NEET UG - Ecosystem - structure and function, energy flow, food chains food webs ecological pyramids Online Test (MCQ Quiz)

1. What is the primary role of producers in an ecosystem?

A) To decompose dead organic matter B) To convert light energy into chemical energy C) To consume other organisms for energy D) To regulate population sizes

2. Which of the following best defines a food chain?

A) A complex network of interconnected food chains B) The linear sequence of organisms where nutrients and energy are transferred C) The total mass of organisms in a given area or volume D) The interaction between biotic and abiotic components of an environment

3. In a typical grassland ecosystem, which organism is most likely to be a primary consumer?

A) Lion B) Grasshopper C) Grass D) Hawk

4. What does the term 'trophic level' refer to in an ecosystem?

A) The physical environment where an organism lives B) The position an organism occupies in a food chain C) The rate of nutrient cycling in an ecosystem D) The total biodiversity of an ecosystem

5. Which ecological pyramid is always inverted in aquatic ecosystems?

A) Pyramid of energy B) Pyramid of biomass C) Pyramid of numbers D) All pyramids are upright in aquatic ecosystems

6. The '10% law' of energy transfer in an ecosystem states that:

A) Only 10% of available energy is transferred to the next trophic level B) 10% of biomass is transferred to the next trophic level C) 10% of sunlight is captured by producers D) 10% of decomposers are present in an ecosystem

7. What is the primary function of decomposers in an ecosystem?

A) Producing oxygen through photosynthesis B) Breaking down dead organic matter and recycling nutrients C) Consuming primary consumers D) Transferring energy to producers

8. A food web is a more realistic representation of energy flow than a food chain because:

A) It shows only producers and consumers B) It illustrates that most organisms consume only one type of food C) It depicts the interconnectedness of multiple food chains D) It quantifies the exact energy transfer at each level

9. Which of the following is an example of a detritivore?

A) Cow B) Eagle C) Earthworm D) Algae

10. The pyramid of numbers in a forest ecosystem is usually upright because:

A) There are fewer producers than primary consumers B) There are many producers (trees) supporting fewer herbivores C) Energy transfer efficiency is very low D) Decomposers are the most abundant organisms

11. What is the main source of energy for almost all ecosystems on Earth?

A) Geothermal energy B) Chemical energy from hydrothermal vents C) Solar energy D) Energy stored in fossil fuels

12. Which trophic level consists of organisms that directly consume producers?

A) Producers B) Primary consumers C) Secondary consumers D) Tertiary consumers

13. What is biomass in the context of an ecosystem?

A) The total number of individuals of a species B) The rate of photosynthesis C) The total mass of living or organic matter in a given area or volume D) The amount of energy available at a specific trophic level

14. An ecosystem's structure is defined by its:

A) Energy flow pathways B) Biodiversity and species composition C) Nutrient cycling rates D) Abiotic factors only

15. Which type of ecological pyramid represents the total amount of living matter at each trophic level?

A) Pyramid of energy B) Pyramid of biomass C) Pyramid of numbers D) Pyramid of productivity

16. What is the term for organisms that produce their own food, usually through photosynthesis?

A) Consumers B) Decomposers C) Autotrophs D) Heterotrophs

17. In a food chain, tertiary consumers feed on:

A) Producers B) Primary consumers C) Secondary consumers D) Decomposers

18. Which of the following is a biotic component of an ecosystem?

A) Sunlight B) Temperature C) Soil D) Plants

19. The flow of energy in an ecosystem is:

A) Multidirectional B) Recyclable C) Unidirectional D) Cyclical

20. A pond ecosystem typically has which type of pyramid of biomass?

A) Upright B) Inverted C) Spindle-shaped D) Always irregular

21. What are ecological pyramids used to represent?

A) The physical structure of an ecosystem B) The population dynamics of a single species C) The quantitative relationships between trophic levels D) The rate of water cycle in an ecosystem

22. Which organisms are essential for nutrient cycling in an ecosystem?

A) Producers B) Primary consumers C) Secondary consumers D) Decomposers and detritivores

23. Which of the following is an abiotic component of an ecosystem?

A) Fungi B) Bacteria C) Water D) Insects

24. What limits the number of trophic levels in most ecosystems?

A) The availability of decomposers B) The decreasing energy transfer efficiency at each level C) The abundance of producers D) The complexity of the food web

25. If producers have 10,000 kcal of energy, how much energy is typically available to secondary consumers?

A) 1,000 kcal B) 100 kcal C) 10 kcal D) 1 kcal

26. Which of the following is an example of a producer in a terrestrial ecosystem?

A) Wolf B) Rabbit C) Oak tree D) Mushroom

27. What is the primary function of consumers in an ecosystem?

A) To produce organic compounds from inorganic substances B) To break down dead organic matter C) To obtain energy by feeding on other organisms D) To regulate atmospheric gases

28. The pyramid of energy is always upright because:

A) Energy is lost as heat at each trophic level B) Producers capture almost all available energy C) Consumers are more numerous than producers D) Decomposers are highly efficient

29. Which term describes all the living organisms in an ecosystem?

A) Habitat B) Niche C) Community D) Population

30. What is a 'standing crop' in ecological terms?

A) The rate of primary production B) The total biomass of organisms at a particular trophic level at a given time C) The number of species in an ecosystem D) The flow of energy through an ecosystem

31. In which type of ecosystem is the pyramid of numbers often inverted?

A) Desert B) Forest C) Grassland D) Aquatic (e.g., a large lake)

32. What happens to energy as it moves up trophic levels in an ecosystem?

A) It increases B) It remains constant C) It decreases D) It fluctuates randomly

33. Which of the following is an example of a secondary consumer in a grassland?

A) Grass B) Grasshopper C) Frog D) Eagle

34. The total of all chemical processes that occur in living organisms is known as:

A) Photosynthesis B) Respiration C) Metabolism D) Decomposition

35. What is the term for the role an organism plays in its ecosystem, including its interactions and resource use?

A) Habitat B) Niche C) Community D) Biome

36. In a simplified food chain: Grass -> Deer -> Wolf, what trophic level does the wolf occupy?

A) Producer B) Primary consumer C) Secondary consumer D) Tertiary consumer

37. Which statement best describes the function of ecological pyramids?

A) They show the predator-prey relationships B) They illustrate the cycling of nutrients C) They represent the relative amounts of energy, biomass, or numbers at each trophic level D) They predict the future population growth of species

38. What is the primary difference between a food chain and a food web?

A) Food chains are linear, food webs are complex networks B) Food chains involve only producers, food webs involve all trophic levels C) Food chains represent energy flow, food webs represent nutrient cycling D) Food chains are always upright, food webs are always inverted

39. Which component of an ecosystem is responsible for converting solar energy into chemical energy stored in organic compounds?

A) Primary consumers B) Secondary consumers C) Decomposers D) Producers (plants and algae)

40. The sum total of all the organisms of one species in a particular area is called a:

A) Community B) Ecosystem C) Population D) Biome

41. Which of the following is a characteristic of a decomposer organism?

A) Consumes living plants B) Feeds on dead organic matter C) Captures sunlight for energy D) Is at the top of most food chains

42. In a typical aquatic food chain, phytoplankton are:

A) Primary consumers B) Secondary consumers C) Producers D) Decomposers

43. The pyramid of biomass in a forest ecosystem is usually upright because:

A) The total biomass of producers (trees) is much greater than that of consumers B) There are fewer producers than consumers C) Energy transfer is 100% efficient D) Decomposers have the largest biomass

44. What does the base of an ecological pyramid represent?

A) The highest trophic level B) The producers C) The decomposers D) The apex predator

45. Which of the following is an example of a higher-level consumer that might be found at the top of a food web?

A) Grass B) Rabbit C) Fox D) Bacteria

46. The process by which organisms break down complex organic compounds into simpler inorganic substances is called:

A) Assimilation B) Respiration C) Decomposition D) Photosynthesis

47. What is the primary structure of an ecosystem related to its function?

A) The physical environment B) The species composition and trophic organization C) The rate of nutrient cycling D) The amount of sunlight available

48. In a food web, an organism that feeds on both plants and animals is called a(n):

A) Herbivore B) Carnivore C) Omnivore D) Detritivore

49. Which of the following represents the energy transfer from producers to primary consumers?

A) Tertiary consumption B) Secondary consumption C) Primary consumption D) Decomposition

50. What is the significance of the pyramid of energy?

A) It shows the population size of each trophic level B) It demonstrates the loss of energy at each trophic level C) It illustrates the recycling of nutrients D) It compares the biomass of different ecosystems

Ecosystem - structure and function, energy flow, food chains food webs ecological pyramids - Online Test

Test Results