NCERT - Ecosystem Questions and Answers for Class 12 | GkSeries

Questions
61 Which one of the following statements is correct for secondary succession?
1 It is similar to primary succession except that it has a relatively fast pace
2 It begins on a bare rock
3 It occurs on a deforested site
4 It follows primary succession

Answer: It occurs on a deforested site
62 An ecosystem which can be easily damaged but can recover after some time if damaging effect stops will be having
1 High stability and high resilience
2 Low stability and low resilience
3 High stability and low resilience
4 Low stability and high resilience

Answer: Low stability and high resilience
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63 Trophic levels in ecosystem is formed by :
1 only herbivores
2 only plants
3 only bacteria
4 Organisms linked in food chain

Answer:Organisms linked in food chain
64 "Complete competitors cannot coexist" is true for
1 Primary succession
2 Secondary succession
3 Competitive exclusion
4 Character displacement

Answer: Competitive exclusion
65 Terrestrial biomes has a rapid exchange of
1 Carbon dioxide
2 Oxygen
3 Water
4 All of the above

Answer: All of the above
66 The rate of formation of new organic matter by rabbit in a grassland, is called
1 Net productivity
2 Net primary productivity
3 Secondary productivity
4 Gross primary productivity

Answer: Secondary productivity
67 Ecology deals with the study of:
1 Living beings
2 Living and non living components
3 Reciprocal relationship between living and non living components
4 Environment

Answer: Reciprocal relationship between living and non living components
68 Acacia arabica is
1 Hydrophyte
2 Mesophyte
3 Xerophyte
4 None of these

Answer: Xerophyte
69 Of the total incident solar radiation the proportion of PAR is
1 More than 80%
2 About 70%
3 About 60%
4 Less than 50%

Answer: Less than 50%
70 Total amount of living material at the various trophic levels of a food chain is depicted by pyramids of
1 Numbers
2 Energy
3 Biomass
4 All of these

Answer: Biomass
71 The correct sequence of plants in a hydrosere is
1 Oak → Lantana → Volvox → Hydrilla → Pistia → Scirpus
2 Oak → Lantana → Scirpus → Pistia → Hydrilla → Volvox
3 Volvox → Hydrilla → Pistia → Scirpus → Lantana → Oak
4 Pistia → Volvox → Scirpus → Hydrilla → Oak → Lantana

Answer: Volvox → Hydrilla → Pistia → Scirpus → Lantana → Oak
72 The remains of the dead plants and animals is called
1 Detritus
2 Detritivores
3 Humus
4 Litter

Answer: Detritus
73 Bell-shaped polygonal pyramid indicates
1 Low percentage of young individuals
2 Moderate percentage of young individuals
3 High percentage of young individuals
4 Low percentage of old individuals

Answer: Moderate percentage of young individuals
74 Autoecology deals with
1 Ecology of species
2 Ecology of many species
3 Ecology of community
4 All the above

Answer: Ecology of species
75 The age of pyramid with broad base indicates
1 High percentage of old individuals
2 Low percentage of young individuals
3 High percentage of young individuals
4 Low percentage of old individuals

Answer: High percentage of young individuals

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