Ecology MCQs
🌍 Ecology MCQs – Part 1 (Q1–Q25)
Q1. Ecology is best defined as the study of:
A) Organisms and their classification
B) Interactions between organisms and their environment
C) Evolution of species over time
D) Structure of cells
✅ Answer: B) Interactions between organisms and their environment
Explanation: Ecology studies how living organisms interact with each other and with abiotic factors.
Q2. Who is considered the “Father of Ecology”?
A) Charles Darwin
B) Ernst Haeckel
C) Gregor Mendel
D) Alfred Wallace
✅ Answer: B) Ernst Haeckel
Explanation: Haeckel coined the term ecology in 1866.
Q3. Which of the following is the correct hierarchy in ecology?
A) Species → Community → Population → Ecosystem
B) Organism → Population → Community → Ecosystem → Biome → Biosphere
C) Biosphere → Biome → Ecosystem → Population → Organism
D) Population → Ecosystem → Community → Biosphere
✅ Answer: B)
Explanation: Correct sequence is individual → population → community → ecosystem → biome → biosphere.
Q4. A population is defined as:
A) Different species in an area
B) Group of organisms of the same species in an area
C) All living organisms in a region
D) Group of communities in an area
✅ Answer: B)
Explanation: Population = members of same species in a defined area at a given time.
Q5. The sum of all ecosystems on Earth is called:
A) Community
B) Biome
C) Biosphere
D) Population
✅ Answer: C) Biosphere
Explanation: Biosphere includes all ecosystems on Earth (land, water, air).
Q6. Which biome has the highest biodiversity?
A) Desert
B) Temperate grassland
C) Tropical rainforest
D) Tundra
✅ Answer: C) Tropical rainforest
Explanation: Tropical rainforests have warm, wet climate → maximum species diversity.
Q7. The ecological niche of a species refers to:
A) Place where it lives only
B) Role and position a species has in its ecosystem
C) Community it belongs to
D) Physical structure of habitat
✅ Answer: B)
Explanation: Niche = functional role + habitat + interactions.
Q8. Which is an example of mutualism?
A) Mistletoe and tree
B) Bee and flower
C) Tick and dog
D) Tiger and deer
✅ Answer: B) Bee and flower
Explanation: Mutualism = both benefit. Bee gets nectar, flower gets pollinated.
Q9. Which is an example of commensalism?
A) Cattle egrets and grazing cattle
B) Tapeworm in human intestine
C) Lichen (algae + fungi)
D) Lion and hyena
✅ Answer: A) Cattle egrets and cattle
Explanation: Egret benefits by catching insects, cattle unaffected.
Q10. Which is an example of parasitism?
A) Orchid on mango tree
B) Algae and fungi in lichen
C) Bees and flowers
D) Fish shoaling
✅ Answer: A) Orchid on mango tree
Explanation: Orchid derives nutrition, tree harmed = parasitism.
Q11. Which pyramid is always upright in ecosystems?
A) Pyramid of energy
B) Pyramid of biomass
C) Pyramid of numbers
D) Pyramid of productivity
✅ Answer: A) Pyramid of energy
Explanation: Energy flow is unidirectional, always decreases at higher trophic levels.
Q12. The first trophic level in a food chain is occupied by:
A) Herbivores
B) Carnivores
C) Producers
D) Decomposers
✅ Answer: C) Producers
Explanation: Producers (plants, algae) convert solar energy into food.
Q13. Which organisms recycle nutrients back to the ecosystem?
A) Producers
B) Primary consumers
C) Decomposers
D) Herbivores
✅ Answer: C) Decomposers
Explanation: Bacteria and fungi break down dead material → release nutrients.
Q14. The rate at which producers synthesize energy is called:
A) Gross primary productivity (GPP)
B) Net primary productivity (NPP)
C) Secondary productivity
D) Ecological efficiency
✅ Answer: A) GPP
Explanation: GPP = total energy fixed; NPP = GPP – respiration.
Q15. The 10% law of energy transfer was proposed by:
A) Charles Darwin
B) Raymond Lindeman
C) Ernst Haeckel
D) Odum
✅ Answer: B) Raymond Lindeman
Explanation: Only ~10% of energy passes to next trophic level.
Q16. In a terrestrial ecosystem, the major reservoir of nitrogen is:
A) Plants
B) Atmosphere
C) Soil
D) Oceans
✅ Answer: B) Atmosphere
Explanation: Nitrogen gas (~78% of air) is the largest reservoir.
Q17. The process of converting ammonia into nitrites and nitrates is called:
A) Nitrogen fixation
B) Nitrification
C) Denitrification
D) Ammonification
✅ Answer: B) Nitrification
Explanation: Nitrifying bacteria convert NH₃ → NO₂⁻ → NO₃⁻.
Q18. Denitrification is carried out by:
A) Rhizobium
B) Azotobacter
C) Pseudomonas
D) Clostridium
✅ Answer: C) Pseudomonas
Explanation: Denitrifying bacteria convert NO₃⁻ → N₂, releasing nitrogen gas.
Q19. The greenhouse gas mainly responsible for global warming is:
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Argon
✅ Answer: B) Carbon dioxide
Explanation: CO₂ + CH₄ trap heat → enhanced greenhouse effect.
Q20. Which of the following is a non-renewable resource?
A) Solar energy
B) Coal
C) Wind
D) Forest biomass
✅ Answer: B) Coal
Explanation: Coal forms over millions of years → non-renewable.
Q21. The ozone layer protects life by absorbing:
A) Infrared radiation
B) Visible light
C) Ultraviolet radiation
D) Cosmic rays
✅ Answer: C) Ultraviolet radiation
Explanation: Ozone filters harmful UV-B & UV-C radiation.
Q22. Which international agreement aims to reduce ozone depletion?
A) Kyoto Protocol
B) Montreal Protocol
C) Paris Agreement
D) Rio Declaration
✅ Answer: B) Montreal Protocol
Explanation: Montreal Protocol (1987) phased out CFCs & ozone-depleting chemicals.
Q23. Which international agreement aims to reduce greenhouse gas emissions?
A) Montreal Protocol
B) Kyoto Protocol
C) Geneva Convention
D) Vienna Convention
✅ Answer: B) Kyoto Protocol
Explanation: Kyoto Protocol (1997) → commitment to reduce CO₂ emissions.
Q24. Acid rain is mainly caused by:
A) CO₂ and O₃
B) SO₂ and NOₓ
C) CH₄ and CO
D) H₂S and NH₃
✅ Answer: B) SO₂ and NOₓ
Explanation: They form H₂SO₄ and HNO₃ in atmosphere → acid rain.
Q25. Biomagnification refers to:
A) Increase in population size
B) Accumulation of pollutants at higher trophic levels
C) Increase in primary productivity
D) Growth of biomass
✅ Answer: B) Accumulation of pollutants
Explanation: Non-degradable pollutants (e.g., DDT, mercury) concentrate in higher trophic levels.
🌍 Ecology MCQs – Part 2 (Q26–Q50)
Q26. Which succession starts on bare rock surfaces with no soil?
A) Primary succession
B) Secondary succession
C) Climax succession
D) Retrogressive succession
✅ Answer: A) Primary succession
Explanation: Primary succession starts on bare surfaces (rocks, lava) without soil. Secondary succession occurs where soil is already present.
Q27. The pioneer species in primary succession on bare rock are usually:
A) Mosses
B) Lichens
C) Ferns
D) Grasses
✅ Answer: B) Lichens
Explanation: Lichens break down rock and form soil → first colonizers.
Q28. The stable, final stage of succession is called:
A) Seral stage
B) Climax community
C) Transitional stage
D) Pioneer community
✅ Answer: B) Climax community
Explanation: Climax community = stable, self-sustaining, long-term vegetation.
Q29. The removal of vegetation by forest fire leads to which succession?
A) Primary
B) Secondary
C) Climax
D) Retrogressive
✅ Answer: B) Secondary succession
Explanation: Soil remains intact, so succession restarts quickly.
Q30. Which ecological pyramid can be inverted?
A) Energy pyramid
B) Pyramid of numbers and biomass
C) Pyramid of productivity
D) All pyramids
✅ Answer: B) Numbers and biomass
Explanation: In aquatic ecosystems, biomass pyramid may be inverted (small phytoplankton biomass supports large zooplankton). Energy pyramid is always upright.
Q31. The interaction where one species is harmed and the other is unaffected is:
A) Commensalism
B) Amensalism
C) Mutualism
D) Predation
✅ Answer: B) Amensalism
Explanation: Example: Penicillium secretes antibiotic inhibiting bacteria, Penicillium unaffected.
Q32. The process of species evolving in response to each other is called:
A) Convergent evolution
B) Divergent evolution
C) Coevolution
D) Adaptive radiation
✅ Answer: C) Coevolution
Explanation: Bees and flowers, predator–prey → coevolution.
Q33. Which is NOT a greenhouse gas?
A) CO₂
B) CH₄
C) N₂
D) N₂O
✅ Answer: C) N₂
Explanation: Nitrogen gas is inert; it is not a greenhouse gas.
Q34. Which country hosted the first Earth Summit in 1992?
A) USA
B) Brazil
C) India
D) France
✅ Answer: B) Brazil (Rio de Janeiro)
Explanation: The Rio Earth Summit (1992) focused on sustainable development.
Q35. Biodiversity hotspots are areas that have:
A) Low species richness
B) High endemism and high species richness
C) Only tropical climate
D) Only endangered species
✅ Answer: B)
Explanation: Hotspots = high species richness + high endemism + threat.
Q36. India is part of how many global biodiversity hotspots?
A) 1
B) 2
C) 3
D) 4
✅ Answer: C) 3
Explanation: India has Indo-Burma, Himalaya, Indo-Malayan (Indo-Burma) & Indo-Malayan (Indo-Malayan-Sunda). Correct count = Himalaya, Indo-Burma, Indo-Malayan-Sunda (Indo-Malayan) = 3.
Q37. Which Indian law aims to protect biodiversity?
A) Environment Protection Act (1986)
B) Wildlife Protection Act (1972)
C) Forest Conservation Act (1980)
D) Biodiversity Act (2002)
✅ Answer: D) Biodiversity Act (2002)
Explanation: Biodiversity Act (2002) conserves biological diversity and sustainable use.
Q38. The Ramsar Convention is related to:
A) Climate change
B) Wetland conservation
C) Desertification
D) Marine pollution
✅ Answer: B) Wetland conservation
Explanation: Ramsar Convention (1971, Iran) protects wetlands of international importance.
Q39. Which is the most productive ecosystem?
A) Desert
B) Open ocean
C) Estuary
D) Tundra
✅ Answer: C) Estuary
Explanation: Estuaries have high nutrient input → highest productivity.
Q40. The World Wildlife Fund (WWF) symbol is:
A) Lion
B) Tiger
C) Panda
D) Elephant
✅ Answer: C) Panda
Explanation: WWF logo = giant panda.
Q41. Which of the following is an in-situ conservation method?
A) Zoological park
B) Seed bank
C) National park
D) Gene bank
✅ Answer: C) National park
Explanation: In-situ = conserve in natural habitat (national parks, sanctuaries). Ex-situ = zoos, gene banks.
Q42. Which of the following is an ex-situ conservation method?
A) Wildlife sanctuary
B) Sacred groves
C) Botanical garden
D) Biosphere reserve
✅ Answer: C) Botanical garden
Explanation: Ex-situ = conservation outside natural habitat.
Q43. The largest biosphere reserve in India is:
A) Nanda Devi
B) Nilgiri
C) Sundarbans
D) Gulf of Mannar
✅ Answer: B) Nilgiri
Explanation: Nilgiri (Karnataka–Tamil Nadu–Kerala) is the largest biosphere reserve in India.
Q44. Which is the largest terrestrial biome on Earth?
A) Tropical rainforest
B) Tundra
C) Taiga (boreal forest)
D) Desert
✅ Answer: C) Taiga (boreal forest)
Explanation: Taiga covers largest land area → subarctic coniferous forests.
Q45. The greenhouse effect is primarily due to absorption of:
A) UV radiation
B) Infrared radiation
C) X-rays
D) Cosmic rays
✅ Answer: B) Infrared radiation
Explanation: Greenhouse gases trap infrared heat radiated from Earth’s surface.
Q46. Which biome is characterized by permafrost?
A) Desert
B) Tundra
C) Taiga
D) Grassland
✅ Answer: B) Tundra
Explanation: Tundra has frozen subsoil (permafrost), low vegetation.
Q47. The species used as a symbol for a habitat’s health is called:
A) Endemic species
B) Keystone species
C) Indicator species
D) Pioneer species
✅ Answer: C) Indicator species
Explanation: Indicator species signal ecosystem health (e.g., lichens for air quality).
Q48. Which species has a disproportionately large impact on its ecosystem?
A) Invasive species
B) Keystone species
C) Rare species
D) Endangered species
✅ Answer: B) Keystone species
Explanation: Keystone species (e.g., sea otter) control ecosystem balance.
Q49. Which biome is known as the “breadbasket of the world”?
A) Grasslands
B) Deserts
C) Tundra
D) Taiga
✅ Answer: A) Grasslands
Explanation: Grasslands → fertile soils, ideal for grain cultivation.
Q50. Which ecological term refers to the variety of genes, species, and ecosystems in an area?
A) Productivity
B) Biodiversity
C) Biomass
D) Biome
✅ Answer: B) Biodiversity
Explanation: Biodiversity includes genetic diversity, species diversity, ecosystem diversity.
🌍 Ecology MCQs – Part 3 (Q51–Q75)
Q51. Which of the following is a density-dependent factor regulating population growth?
A) Earthquake
B) Flood
C) Predation
D) Drought
✅ Answer: C) Predation
Explanation: Density-dependent = effect increases with population size (predation, competition, disease). Natural disasters are density-independent.
Q52. Logistic growth curve of a population is:
A) J-shaped
B) S-shaped
C) Straight line
D) Exponential
✅ Answer: B) S-shaped
Explanation: Logistic growth = S-shaped curve, slows as population approaches carrying capacity (K).
Q53. Exponential population growth occurs when:
A) Resources are unlimited
B) Carrying capacity is reached
C) Mortality equals natality
D) Resources are limiting
✅ Answer: A) Resources are unlimited
Explanation: Exponential growth = J-shaped curve in absence of limiting factors.
Q54. The maximum population size that an environment can support is called:
A) Biotic potential
B) Natality rate
C) Carrying capacity
D) Survivorship
✅ Answer: C) Carrying capacity
Explanation: Carrying capacity (K) = sustainable population limit based on resources.
Q55. Which survivorship curve represents humans?
A) Type I (low mortality until old age)
B) Type II (constant mortality)
C) Type III (high juvenile mortality)
D) None of the above
✅ Answer: A) Type I
Explanation: Humans show low mortality early, high mortality late.
Q56. Which survivorship curve is common in oysters, frogs, and plants with many offspring?
A) Type I
B) Type II
C) Type III
D) Type IV
✅ Answer: C) Type III
Explanation: High juvenile mortality, few survive to adulthood.
Q57. The ecological principle that “two species competing for the same niche cannot coexist indefinitely” is known as:
A) Hardy–Weinberg principle
B) Competitive exclusion principle
C) Resource partitioning
D) Gause’s law
✅ Answer: B) Competitive exclusion principle
Explanation: Proposed by Gause, one species outcompetes the other unless they partition resources.
Q58. The relationship between cuckoo and crow is:
A) Mutualism
B) Brood parasitism
C) Commensalism
D) Amensalism
✅ Answer: B) Brood parasitism
Explanation: Cuckoo lays eggs in crow’s nest; crow raises chicks → cuckoo benefits, crow harmed.
Q59. Species that invade new ecosystems and outcompete native species are called:
A) Indicator species
B) Keystone species
C) Invasive species
D) Endemic species
✅ Answer: C) Invasive species
Explanation: E.g., water hyacinth, lantana.
Q60. The study of population size, growth, density, and distribution is called:
A) Community ecology
B) Autecology
C) Synecology
D) Population ecology
✅ Answer: D) Population ecology
Explanation: Population ecology = study of populations and their dynamics.
Q61. The branch of ecology dealing with individual species’ relationships with environment is:
A) Autecology
B) Synecology
C) Paleoecology
D) Genecology
✅ Answer: A) Autecology
Explanation: Autecology = single species, Synecology = communities.
Q62. Which of the following is a K-selected species?
A) Bacteria
B) Housefly
C) Elephant
D) Dandelion
✅ Answer: C) Elephant
Explanation: K-strategists = long life span, few offspring, parental care.
Q63. Which of the following is an r-selected species?
A) Elephant
B) Tiger
C) Cockroach
D) Human
✅ Answer: C) Cockroach
Explanation: r-strategists = short life, many offspring, little parental care.
Q64. A biome characterized by annual rainfall <25 cm is:
A) Desert
B) Grassland
C) Savanna
D) Taiga
✅ Answer: A) Desert
Explanation: Arid zones with <25 cm rainfall.
Q65. Plants growing in saline soils are called:
A) Hydrophytes
B) Xerophytes
C) Halophytes
D) Epiphytes
✅ Answer: C) Halophytes
Explanation: Halophytes tolerate saline conditions (e.g., mangroves).
Q66. Plants that grow in deserts with adaptations like CAM photosynthesis are called:
A) Xerophytes
B) Epiphytes
C) Mesophytes
D) Halophytes
✅ Answer: A) Xerophytes
Explanation: Xerophytes adapt to low water availability.
Q67. Epiphytes obtain water and nutrients from:
A) Soil directly
B) Host xylem
C) Air and rain
D) Host phloem
✅ Answer: C) Air and rain
Explanation: Epiphytes (orchids, mosses) grow on other plants but are not parasitic.
Q68. Which gas contributes most to acid rain besides SO₂?
A) CO₂
B) NOₓ
C) O₃
D) CH₄
✅ Answer: B) NOₓ
Explanation: NO₂ + SO₂ → nitric and sulfuric acid in rain.
Q69. Ozone hole formation is mainly due to:
A) CO₂ emissions
B) Methane emissions
C) CFCs (chlorofluorocarbons)
D) SO₂ emissions
✅ Answer: C) CFCs
Explanation: CFCs release Cl radicals → destroy ozone molecules.
Q70. Which of the following is a renewable resource?
A) Petroleum
B) Natural gas
C) Coal
D) Solar energy
✅ Answer: D) Solar energy
Explanation: Renewable = naturally replenished (solar, wind, water).
Q71. In the nitrogen cycle, ammonification refers to:
A) Conversion of N₂ into ammonia
B) Conversion of organic nitrogen into ammonia
C) Conversion of nitrate into nitrogen gas
D) Conversion of ammonia into nitrite
✅ Answer: B)
Explanation: Decomposers convert organic matter → NH₃.
Q72. The process of converting atmospheric nitrogen into ammonia is called:
A) Nitrification
B) Denitrification
C) Nitrogen fixation
D) Assimilation
✅ Answer: C) Nitrogen fixation
Explanation: Carried out by Rhizobium, Azotobacter, lightning.
Q73. The process of converting nitrates into nitrogen gas is called:
A) Nitrification
B) Denitrification
C) Ammonification
D) Nitrogen fixation
✅ Answer: B) Denitrification
Explanation: Pseudomonas converts NO₃⁻ → N₂.
Q74. Which gas is both a greenhouse gas and involved in ozone layer depletion?
A) CO₂
B) CH₄
C) N₂O
D) O₂
✅ Answer: C) N₂O
Explanation: Nitrous oxide is a greenhouse gas and participates in ozone destruction.
Q75. The energy flow in an ecosystem is:
A) Cyclic
B) Linear, unidirectional
C) Reversible
D) Equilibrium
✅ Answer: B) Linear, unidirectional
Explanation: Energy flows from sun → producers → consumers → decomposers, not recycled.
🌍 Ecology MCQs – Part 4 (Q76–Q100)
Q76. Which organisms form the base of aquatic food chains?
A) Zooplankton
B) Phytoplankton
C) Fish
D) Benthos
✅ Answer: B) Phytoplankton
Explanation: Primary producers in aquatic ecosystems are microscopic algae (phytoplankton).
Q77. The species that dominates in a community is called:
A) Endemic species
B) Dominant species
C) Keystone species
D) Rare species
✅ Answer: B) Dominant species
Explanation: Dominant species are most abundant, influence community structure strongly.
Q78. Ecotone refers to:
A) The stable climax community
B) Transitional zone between two ecosystems
C) Area of high endemism
D) Area with only invasive species
✅ Answer: B) Transitional zone
Explanation: Ecotone = transition between two ecosystems (e.g., grassland–forest boundary).
Q79. Edge effect is seen in:
A) Interior of forests
B) Ecotones
C) Deep oceans
D) Deserts
✅ Answer: B) Ecotones
Explanation: Ecotones often have greater species diversity due to edge effect.
Q80. The species richness is higher in:
A) Temperate regions
B) Polar regions
C) Tropical regions
D) Desert regions
✅ Answer: C) Tropical regions
Explanation: Tropics have stable climate + high productivity → maximum biodiversity.
Q81. The productivity of oceans is low because:
A) Light penetrates only the upper layers
B) Nutrient availability is low
C) Both A and B
D) Ocean water has no producers
✅ Answer: C) Both A and B
Explanation: Low nutrients + light limitation → low productivity in open oceans.
Q82. Which is the main cause of species extinction today?
A) Overhunting
B) Habitat destruction
C) Climate change alone
D) Natural disasters
✅ Answer: B) Habitat destruction
Explanation: Deforestation, urbanization, agriculture cause maximum species loss.
Q83. Red Data Book provides information about:
A) Forest types
B) Endangered species
C) Soil fertility
D) Genetic resources
✅ Answer: B) Endangered species
Explanation: Published by IUCN, lists threatened and endangered species.
Q84. Which biome is characterized by coniferous trees and long winters?
A) Tundra
B) Desert
C) Taiga
D) Grassland
✅ Answer: C) Taiga (boreal forest)
Explanation: Taiga = cold coniferous forests of subarctic regions.
Q85. The layer of atmosphere where ozone is found is:
A) Troposphere
B) Stratosphere
C) Mesosphere
D) Thermosphere
✅ Answer: B) Stratosphere
Explanation: Ozone layer lies in stratosphere (~15–35 km altitude).
Q86. Which Indian project was launched to protect tigers?
A) Project Elephant
B) Project Tiger
C) Wildlife Act 1972
D) MAB Programme
✅ Answer: B) Project Tiger
Explanation: Project Tiger (1973) aimed to conserve tiger habitats.
Q87. Which gas is released in the highest quantity during decomposition of organic matter?
A) Oxygen
B) Methane
C) Carbon dioxide
D) Nitrous oxide
✅ Answer: C) Carbon dioxide
Explanation: CO₂ is the main product of aerobic decomposition.
Q88. The soil layer rich in organic matter is called:
A) A-horizon
B) B-horizon
C) C-horizon
D) Bedrock
✅ Answer: A-horizon
Explanation: Topsoil (A-horizon) contains humus and nutrients.
Q89. The maximum biomass is found in which trophic level of an energy pyramid?
A) Producers
B) Primary consumers
C) Secondary consumers
D) Tertiary consumers
✅ Answer: A) Producers
Explanation: Producers have maximum biomass, base of food pyramid.
Q90. Which organisms act as decomposers in ecosystems?
A) Herbivores
B) Carnivores
C) Fungi and bacteria
D) Plants
✅ Answer: C) Fungi and bacteria
Explanation: Decomposers recycle nutrients by breaking down dead matter.
Q91. The process of nutrient enrichment in lakes leading to algal blooms is called:
A) Bioremediation
B) Eutrophication
C) Biomagnification
D) Desertification
✅ Answer: B) Eutrophication
Explanation: Excess nutrients → algal blooms → oxygen depletion.
Q92. Which aquatic biome has the highest productivity?
A) Open ocean
B) Estuaries
C) Coral reefs
D) Lakes
✅ Answer: C) Coral reefs
Explanation: Coral reefs = most productive aquatic ecosystems.
Q93. Which renewable energy source is derived from organic matter?
A) Wind energy
B) Solar energy
C) Biomass energy
D) Hydroelectric power
✅ Answer: C) Biomass energy
Explanation: Biomass (wood, dung, crop residue) → renewable fuel.
Q94. Which ecological succession occurs in abandoned croplands?
A) Primary succession
B) Secondary succession
C) Retrogressive succession
D) Climax succession
✅ Answer: B) Secondary succession
Explanation: Soil is present, so secondary succession begins quickly.
Q95. Which international treaty focuses on climate change?
A) Montreal Protocol
B) Kyoto Protocol
C) Ramsar Convention
D) CITES
✅ Answer: B) Kyoto Protocol
Explanation: Kyoto Protocol (1997) aimed at reducing greenhouse gases.
Q96. Which ecological term describes species unique to a particular geographic area?
A) Exotic species
B) Invasive species
C) Endemic species
D) Keystone species
✅ Answer: C) Endemic species
Explanation: Endemics are restricted to specific regions only.
Q97. Which conservation strategy involves protecting species outside their natural habitat?
A) In-situ conservation
B) Ex-situ conservation
C) Biosphere reserve
D) National park
✅ Answer: B) Ex-situ conservation
Explanation: Zoos, botanical gardens, seed/gene banks are ex-situ methods.
Q98. Which Indian biosphere reserve is recognized as a UNESCO World Heritage Site?
A) Nanda Devi
B) Sundarbans
C) Nilgiri
D) Gulf of Mannar
✅ Answer: B) Sundarbans
Explanation: Sundarbans mangrove forest (home of tigers) is UNESCO-recognized.
Q99. Which is the primary source of energy for Earth’s ecosystems?
A) Wind
B) Water
C) Solar energy
D) Fossil fuels
✅ Answer: C) Solar energy
Explanation: Sunlight drives photosynthesis and most ecosystems.
Q100. The best overall measure of ecosystem health is:
A) Biomass
B) Biodiversity
C) Nutrient cycles
D) Population size
✅ Answer: B) Biodiversity
Explanation: High biodiversity = stable, resilient, healthy ecosystem.
Ecology MCQs with explanations, solved ecology multiple choice questions for NEET, CBSE ICSE objective ecology questions, ecology MCQs for CUET and CSIR NET, important ecology questions for GATE and DBT BET JRF, ecology multiple choice questions for USMLE and PLAB, practice ecology MCQs for AMC licensing exams, solved ecology questions for SAT Biology Subject Test, GRE Biology Subject Test ecology MCQs, ecology multiple choice questions for BMAT and IMAT exams
