1. Decomposers like fungi and bacteria are:
i. autotrophs
ii. heterotrophs
iii. saprotrophs
iv. chemo-autotrophs.
Choose the correct answer:
a) I and iii,
b) I and iv
c) ii and iii,
d) I and ii
Answer: c;
2. The process of mineralization by microorganisms helps in the release of:
a) inorganic nutrients from the humus
b) both organic and inorganic nutrients from detritus
c) organic nutrients from the humus
d) inorganic nutrients from detritus and the formation of humus.
Answer: a;
3. Productivity is the rate of production of biomass expressed in terms of:
i. (kcal m–3) yr–1
ii. g–2 yr–1
iii. g–1 yr–1
iv. (kcal m–2) yr–1
a) ii,
b) iii,
c) ii and iv,
d) i and iii
Answer: c;
4. An inverted pyramid of biomass can be found in which ecosystem?
a) Forest
b) Marine
c) Grassland
d) Tundra
Answer: b;
5. Which of the following is not a producer?
a) Spirogyra
b) Agaricus
c) Volvox
d) Nostoc
Answer: b; Agaricus is a fungus.
6. Which of the following ecosystems is most productive in terms of net primary production?
a) Deserts
b) Tropical rainforests
c) Oceans
d) Estuaries
Answer: b;
7. Pyramid of numbers is:
a) Always upright
b) Always inverted
c) Either upright or inverted
d) Neither upright nor inverted
Answer: c;
8. Approximately how much of the solar energy falls on the leaves of a plant is converted to chemical energy by photosynthesis?
a) Less than 1%
b) 2-10%
c) 30%
d) 50%
Answer: b;
9. Among the following, where do you think the process of decomposition would be the fastest?
a) Tropical rainforest
b) the Antarctic
c) Dry arid region
d) Alpine region
Answer: a; because of high humidity and temperature.
10) How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?
a) 1%
b) 10%
c) 40%
d) 90%
Answer: b;
11. During the process of ecological succession the changes that take place in communities are:
a) Orderly and sequential
b) Random
c) Very quick
d) Not influenced by the physical environment.
Answer: a;
12. Climax community is in a state of:
a) non-equilibrium
b) equilibrium
c) disorder
d) constant change.
Answer: b;
13. Among the following biogeochemical cycles which one does not have losses due to respiration?
a) Phosphorus
b) Nitrogen
c) Sulphur
d) All of the above
Answer: d;
14. The sequence of communities of primary succession in water is:
a) phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses, and trees.
b) phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses, and trees.
c) free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses, and trees.
d) phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow, and trees.
Answer: d;
15. The reservoir for the gaseous type of bio-geochemical cycle exists in
a) stratosphere
b) atmosphere
c) ionosphere
d) lithosphere
Answer: b;
16. If the carbon atoms fixed by producers already have passed through three species, the trophic level of the last species would be.
a) scavenger
b) tertiary producer
c) tertiary consumer
d) secondary consumer
Answer: a;
17. Which of the following type of ecosystem is expected in an area where evaporation exceeds precipitation, and mean annual rainfall is below 100mm
a) Grassland
b) Shrubby forest
c) Desert
d) Mangrove
Answer: c;
18. The zone at the edge of a lake or ocean which is alternatively exposed to air and immersed in water is called:
a) Pelagic zone
b) Benthic zone
c) Lentic zone
d) Littoral zone
Answer: d;
19. Edaphic factor refers to:
a) Water
b) Soil
c) Relative humidity
d) Altitude
Answer:b;
20. Which of the following is an ecosystem service provided by a natural ecosystem?
a) Cycling of nutrients.
b) Prevention of soil erosion.
c) Pollutant absorption and reduction of the threat of global warming.
d) All of the above.
Answer: d;
21. Which one of the following has the largest population in a food chain?
a) Producers
b) Primary consumers
c) Secondary consumers
d) Decomposers
Answer: d;
22. The second trophic level in a lake is
a) Phytoplankton
b) Zooplankton
c) Benthos
d) Fishes
Answer: b;
23. Secondary producers are
a) Herbivores
b) Producers
c) Carnivores
d) None of the above
Answer: a;
24. What is the percentage of photosynthetically active radiation (PAR) in the incident solar radiation?
a) 100%
b) 50 %
c) 1-5%
d) 2-10%
Answer: b;
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