WBBSE Class 9 Life Science Chapter 5 Ecology And Ecological Organization Multiple Choice Questions

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Chapter 5 Environment And Its Resources Ecology And Ecological Organization Multiple Choice Questions

Question 1. Branch of science dealing with the interrelation of a species and its environment is—

  1. Autecology
  2. Synecology
  3. Community biology
  4. Population biology

Answer: 1. Autecology

Question 2. Synecology deals with —

  1. A single individual
  2. A population
  3. A community
  4. Different ecosystems

Answer: 3. A community

Question 3. At which level of ecology would you explain the event of change in body color of an animal with the change in intensity of light?

  1. Individual level
  2. Population level
  3. Community level
  4. Ecosystem level

Answer: 1. Individual level

Read and Learn More WBBSE Class 9 Life Science MCQs

Question 4. Synthesis of chlorophyll in green plants is controlled by—

  1. Relative humidity
  2. Atmospheric pressure
  3. Temperature
  4. Light

Answer: 4. Light

Question 5. The similarity amongst chlorophyll production, transpiration rate and opening of stomata is that—

  1. All are involved in growth of plants
  2. All are light dependent events
  3. All increase weight of plant body
  4. All decrease weight of plant body

Answer: 2. All are light dependent events

Question 6. All the plants and animals together of a particular area are called—

  1. Ecotone
  2. Biome
  3. Biota
  4. Echod

Answer: 3. Biota

Question 7. Absorption of water by plants is related to—

  1. Water content of soil
  2. Chlorophyll concentration
  3. Plant height
  4. Starch content of cells

Answer: 1. Water content of soil

Question 8. Xerophytes have—

  1. Thick cuticle cover
  2. Less stomata
  3. Thick stem hair
  4. All of these

Answer: 4. Thick stem hair

Question 9. Zooplanktons come to the surface in day light and go to the bottom at night, this is—

  1. Circadian rhythm
  2. Diurnal rhythm
  3. Photoperiodism
  4. Phototactic movement

Answer: 1. Circadian rhythm

Question 10. Heliophytes are adapted to—

  1. Saline soil
  2. Saline water
  3. Bright sunlight
  4. Low sunlight

Answer: 3. Bright sunlight

Question 11. Population interaction is discussed under—

  1. Population level
  2. Community level
  3. Ecosystem level
  4. Individual level

Answer: 2. Community level

Question 12. Rate of metabolism increases in—

  1. Low temperature
  2. Higher temperature
  3. Low humidity
  4. High CO2

Answer: 2. Higher temperature

Question 13. A growing population shows—

  1. Low natality
  2. High mortality
  3. Low natality and emigration
  4. Low mortality and immigration

Answer: 4. Low mortality and immigration

Question 14. ‘S’ shaped growth curve is seen in—

  1. Newly built ant population
  2. Stable human population
  3. Honey bee population
  4. Wasp population

Answer: 2. Stable human population

WBBSE Class 9 Life Science Chapter 5 Ecology And Ecological Organization Multiple Choice Questions

Question 15. High natality and immigration—

  1.  Increase population size
  2. Decrease population size
  3. Do not change population size
  4. None of these

Answer: 1.  Increase population size

Question 16. If B= Birth rate, N= Total number of individuals in a population and nb= Number of live birth, the equation for birth rate will be—

  1. N= \(\frac{nb}{B}\)
  2. B= \(\frac{nb}{N}\)
  3. B= N * nb
  4. B= \(\frac{N}{nb}\)

Answer: 2. B= \(\frac{nb}{N}\)

Question 17. Size of population remains unchanged if—

  1. Emigration = Immigration
  2. Natality > Mortality
  3. Immigration * Emigration
  4. All of these

Answer: 1. Emigration = Immigration

Question 18. Population size decreases with—

  1. Emigration
  2. Immigration
  3. Low mortality
  4. High natality

Answer: 1. Emigration

Question 19. A positive interspecific interaction is—

  1. Mutualism
  2. Parasitism
  3. Predation
  4. Cannibalism

Answer: 1. Mutualism

Question 20. Population size does not depend upon—

  1. Migration
  2. Natality
  3. Emigration
  4. Species interaction

Answer: 4. Species interaction

Question 21. High rate of predation results in—

  1. Decline in primary consumer
  2. Increase in primary consumer
  3. Decrease in higher level of consumer
  4. Decline in producer

Answer: 1. Decline in primary consumer

Question 22. In which of the following interactions, involved members keep very close contact?

  1. Competition
  2. Parasitism
  3. Predation
  4. None of these

Answer: 2. Parasitism

Question 23. What is ‘+ +’ interaction?

  1. Autotrophism
  2. Parasitism
  3. Symbiosis
  4. Predation

Answer: 3. Symbiosis

Question 24. Which of the following is a topographic factor of ecosystem?

  1. Brightness of light
  2. Wind speed
  3. Slope of hills
  4. Waves of sea

Answer: 3. Slope of hills

Question 25. Animals that maintain constant body temperature in any environment are called—

  1. Poikilothermic animals
  2. Homeothermic animals
  3. Eurythermal animals
  4. Stenothermal animals

Answer: 2. Homeothermic animals

Question 26. Example of stenothermal animals is—

  1. Birds
  2. Toads
  3. Ants
  4. Fishes

Answer: 4. Fishes

Question 27. Which of the following is an example of obligate parasite?

  1. Round worm
  2. Mosquito
  3. Louse
  4. Ticks

Answer: 1. Round worm

Question 28. Which of the following is not an abiotic factor?

  1. Water
  2. Soil
  3. Plants
  4. Air

Answer: 3. Plants

Question 29. Global ‘sink’ for CO2 is

  1. Tropical rain forest
  2. Mangrove
  3. Ocean
  4. Coral reef

Answer: 3. Ocean

Question 30. Which ecosystem has the highest primary productivity?

  1. Pond
  2. Ocean
  3. Desert
  4. Forest

Answer: 2. Ocean

Question 31. The most recently discovered ecosystem is—

  1. Vent*
  2. Crater
  3. Floating iceberg
  4. Coral reef

Answer: 1. Vent*

Question 32. Niche of a species is—

  1. Place of living
  2. Specific function
  3. Habitat and specific function
  4. None of these

Answer: 3. Habitat and specific function

Question 33. Which one of the following is mismatched?

  1. Deciduous forest: Shorea robusta
  2. Evergreen forest: Pinus roxburghii
  3. Xeric forest: Musa paradisica
  4. Mangrove forest: Barringtonia acutangula

Answer: 3. Xeric forest: Musa paradisica

Question 34. Insectivorous plants are—

  1. Organotrophs
  2. Autotrophs
  3. Heterotrophs
  4. Partial heterotrophs

Answer: 4. Partial heterotrophs

Question 35. Which of the following levels is not studied in synecology?

  1. Individual level
  2. Population level
  3. Community level
  4. Ecological level

Answer: 1. Individual level

Question 36. In ecology, interaction and organization among different organisms is studied in steps.

  1. 2
  2. 3
  3. 4
  4. 5

Answer: 3. 4

Question 37. Which of the following is a long day plant?

  1. pea
  2. Cosmos
  3. Strawberry
  4. Dahlia

Answer: 1. pea

Question 38. Which of the following is a short day plant?

  1. Pea
  2. Dahlia
  3. Clover
  4. Radish

Answer: 2. Dahlia

Question 39. Chlorophyll synthesis in plants is regulated by—

  1. Humidity
  2. Wind
  3. Temperature
  4. Light

Answer: 4. Light

Question 40. Melanin formation in human skin is regulated by—

  1. Humidity
  2. Light
  3. Temperature
  4. Pressure

Answer: 2. Light

Question 41. Migration of salmon, eel fish is regulated by—

  1. Water
  2. Humidity
  3. Temperature.
  4. Light

Answer: 3. Temperature.

Question 42. Temperature affects the size of an organism. This is known as—

  1. Bergmann’s rule
  2. Gloger’s rule
  3. Allen’s rule
  4. Lindeman’s law

Answer: 1. Bergmann’s rule

Question 43. Higher humidity makes the body colour of animals darker. This is known as—

  1. Bergmann’s rule
  2. Gloger’s rule
  3. Allen’s rule
  4. Lindeman’s law

Answer: 2. Gloger’s rule

Question 44. Animals of polar region have smaller pina, tail and limbs. This is known as—

  1. Bergmann’s rule
  2. Gloger’s rule
  3. Allen’s rule
  4. Lindeman’s law

Answer: 3. Allen’s rule

Question 45. The physiological reaction of organisms depending upon the length of day or night, is called—

  1. Photosynthesis
  2. Photoperiodism
  3. Photorespiration
  4. None of these

Answer: 2. Photoperiodism

Question 46. The act of leaving one’s native place permanently with the intent to reside somewhere else, is called—

  1. Adaptation
  2. Immigration
  3. Emigration
  4. Extinction

Answer: 3. Emigration

Question 47. Example of l+ O’ interaction is—

  1. Autotrophism
  2. Mutualism
  3. Parasitism
  4. Commensalism

Answer: 4. Parasitism

Question 48. All the plant species of an ecosystem is collectively known as—

  1. Flora
  2. Fauna
  3. Biome
  4. Biomass

Answer: 1. Flora

Question 49. All the animal species of an ecosystem is collectively known as—

  1. Flora
  2. Fauna
  3. Biome
  4. Biomass

Answer: 2. Fauna

Question 50. Number of trophic levels in a food chain ranges from—

  1. 14-16
  2. 11-13
  3. 7-10
  4. 3-5

Answer: 4. 3-5

Question 51. Lindeman law of energy flow through different trophic levels in an ecosystem is also known as—

  1. 5% law
  2. 7% law
  3. 10% law
  4. 15% law

Answer: 3. 10% law

Question 52. Which of the following is a grazing food chain?

  1. Organic matter → Earthworm → Bacteria
  2. Plant → Human → Worm
  3. Decaying organic matter → Zooplankton → Small fish → Large fish
  4. Grass → Grasshopper → Frog → Snake → Hawk

Answer: 4. Grass → Grasshopper → Frog → Snake → Hawk

Question 53. Actively swimming aquatic organisms in a water body are called—

  1. Necton
  2. Benthos
  3. Plankton
  4. Neuston

Answer: 1. Necton

Question 54. Food chain was scientifically described in 1966 by scientist—

  1. Tansley
  2. Lindeman
  3. Odum
  4. Flaeckel

Answer: 3. Odum

Question 55. The community of organisms, that reside on or near the seabed is called—

  1. Necton
  2. Plankton
  3. Benthos
  4. Neuston

Answer: 3. Benthos

Question 56. The largest consumer population of marine ecosystem belongs to—

  1. Primary consumer
  2. Secondary consumer
  3. Tertiary consumer
  4. Topmost level of consumers

Answer: 1. Primary consumer

Question 57. Photoperiodism is a—

  1. Biochemical process
  2. Biophysical process
  3. Physiological process
  4. All of these

Answer: 3. Physiological process

Question 58. Man is—

  1. Autotroph
  2. Omnivorous
  3. Carnivorous
  4. Herbivorous

Answer: 2. Omnivorous

Question 59. If different trophic levels are piled one upon another, we shall get—

  1. Food chain
  2. Food web
  3. Food pyramid
  4. Energy pyramid

Answer: 3. Food pyramid

Question 60. Which of the following is a component of macronutrient cycle?

  1. Na
  2. Mn
  3. Cu
  4. O2

Answer: 4. O2

Question 61. Which of the following is a component of micronutrient cycle?

  1. Cu
  2. C
  3. H2
  4. O2

Answer: 1. Cu

Question 62. Inhabitance of Anabaena in the leaf tissue of Azolla is an example of— .

  1. Competition
  2. Predation
  3. Symbiosis
  4. Commensalism

Answer: 3. Symbiosis

Question 63. In an interspecific relation, one of the two species is benefited but another one is neither benefited nor harmed. This interaction is called—

  1. Symbiosis
  2. Mutualism
  3. Commensalism
  4. Parasitism

Answer: 3. Commensalism

Question 64. Certain bacteria break organic molecules and return elementary components to nature, these, bacteria are treated as—

  1. Decomposers
  2. Putrifying bacteria
  3. Transducers
  4. Transformers

Answer: 4. Transformers

Question 65. Unit of a population is—

  1. A community
  2. An animal species
  3. A plant species
  4. An individual of a species

Answer: 4. An individual of a species

Question 66. Unit of a community is—

  1. An individual of a species
  2. A plant species
  3. An animal species
  4. A Population

Answer: 4. A Population

Question 67. The largest population in an ecosystem is seen amongst—

  1. Decomposers
  2. Producers
  3. Primary consumers
  4. Secondary consumersintra

Answer: 2. Producers

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