the shores. (4) All corals grow only in the photic zones as they need sunlight for their growth.

Which Statement About Corals Is NOT Correct? – Debunking Common Myths and Facts

18. Consider the following ecosystems. A. Tropical rain forests B. Open ocean C. Algal beds and Coral reefs D. Marshes and Swamps Which one of the following options represents these ecosystems in an increasing order of their contribution to annual world net primary production? (1) B, C, D and A (2) C, D, B and A (3) D, C, A and B (4) C, D, A and B

Ranking Ecosystems by Their Contribution to Global Net Primary Production

17. Which one of the following curves correctly depicts the relationship of the NPP/GPP ratio with latitude? (1) A (2) B (3) C (4) D

Which Curve Best Represents the NPP/GPP Ratio Across Latitudes? – Understanding Global Patterns in Ecosystem Carbon Use Efficiency

16. Which one of the following options correctly lists ecosystems of the world arranged according to the descending order of their average world net primary production (billion kcal/yr)? (1) Tropical rain forests>Northern coniferous forests Open Oceans> Estuaries (2) Open Oceans> Tropical rain forests> Northern coniferous forests>Estuaries (3) Tropical rain forests Open Oceans>Northern coniferous forests> Estuaries (4) Open Oceans> Northern rain forests Estuaries> Northern coniferous forests

Which Ecosystems Have the Highest Total Net Primary Production? – Ranking the World’s Major Ecosystems

15. Which one of the following statements pertaining to global ocean ecosystem productivity is NOT correct? (1) Higher chlorophyll concentrations and the general higher productivity observed around the equator is driven by the process of upwelling and/or mixing of high nutrient subsurface water into the euphotic zone. (2) In some temperate and subpolar regions, productivity is least during the spring due to the transitioning of phytoplankton from light-limiting to nutrient-limiting conditions. (3) In the nutrient-poor tropical and subtropical ocean, the cyanobacteria tend to be numerically dominant, as they specialize in taking up nutrients at low concentrations. (4) Larger phytoplankton, such as diatoms, often dominate the nutrient-rich polar ocean, and these can be grazed directly by multicellular zooplankton.

Which Statement About Global Ocean Ecosystem Productivity Is NOT Correct? – Analyzing Key Facts

14. Study the global ecosystem data provided in the following table. Based on the data provided in the table, choose the correct option that represents ecosystems with the highest global primary production and the highest relative NPP, respectively. (1) Tropical rainforest and tropical rainforest (2) Swamp and marsh, and tropical rainforest (3) Cultivated land and open ocean (4) Open ocean and open ocean.

Which Ecosystems Have the Highest Global Primary Production and Highest NPP per Unit Area? – Analyzing Ecosystem Data

13. Correct order for increasing order of primary production is (1) Ocean-Desert-Tropical deciduous forest-Tropical rain forest (2) Desert-Tropical deciduous-Ocean-Tropical rain forest (3) Tropical rain forest-Ocean-Tropical deciduous- Deserts (4) Tropical deciduous-Desert-Ocean-Tropical rain forest

What Is the Correct Order of Increasing Primary Production? – Comparing Deserts, Oceans, Tropical Deciduous, and Tropical Rainforests

12. Among the following which has highest Productivity/Biomass ratio (1) Desert (2) Ocean (3) Rain forests (4) Grassland

Which Ecosystem Has the Highest Productivity/Biomass Ratio? – Comparing Deserts, Oceans, Rainforests, and Grasslands

11. Phytoplankton spends very' little energy on developing protective structures against predator, this suggest that why (1) Assimilation efficiency is high in aquatic ecosystem (2) Productivity of aquatic ecosystem is low (3) There is less competition in aquatic system (4) Length of food chain is small aquatic system

Why Do Phytoplankton Invest Little in Protective Structures Against Predators? – Implications for Aquatic Ecosystems

Among the following maximum primary productivity (P/B) is seen in? (1) Corals (2) Mangroves (3) Oceans (4) Lakes

Which Ecosystem Shows the Maximum Primary Productivity (P/B)? – Comparing Corals, Mangroves, Oceans, and Lakes

9. In comparison to aquatic ecosystem, in terrestrial ecosystem autotrophs invest their most of energy in production of material which are indigestible by heterotrophs because (1) Autotroph diversity is high in terrestrial ecosystems (2) Autotroph diversity is high in aquatic ecosystems (3) Herbivore diversity and density is high in terrestrial ecosystems (4) Energy takes a lesser period to pass from autotroph to top consumer in terrestrial ecosystem

Why Do Terrestrial Autotrophs Invest More Energy in Indigestible Material Than Aquatic Autotrophs? – Comparing Terrestrial and Aquatic Ecosystems

8.Among the following which is global cycle- (1) Carbon (2) Sulphur (3) Boron (4) Nitrogen

Which Elements Have a Global Cycle? – Understanding the Carbon, Sulphur, Boron, and Nitrogen Cycles

Learn what the ratio of biomass consumed by small fish (c) to net productivity by zooplankton (p) represents in a pond ecosystem. Explore the concepts of consumption, assimilation, conversion, and net secondary productivity.

Understanding Trophic Efficiencies in Pond Ecosystems: What Does the Ratio c/p Represent?

Which statement supports the second law of thermodynamics- (1) Photosynthetic efficiency of plants is low (2) There is limited numbers of tropic level (3) Energy transfer from one tropic level to another around 10 % (4) High numbers of producers

Which Statement Supports the Second Law of Thermodynamics in Ecology? – Understanding Energy Flow and Trophic Levels

Rapid nutritional recycling takes place in- (1) Coral (2) Deserts (3) Grasslands (4) Oceans

Where Does Rapid Nutrient Recycling Occur? – Exploring Coral Reefs, Deserts, Grasslands, and Oceans

Net productivity of closed ecosystem is- (1) 0 (2) 0 (4) +1/-1

What Is the Net Productivity of a Closed Ecosystem? – Understanding Ecosystem Productivity and the Concept of Closed Systems

Pyramid of biomass may be inverted in- (1) Desert (2) Oceans (3) Tundra (4) Grasslands

Where Can the Pyramid of Biomass Be Inverted? – Exploring Marine and Terrestrial Ecosystems

2. Average percentage (%) energy transferred from plants to herbivores is- (1) 1 (2) 10 (3) 50 (4) 80

What Is the Average Percentage of Energy Transferred from Plants to Herbivores? – Understanding the 10% Rule in Ecosystems

1. The ecological pyramid which is always upright is (1) Energy (2) Number (3) Biomass (4) None of these

Which Ecological Pyramid Is Always Upright? – Understanding Energy, Number, and Biomass Pyramids

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