Ecology & Environment MCQs Part 8

1) A soil which is formed by particles carried and suspended in water is called
a) Sedimentary
b) Eolian
c) Alluvial
d) Clay

2) Deforestation may reduce the chance of
a) Rainfall
b) Frequent cyclones
c) Erosion of surface soil
d) Frequent land slides

3) Which of the following is not a climax vegetation?
a) Forests
b) Grasses
c) Savannah
d) Hydrophytes

4) Identify the incorrect statement among the following statements on the effects of deforestation:
a) It destroys the natural habitat of wild animals
b) It alters the local weather patterns
c) It speeds up nutrient recycling
d) It leads to soil erosion

5) If enriched air is inhaled for a long time it causes
a) Diarrhoea
b) Bronchitis
c) Whooping cough
d) Allergy

6) Domestic waste contains
a) Non-biodegradable pollutants
b) Biodegradable pollutants
c) Hydrocarbon
d) None of these

7) Which of these pollutants is not produced by the exhaust of a motor vehicle?
a) SO2 and NO2

b) Flyash
c) CO and SO2

d) Hydrocarbon

8) Polluted water can be purified by using
a) Microorganisms
b) Algae
c) Pesticides
d) Fishes

9) The greenhouse effect is due to the presence of the
a) Ozone layer in the atmosphere
b) Infra-red light reaching the earth
c) Moisture layer in the atmosphere
d) CO2 layer in the atmosphere

10) Which of the following can be used in the purification of sewage?
a) Blue-green algae
b) Unicellular green algae
c) Fungi
d) All plants

11) The substance which produces resistance against carcinogens is
a) Aflatoxin
b) Tocoferol
c) Penicillic acid
d) Streptomycin

12) Sounds above what level are considered hazardous noise pollution?
a) Above 80 db
b) Above 120 db
c) Above 30 db
d) Above 100 db

13) Often in water bodies subjected to sewage pollution, fishes die because of the
a) Pathogens released by the sewage
b) Clogging of their gills by solid substances
c) Reduction in dissolved oxygen caused by microbial activity
d) Foul smell

14) The first bioherbicide developed in 1981 was based on
a) Phytophthora palmivora
b) Phytophthora infestans
c) Bacillus thuringenesis
d) Azadirachta indica

15) The experimental system used in studies of the discovery of replication of DNA was
a) Drosophila melanogaster
b) Pneumococcus
c) Escherichia coli
d) Neurospora crassa

16) The occurrence of zoochlorellae in the body wall of Hydra is an example of a food chain involving a parasite called
a) Predation
b) Commensalism
c) homeostasis
d) Mutualism or symbiosis

17) The water left in the soil after suction due to gravity is
a) Available water
b) Vital capacity
c) Hygroscopic water
d) Ground water

18) An American plant which had become a troublesome aquatic weed in India is
a) Cyperus rotundus
b) Eichhornia crassipes
c) Typha latifolia
d) Typha bispinosa

19) The maximum contribution of O2 is from

a) Phytoplankton
b) Grasslands
c) Herbs and shrubs
d) Dense forests

20) A renewable source of energy is
a) Coal
b) Kerosene
c) Petroleum
d) Biomass

21) Domestic wastes contain
a) Non-biodegradable pollutants
b) Biodegradable pollutants
c) Hydrocarbons
d) None of the above

22) River water carries
a) Sandy soil
b) Alluvial soil
c) Loamy soil
d) Laterite soil

23) Endemic plants are those which grow in
a) Geographically limited areas
b) Fresh water lakes
c) Shady places
d) Tissues of other plants

24) The nature of the climax community ultimately depends on the
a) Climate
b) Soil organisms
c) Bed rock
d) Pool of available nutrients

25) What is the source of energy to an ecosystem ?
a) Solar energy
b) Sugar stored
c) Heat liberated during respiration
d) ATP

26) In a grassland ecosystem the pyramid of energy is
a) Inverted
b) Upright
c) Inverted or upright
d) None of these

27) Biotic potential refers to the
a) Increase of population under optimum conditions
b) Increase of population under given conditions
c) Increase of population under natural conditions
d) Increase of population under climatic conditions

28) What is the ecological equivalent of horses in the Australian savannah?
a) Zebra
b) Bison
c) Antelope
d) Kangaroo

29) Which of the following shows the correct sequence in a food chain?
a) Fallen leaves – bacteria – insect larvae – birds
b) Phytoplankton – zooplankton – fish
c) Grasses – fox – rabbit
d) Grasses – chameleon – insects – birds

30) The food chain pyramid of an ecosystem is always upright in the
a) Parasitic food chain
b) Lake ecosystem
c) Grassland
d) ocean

31) Which ecological pyramid can never occur in an inverted form?
a) Pyramid of species richness
b) Pyramid of numbers
c) Pyramid of biomass
d) Pyramid of energy

32) In a food chain, the largest population is that of
a) Producers
b) Decomposers
c) Tertiary consumers
d) Primary consumers

33) The ecosystem having the highest rate of gross primary production is
a) an equatorial rain forest
b) a grassland
c) those which attain a large biomass
d) those which contribute to ecosystem properties

34) “Biocoenosis” is the study of the
a) Environment
b) Living
c) Interaction between the living and the non-living
d) None of these

35) Phosphorus usually becomes a limiting factor at certain times of the year in which type of ecosystem?
a) Aquatic ecosystem
b) Grasslands ecosystem
c) Forest ecosystem
d) None of these

36) Which of the following is most important in maintaining the nitrogen balance of nature?
a) Bacteria
b) Cyanobacteria
c) Green plants
d) Animals

37) The fertilizer that supplies the least percentage of nitrogen and phosphorus to the soil is
a) Ammonium sulphate
b) Ammonium nitrate
c) Urea
d) Super phosphate

38) The biomass produced by plants in oceans accounts for

55 %


65 %


75 %


85 %

39) Which one of the following pairs is a sedimentary type of biogeochemical cycle?
a) Phosphorous and carbon dioxide
b) Oxygen and nitrogen
c) Phosphorus and nitrogen
d) Phosphorus and sulphur

40) Insecticides kill
a) Only specific insects
b) Only plant pests
c) Harmful insects
d) Both harmful and useful insects

41) Which of the following is an organochlorine?
a) Aldrine
b) D.D.T.
c) Malathion
d) Parathion

42) Biological control of agricultural pests, unlike chemical controls is
a) Very expensive
b) Toxic
c) Self perpetuating
d) Polluting

43) The major drawback of D.D.T. as a pesticide is that
a) Organisms at once develop resistance to it
b) It is significantly less effective than other pesticides
c) Its cost of production is high
d) It is not easily and rapidly degraded in nature

44) Uprooting of weeds is a method of controlling them
a) Mechanically
b) Manually
c) Chemically
d) Biologically

45) Which pesticide has very low biodegradation and strong affinity for fatty tissues are
a) Triazines
b) Organochlorines
c) Pyrethoids
d) Organophosphates

46) The first bioinsecticide to be developed on a commercial scale was
a) Sporeine
b) Morphine
c) Quinine
d) None of these

47) Which of the following is most commonly used for green manuring in India?
a) Lentil
b) Cow pea
c) Sunn hemp
d) All of these

48) Basic slag is
a) Water soluble phosphatic fertiliser
b) Citric acid and soluble phosphatic fertiliser
c) Insoluble phosphatic fertiliser
d) None of these

49) A biofertilizer is
a) A cyanobacterium like Anabaena sp. living in the cavities of Azolla leaves
b) Symbiotic bacteria like Azotobacter which fix atmospheric nitrogen
c) Farmyard manure consisting of mixture of cattle dung and crop residues
d) Green manure in which a quick growing crop is cultivated and ploughed under

50) Straight fertilisers contain
a) One primary nutrient
b) Two primary nutrient
c) Three primary nutrients
d) Many primary nutrients

51) The main source of biofertilizers are
a) Biopesticide
b) bacteria
c) Fertilizer
d) Bionutrient

52) Genetic erosion is caused by
a) Adoption of genetically uniform varieties of crops
b) Shifting cultivation
c) Deforestation
d) All of these

53) Ridley wheat is an example of
a) Plant introduction
b) Hybridisation
c) Mass selection
d) Clonal selection

54) Which of the following is an under-utilized oil crop?
a) Brassica campestris
b) Cocos nucifera
c) Azadirachta indica
d) None of these

55) Liquid wax can be obtained from
a) Guayule
b) Jojoba
c) Winged bean
d) All of these

56) Which of these are not correctly matched?
a) Leucaena leucocephala – fixes atmospheric nitrogen
b) Psophocarpus tetragonolobus – seeds are nutritive
c) Simmondsia chinesis – liquid wax is obtained
d) Parthenium argentatum – furniture wood is obtained

57) The value of extra terrestrial light reaching the biosphere or the value of the solar constant is

1 g cal/cm2/min


2 g cal/cm2/min


10 g cal/cm2/min


30 g cal/cm2/min

58) Petroleum resource is
a) Renewable
b) Non renewable
c) Synthetic and biodegradable
d) Infinite and unconventional

59) Gobar gas mainly consists of

CO2 +  H2


CO2 +  SO2


CH4 + CO2


CH4 + O2

60) Biogeochemical cycling refers to cycling of
a) Energy in the ecosystem
b) Nutrients in the ecosystem
c) Water
d) Gases between plants and animals.

61) Nitrogen fixation is
a) Nitrogen ® Ammonia
b) Nitrogen ® Nitrates
c) Nitrogen ® Amino acid
d) Both A and B.

62) Which of the following depicts nitrogen fixation?
a) N2 + 3H2 ® 2NH3
b) 2NH3 ® N2 + 3H2
c) 2N2 + Glucose ® 2 amino acids
d) 2NH4+ + 2O2 g 8e® N2 + 4H2O.

63) Which one is a sedimentary cycle?
a) Oxygen cycle
b) Nitrogen cycle
c) Hydrogen cycle
d) Phosphorus cycle

64) A grassland with scattered trees is a
a) Savannah
b) Deciduous forest
c) Evergreen forest
d) Tropical rain forest

65) The difference between a tropical rain forest and a temperate forest is that
a) Tropical foresta have more angiosperms while temperate forests have more gymnosperms
b) A tropical forest is homogeneous while a temperate one is heterogeneous
c) Plants of temperate forests are more mesophytic
d) Trees of temperate forests are taller than those of tropical forests.

66) Relative to roots, the shoots are massive in plants of the
a) Desert
b) Moist temperate habitat
c) Tundra
d) Moist tropical forests

67) The driving force for an ecosystem is
a) Biomass
b) Producers
c) Carbohydrates in producers
d) Solar energy

68) How many tropic levels can a food chain have?
a) Three or four
b) Three
c) Two
d) One

69) In a food chain, herbivores/deer/grasshoppers are
a) Primary producers
b) Primary consumers
c) Secondary consumers
d) Decomposers.

70) The first link in a food chain is a green plant because
a) It alone can synthesise food
b) It is fixed at one place
c) It can pick up every thing
d) It can eat every thing.

71) A food chain in which microorganisms break down the food formed by primary producers is a
a) Parasitic food chain
b) Detritus food chain
c) Consumer food chain
d) Predator food chain

72) If phytoplankton are destroyed it will
a) Cause a spurt in the population of primary consumers
b) Rapid growth of algae
c) Affect the food chain
d) Have no effect

73) Nepenthes belongs to the category of
a) Primary consumer
b) Producer
c) Secondary consumer
d) Both B and C.

74) A young crocodile has eaten a lamb. A hawk attacks the crocodile and consumes the same. In ecological terms, the hawk is a
a) Producer
b) Primary consumer
c) Secondary consumer
d) Tertiary consumer

75) *Maximum human population can be supported if all the humans are
a) Carnivores
b) Pure vegetarian
c) Vegetarian along with use of milk
d) Vegetarian alongwith use of milk and eggs.

76) In a biotic community, the most important factor for survival of an animal is the
a) Day length
b) Soil moisture
c) Green food
d) Predators

77) A desert biome does not support much vegetation as it lacks
a) Sufficient light
b) Favourable temperature
c) Sufficient water
d) Sufficient nutrients

78) Tropical dry deciduous forests occur in India in
a) Andamans
b) Eastern Himalayas
c) Madhya Pradesh
d) Kerala

79) A biome with broad-leaved resinous fire resistant drought enduring plants is a
a) Savannah
b) Steppes
c) Chapparal
d) Deciduous forest

80) A biotic community along with its interacting physical environment comprises
a) Phytosociology
b) Phytogeography
c) Ecosystem
d) Ecology

81) Sal forest (Shorea robusta) is a/an
a) Deciduous forest
b) Evergreen forest
c) Rain forest
d) None of the above

82) Which part of the world has the highest density of organisms?
a) Grasslands
b) Savannahs
c) Deciduous forests
d) Tropical rain forests.

83) The maximum biomass of autotrophs in the oceans is made up of
a) Benthic brown algae, coastal red algae and daphnids
b) Benthic diatoms and marine viruses
c) Sea grasses and slime moulds
d) Free floating microalgae, cyanobacteria and nanoplankton

84) Which one has always a steeper vertical gradient?
a) Pyramid of mass
b) Pyramid of energy
c) Pyramid of numbers
d) Pyramid of energy in aquatic ecosystem

85) An association which fixes nitrogen through non-nodulation is
a) Maize roots with Spirillium notatum
b) Digitaria roots with Spirillium notatum
c) Coralloid roots of Cycas with Anabaena
d) All the above

86) The pyramid of energy is always upright indicating that
a) Producers have the lowest energy conversion efficiency
b) Carnivorous have a better energy efficiency than herbivores
c) Energy conversion efficiency is same for all trophic levels
d) Herbivores have a better energy conversion efficiency than carnivores.

87) Choose the wrong pair:
a) Salvadora – Desert
b) Cenchrus – Savanna
c) Tectona – Temperate forest
d) Abies – Coniferous forest

88) The eosystem with the highest primary productivity is the
a) Pond
b) Ocean
c) Desert
d) Forest

89) The extinction of a species in a food chain is compensated in a/an
a) Ecological pyramid
b) Food web
c) Food chain
d) None of the above

90) Phytoplankton are dominant in the
a) Limnetic zone
b) Profundal zone
c) Littoral zone
d) Benthic zone

91) Synecology is the study of inter-relationships between the environment and the
a) Individual plant
b) A population
c) A community
d) Individual animal

92) The sum total of the populations of the same kind of organisms constitute a
a) Colony
b) Genus
c) Community
d) Species

93) Submerged hydrophytes have a well developed
a) Vascular system
b) Aerenchyma
c) Root system
d) Stomatal system

94) Which character is not present in the hydrophytes?
a) Poor roots
b) Plentiful xylem and sclerenchyma
c) Leaves with stomata on upper surface or absent
d) Abundant aerenchyma.

95) The abyssal zone of the ocean has
a) No sunlight but contains consumers and decomposers
b) No sunlight but contains producers
c) No sunlight but contains living beings
d) Sunlight as well as producers.

96) Animals that can tolerate a narrow range of salinity are
a) Stenohaline
b) Euryhaline
c) Anadromous
d) Catadromous.

97) Which one is partially submerged and fixed in mud?
a) Marsilea
b) Cyperus
c) Eichhornia
d) Typha.

98) Vivipary occurs in
a) Betula
b) Rhizophora
c) Mango
d) Psidium

99) Humus is an example of
a) A fertilizer
b) Component of soil structure
c) Organic colloids
d) Crystalloids

100) The amount of water a soil can hold against the pull of gravity is called its
a) Field capacity
b) Gravitational water
c) Storage water
d) Hygroscopic water.



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