MCQs

Answer Key for previous questions
51. (b) 52. (d) 53. (b) 54. (d)
55. (b) 56. (d) 57. (d) 58. (c) 59. (a) 60. (d)
61. (d) 62. (b) 63. (d) 64. (d) 65. (a) 66. (d)
67. (c) 68. (b) 69. (c) 70. (c) 71. (b) 72. (c)
73. (a) 74. (d) 75. (c) 76. (d) 77. (d) 78. (a)
79. (a) 80. (b) 81. (d) 82. (c) 83. (b) 84. (c)
85. (d) 86. (a) 87. (c) 88. (b) 89. (d) 90. (a)
91. (d) 92. (a) 93. (b) 94. (d) 95. (a) 96. (b)
97. (d) 98. (a) 99. (d) 100. (c)
1. Minimata disease is due to pollution by
(a) Organic waste into drinking water
(b) Oil spills in oceans
(c) Industrial waste mercury into fishing water
(d) Entry of Cadmium into drinking water
2. The maximum water pollution is caused by-
(a) Detergents (b) Pesticides
(c) Industrial wastes (d) Ammonia
3. Biogas consist of-
(a) CH4, SO2 and H2 (b) CO2, Alcohol and H2
(c) CH4, CO2
and water (d) All of the above
4. The Ozone layer saves from lethal UV. It mainly absorbs-
(a) UV-A (b) UV-B
(c) UV-A & B (d) UV-A & C
5. A non harmful species copies a harmful and tasteless form, the type of mimicry
shown is-
(a) Bateson (b) Mullerian
(c) Darwinian (d) Morganarian
6. Exotic weed which proved very harmful for forest and grassland is-
(a) Eupatromia (b) Verbenia
(c) Eichornia (d) Salvia
7. Latest news of conflicts between human and wild animals has happened due to-
(a) Habitat destruction
(b) Increased poaching
(c) Increased conservation
(d) Increased Human population
8. Biological magnification is maximum in human it proves that human is-
(a) Top consumer in food chain
(b) More susceptible
(c) Major Pollutant
(d) Most efficient in storage of reserve food
9. Benthic organism of lakes or sea are usually-
(a) Producer (b) Herbivores
(c) Carnivores (d) Decomposers364 CSIR-NET Life Sciences
10. Among the following which is not an characteristic of r-Selected species-
(a) Short maturation time
(b) Short life span
(c) Small size of offspring’s
(d) More then one time offspring production
11. In India most of plant flowers during spring or summer because-
(a) It is breeding season for butterflies
(b) More solar radiation are available
(c) Fruit and seed setting must be complete before onset of monsoon
(d) Environmental fluctuations are low
12. Total energy available for work at equilibrium is termed as-
(a) Free energy (b) Entropy
(c) Activation energy (d) Enthalpy
13. Drosophila shares more its genes with sister (75%) as compare to its daughter (50%)
due to-
(a) Eusocialbilty (b) Kin selection
(c) Haploidy diploidy (d) Parthenogensis
14. The gradual mode of speciation in single lineage in which species diverge in spurts of
relatively rapid change which result in increase in species is termed as-
(a) Punctuated equilibrium (b) Adaptive radiation
(c) Anagenesis (d) Cladogenesis
15. Profitability of prey for predator lies in its energy content and
(a) Prey density (b) Palatability
(c) Foraging time (d) prey availability
16. Net productivity of closed ecosystem is-
(a) 0 (b) <0
(c) >0 (d) +1/–1
17. Number of individual surviving to reproductive stage is termed as-
(a) Fecundity (b) Net reproduction rate
(c) Survivorship curve (d) Reproductive Mortality
18. Major source of green house gases are-
(a) Burning of plants (b) Burning of fossil fuels
(c) Respiration (d) Use of LPG
19. Global warming is due to-
(a) Absorption of UV by Ozone (b) Absorption of IR by CO2
(c) Absorption of IR by ozone (d) Absorption of UV by CO2Practice Test Paper – Environmental Biology 365
20. Soil in naturally growing vegetation is-
(a) Acidic due to Bicarbonate in soil
(b) Basic due to Bicarbonate in soil
(c) Neutral
(d) Acidic due to Sulphuric acid
21. Deepest enriched soil with nutrients is present at-
(a) Tropical rain forests (b) Dry deciduous forests
(c) Grasslands (d) Conifers
22. Maximum biodiversity occurs at-
(a) Tropics (b) Equator
(c) Temperate (d) Shooth
23. Rapid nutritional recycling takes place in-
(a) Coral (b) Deserts
(c) Grasslands (d) Oceans
24. When a marine fish is placed in fresh water, it dies becuase-
(a) Entry of water and it floats (b) Exit of water and shrinks
(c) Deficiency of salts (d) Deficiency of nutrients
25. In winter pollution rate enhances due to-
(a) SPM (b) SO2
and NO2
(c) Burning of fuels (d) Low temperature
26. Which is correct relationship between habitat disturbance and biodiversity-
(a) Areas with no habitat disturbance tends to have high biodiversity
(b) Areas with high habitat disturbance tends to have high biodiversity
(c) Areas with moderate habitat disturbance tends to have high biodiversity
(d) Areas with no habitat disturbance tends to have low biodiversity
27. The birds in tropics are generally smaller in size because of-
(a) To increase surface area to volume ratio
(b) To decrease surface area to volume ratio
(c) For easy flight
(d) Aestivation
28. In an pond ecosystem, net productivity by zooplankton is ‘p’ and biomass consumed
by small fishes is 'c', then the ratio of c/p is termed as-
(a) Assimilation efficiency (b) Net secondary productivity
(c) Consumption efficiency (d) Conversion efficiency
29. For climax which statement is INCORRECT?
(a) Number of perennial species increases
(b) Dependency on detritious food chain increases
(c) Vertical stratification of community increases
(d) Exploitation competition is more then normal competition366 CSIR-NET Life Sciences
30. At present, the relationship between human and monkey can be stated as
(a) They both have common ancestors
(b) Human have evolved from monkey
(c) Both have very distinct phylogeny
(d) Relationship can not be established
31. Each organism occupies a particular trophic level in a food chain. Moving from one
trophic level to the nex involves an energy loss of about ...
(a) 10% (b) 30%
(c) 50% (d) 70%
(e) 90%
32. The greatest amount of food per acre is produced in the ...
(a) tundra (b) grassland
(c) marine biome (d) rain forest
33. Predator populations and types of decomposers are biotic environmental factors. Which
is an abiotic environmental factor?
(a) common flora (b) availability of prey
(c) presence of microbes (d) average precipitation
34. Which of these is a large reservoir of nitrogen that is unusable by most organisms?
(a) soil (b) ocean
(c) atmosphere (d) space
35. The concentration of which gas can be reduced by preventing forest depletion?
(a) Oxygen (O2) (b) Methane (CH4)
(c) Carbon dioxide (CO2) (d) Nitrous oxide (N2O)
36. What is the approximate increase in global surface temperatures in the past century?
(a) 1.5°F (.8°C) (b) 5°F (2.8 °C)
(c) 1°F (.5°C) (d) 2°F (1.1°C)
37. What the gas which contributes most to the Greenhouse Effect?
(a) Methane(CH4) (b) Carbon dioxide (CO2)
(c) All of the above (d) Nitrous oxide (N2O)
38. What has been the approximate rise in sea level over the past century?
(a) 14-16 inches (35-40 cm) (b) 10-12 inches (25-30 cm)
(c) 2-4 inches (5-10 cm) (d) 6-8 inches (15-20 cm)
39. This type of biome (habitat) has very long cold winters, short warm summers and
typically has acidic soils as a result of the cold temperatures and litter fall.
(a) Desert (b) Tundra
(c) Taiga (Coniferous forests) (d) Temperate forests
40. A population’s role in the community or the resources it uses is called its _____?
(a) Trophic structure (b) Niche
(c) Community interaction (d) HabitatPractice Test Paper – Environmental Biology 367
41. Two species or populations are competing for the exact same resources, and one will
eventually exclude the other. What is the technical term for this?
(a) Predation (b) Competitive exclusion
(c) Coevolution (d) Mutualism
42. Predators can influence the structure of a community because their removal from
the community causes a catastrophic change in the composition and structure of the
rest of the community. What are the predators called because of this?
(a) Keystone species (b) Oppourtunists
(c) Coevolutionists (d) Edge species
43. What is the single most important factor contributing to losing or creating endangered
species?
(a) air pollution (b) clearcut logging
(c) habitat loss (d) water pollution
44. Which process is most capable of slowing global warming?
(a) Decomposition (b) Respiration
(c) Photosynthesis (d) Chemosynthesis
45. Why have top predators (consumers at the top of the food chain), such as the cheetah
and the tiger, always had smaller populations than organisms lower in the food chain?
(a) Hunted by humans (b) Low birth rate
(c) Limited energy availability (d) None of the above
46. Which of these is NOT a characteristic of a rapid life-history organism?
(a) rapid period of time until maturation
(b) small body size
(c) early reproduction age
(d) long life span
47. Based on the data in the graph, which of these statements is true?
(a) Growth of the housefly population begins to
increase rapidly about 3/4 of the way through
the first year
(b) At the beginning of the year, there are no
houseflies in the population
(c) The population size shows a straight-line
increase
(d) All of the population will be dead at the end
of one year
48. __________ is a density-dependent factor.
 (a) Competition (b) Temperature
(c) Drought (d) Floods
 368 CSIR-NET Life Sciences
49. Which of these is an explanation of why a population can fluctuate once it has reached
carrying capacity?
 (a) All populations experience exponential growth once they reach carrying capacity
 (b) A population of organisms always grows rapidly once it reaches carrying capacity
(c) Limiting factors can influence the number of organisms in a population once it
reaches carrying capacity
(d) The number of organisms decreases but never increases once it reaches carrying
capacity
50. Ecosytem is mainly concerned with
(a) energy flow and nutrient recycling (b) population
(c) community (d) species

Answers
1. (b) 2. (b) 3. (a) 4. (a) 5. (b) 6. (d)
7. (d) 8. (a) 9. (b) 10. (a) 11. (d) 12. (d)
13. (a) 14. (b) 15. (b) 16. (c) 17. (b) 18. (d)
19. (c) 20. (a) 21. (d) 22. (c) 23. (b) 24. (d)
25. (c) 26. (c) 27. (d) 28. (c) 29. (d) 30. (d)
31. (a) 32. (b) 33. (c) 34. (b) 35. (b) 36. (d)
37. (d) 38. (a) 39. (d) 40. (d) 41. (c) 42. (d)
43. (c) 44. (d) 45. (d) 46. (c) 47. (c) 48. (d)
49. (d) 50. (b)


Note: please consider that, these questions are gathered from web source and text books. The blog author is not responsible for errors and confusion.