24 Questions with Answers and Explanations on “Ecosystem” for Biology Students:
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Q. 1. Mention any two examples of manmade ecosystem.
Ans. (1) Crop fields
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(2) Aquarium
Q. 2. Mention the basic requirement for any ecosystem to function and sustain.
Ans. Solar energy.
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Q. 3. Name the types of productivity and the organism responsible?
Ans. Primary productivity— plants.
Secondary productivity —consumers.
Q. 4. Mention the raw material of decomposition.
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Ans. Detritus.
Q. 5. Select the odd one out:
(a) Fecal matter,
(b) Dead leaves,
(c) Thermocol,
(d) Bark.
Ans. (c) Thermocol
Q. 6. Give an example to detritivore.
Ans. Earthworm.
Q. 7. Expand the term PAR.
Ans. Photosynthetically Active Radiation.
Q. 8. How much percentage of PAR is captured by the producers to produce food for entire world?
Ans. 2%—10%
Q. 9. Name the herbivores of terrestrial and aquatic ecosystem.
Ans. Terrestrial herbivore—Insects, birds, mammals.
Aquatic herbivore—Mollusc.
Q.10. Define trophic level.
Ans. The position occupied by the organisms in a food chain, due to their food or nutrition is called trophic level.
Q.11. What is the source of energy to decomposers?
Ans. Detritus or dead biomass.
Q.12. Expand the terms—GFC, DFC.
Ans. GFC—Grazing Food Chain
DFC—Detritus Food Chain.
Q. 13. Name the ecological pyramid that can never be inverted. Give a suitable explanation for it.
Ans. Pyramid of energy, because when energy flows from one particular trophic level to next trophic level there is always loss of some energy.
Q.14. Give any two examples of areas where primary succession occurs.
Ans. Bare rock, newly created pond.
Q.15. What do you understand by standing state of soil?
The amount of nutrients present in soil at any given time is called standing state.
Q. 16. Give two examples to each type.
(a) Gaseous type of nutrient cycle.
(b) Sedimentary cycle.
Ans.
(a) Nitrogen and carbon cycle.
(b) Sulphur and phosphorus cycle.
Q. 17. Fill in the blanks:
(a) Plants are called as_________ because they fix carbon dioxide.
(b) In an ecosystem dominated by trees, the pyramid (of numbers) is_________ type.
(c) In aquatic ecosystems, the limiting factor for the productivity is_________ .
(d) Common detritivores in our ecosystem are_________ .
(e) The major reservoir of carbon on earth is__________ .
Ans.
(a) Producers
(b) Upright
(c) Light
(d) Fungi and bacteria
(e) Ocean
Q. 18. Which one of the following has the largest population in a food chain?
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers
Ans.
(d) Decomposers.
Q. 19. The second trophic level in a lake is—
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes
Ans. (a) Zooplankton.
Q. 20. Secondary producers are—
(a) Herbivores
(b) Producers
(c) Carnivores
(d) None of the above.
Ans. (a) Herbivores
Q. 21. What is the percentage of photosynthetically active radiation (PAR), in the incident solar radiation:
(a) 100%
(b) 50%
(c) 1-5%
(d) 2-10%
Ans.
(b) 50%
Q.22. What happens to humus in soil?
Ans. It is further converted into inorganic nutrients by microbes.
Q. 23. Define standing crop.
Ans. The mass of living material (biomass) at a particular time as a trophic level is called standing crop.
Q. 24. What is climax community?
Ans. The changes that lead finally to a community that is in near equilibrium with the environment where it exists is called climax community.