NEET Topic-wise & A
Topic 1: ORGANISM AND ITS ENVIRONMENT
NEET: Previous Years Questions
01. Assertion (A): A person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations.
Reason (R): Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen.
In the light of the above statements, choose the correct answer from the options given below.
(1) Both (A) and (R) are true and (R) is the correct explanation of (A)
(2) Both (A) and (R) are true but (R) is not the correct explanation of (A)
(3) (A) is true but (R) is false
(4) (A) is false but (R) is true (NEET 2021)
✅ (1) Both (A) and (R) are true and (R) is the correct explanation of (A)
02. Match List - I with List - II.
Choose the correct answer from the options given below.
(a) (b) (c) (d)
(1) (iv) (ii) (iii) (i)
(2) (iv) (i) (iii) (ii)
(3) (iv) (i) (ii) (iii)
(4) (iv) (iii) (ii) (i) (NEET 2021)
✅ (3) (iv) (i) (ii) (iii)
03. Niche is
(1) all the biological factors in the organism’s environment
(2) the physical space where an organism lives
(3) the range of temperature that the organism needs to live
(4) the functional role played by the organism where it lives (NEET 2018)
✅ (4) the functional role played by the organism where it lives
04. Plants which produce characteristic pneumatophores and show vivipary belong to
(1) halophytes
(2) psammophytes
(3) hydrophytes
(4) mesophytes (NEET 2017)
✅ (1) halophytes
05. Presence of plants arranged into well defined vertical layers depending on their height can be seen best in
(1) tropical rainforest
(2) grassland
(3) temperate forest
(4) tropical savannah (NEET 2017)
✅ (1) tropical rainforest
Model Questions
06. Ecology is the study of
(1) Biotic and abiotic factors in environment.
(2) Interactions among organisms and between the organism and its physical environment.
(3) Interactions of organisms with their abiotic environment.
(4) Environment and the biotic factors in it.
✅ (2) Interactions among organisms and between the organism and its physical environment.
07. Ecology is concerned with 4 levels of biological organization. They are
(1) Organisms, populations, communities & biomes.
(2) Cells, tissues, organs and organ system.
(3) Species, Populations, Ecosystems & Biomes.
(4) Autotrophs, herbivores, carnivores & decomposers.
✅ (1) Organisms, populations, communities & biomes.
08. Physiological ecology is the study of
(1) Adaptation of an organism to environments in terms of survival and reproduction.
(2) Ecology at the organismic level.
(3) Behaviour of organisms.
(4) Both (1) & (2).
✅ (4) Both (1) & (2).
09. Select the false statement from the following.
(1) Pathogens, parasites, predators, competitors etc. belong to biotic components.
(2) Water, light, temperature, soil etc. belong to physico-chemical components.
(3) Temperature gradually decreases from equator towards the poles and increases from plains to mountain tops.
(4) Temperature ranges from subzero levels in polar areas & high altitudes to >50°C in tropical deserts.
✅ (3) Temperature gradually decreases from equator towards the poles and increases from plains to mountain tops.
10. Odd one out.
(1) Pathogens
(2) Water
(3) Soil
(4) Oxygen
✅ (1) Pathogens
11. The most ecologically relevant environmental factor is
(1) Light
(2) Temperature
(3) Soil
(4) Water
✅ (2) Temperature
12. The given figure represents biome distribution with respect to annual temperature and precipitation. What do A, B, C, D, E & F represent?
(1) A= Grassland, B= Desert, C= Temperate forest, D= Tropical forest, E= Coniferous forest, F= Arctic and Alpine tundra
(2) A= Arctic and Alpine tundra, B= Coniferous forest, C= Tropical forest, D= Temperate forest, E= Grassland, F= Desert
(3) A= Desert, B= Grassland, C= Tropical forest, D= Temperate forest, E= Coniferous forest, F= Arctic and Alpine tundra
(4) A= Tropical forest, B= Arctic and Alpine tundra, C= Desert, D= Temperate forest, E= Coniferous forest, F= Grassland
✅ (3) A= Desert, B= Grassland, C= Tropical forest, D= Temperate forest, E= Coniferous forest, F= Arctic and Alpine tundra
13. Select the false statement.
(1) Average temperature in thermal springs & deep-sea hydrothermal vents is above 100°C.
(2) Mango trees cannot grow in temperate countries like Canada, Germany etc.
(3) There is no Snow leopard in Kerala forests.
(4) Tuna fishes are enormous beyond tropical latitudes in the ocean.
✅ (4) Tuna fishes are enormous beyond tropical latitudes in the ocean.
14. Organisms that can tolerate only a narrow range of temperatures are called
(1) Eurythermal
(2) Stenothermal
(3) Euryhaline
(4) Stenohaline
✅ (2) Stenothermal
15. The second most important abiotic factor is
(1) Water
(2) Air
(3) Soil
(4) Temperature
✅ (1) Water
16. The salt concentration or salinity in parts per thousand is
(1) Less than 15 in inland waters, 30-35 the sea and greater than 120 in some hypersaline lagoons.
(2) Less than 35 in inland waters, 80-85 the sea and greater than 100 in some hypersaline lagoons.
(3) Less than 25 in inland waters, 60-65 the sea and greater than 150 in some hypersaline lagoons.
(4) Less than 5 in inland waters, 30-35 the sea and greater than 100 in some hypersaline lagoons.
✅ (4) Less than 5 in inland waters, 30-35 the sea and greater than 100 in some hypersaline lagoons.
17. Select the wrong statement.
(1) Many animals use the diurnal and seasonal variations in light intensity and photoperiod for timing their foraging, reproductive & migratory activities.
(2) > 500 m deep in the oceans, the environment is dark and there is no solar energy available.
(3) The spectral quality of solar radiation is not important for life.
(4) Not all the colour components of the visible spectrum are available for marine plants.
✅ (3) The spectral quality of solar radiation is not important for life.
18. The vegetation & animals in an area are determined by
(1) Soil composition, grain size & aggregation
(2) pH of soil
(3) Mineral composition & topography
(4) All the above
✅ (4) All the above
19. Organisms maintain a constant internal environment despite varying external environmental conditions. It is called
(1) Haemostasis
(2) Homeostasis
(3) Homeothermy
(4) Poikilothermy
✅ (2) Homeostasis
20. Sweating is a way of
(1) Regulate
(2) Conform
(3) Suspend
(4) Migrate
✅ (1) Regulate
21. Given below is the diagrammatic representation of organismic response. Label A, B & C.
(1) A= Regulators, B= Conformers, C= Partial regulators
(2) A= Partial regulators, B= Conformers, C= Regulators
(3) A= Conformers, B= Regulators, C= Partial regulators
(4) A= Regulators, B= Partial regulators, C= Conformers
✅ (3) A= Conformers, B= Regulators, C= Partial regulators
22. ……… of animals and nearly all plants cannot maintain a constant internal environment.
(1) 80%
(2) 90%
(3) 99%
(4) 100%
✅ (3) 99%
23. Which one is correctly explains conformers?
(1) They can maintain a constant body temperature and a constant osmotic concentration.
(2) They can maintain a constant osmotic concentration.
(3) Their body temperature changes with the surrounding conditions.
(4) Their body temperature or water and ionic level change with the surrounding conditions.
✅ (4) Their body temperature or water and ionic level change with the surrounding conditions.
24. Thermoregulation for small animals is
(1) Energetically cheap because they have a larger surface area relative to their volume.
(2) Energetically expensive because they have a larger surface area relative to their volume.
(3) Energetically expensive because they have a smaller surface area relative to their volume.
(4) Energetically cheap because they have a smaller surface area relative to their volume.
✅ (2) Energetically expensive because they have a larger surface area relative to their volume.
25. Which of the following sets of animals have a larger surface area relative to their volume?
(1) Shrews, humming birds, rats
(2) Elephant, blue whale, giraffe
(3) Human, deer, mouse
(4) Blue whale, dinosaurs, elephant
✅ (1) Shrews, humming birds, rats
26. Which of the following is not an example for “suspend”?
(1) Formation of thick-walled spores in bacteria, fungi & lower plants.
(2) Osmoregulation of birds and mammals.
(3) Diapause of many zooplanktons.
(4) Hibernation of bears during winter.
✅ (2) Osmoregulation of birds and mammals.
27. The morphological, physiological & behavioural attribute that enables an organism to survive and reproduce in its habitat is called
(1) Regulation
(2) Adaptation
(3) Acclimatization
(4) Conformation
✅ (2) Adaptation
28. If there is no external source of water, body of kangaroo rat in North America can produce water by
(1) Fat oxidation
(2) Sugar oxidation
(3) Protein oxidation
(4) Glycogen oxidation
✅ (1) Fat oxidation
29. Which of the following is the adaptation of desert plants?
(1) Presence of thick cuticle on leaf surfaces.
(2) Their stomata are arranged in deep pits to minimise water loss through transpiration.
(3) CAM pathway that enables their stomata to remain closed during day time.
(4) All the above.
✅ (4) All the above.
30. In a warm-blooded animal species having distinct geographic populations, the limbs, ears and other appendages of the animals living in cold climates tend to be shorter than in animals of the same species living in warm climates. This is called
(1) Allen’s Rule
(2) Bergman's rule
(3) Gause's Hypothesis
(4) Gloger’s rule
✅ (1) Allen’s Rule
31. Regarding altitude sickness, which statement is false?
(1) It feels at a high-altitude place greater than 3,500 m.
(2) Its symptoms are nausea, heart palpitations & fatigue.
(3) This is due to low atmospheric pressure.
(4) Gradually, for acclimatization, the body increases the binding capacity of hemoglobin.
✅ (4) Gradually, for acclimatization, the body increases the binding capacity of hemoglobin.
Topic 2: POPULATIONS
NEET: Previous Years Questions
32. The equation of Verhulst-Pearl logistic growth is
From this equation, K indicates:
(1) Intrinsic rate of natural increase
(2) Biotic potential
(3) Carrying capacity
(4) Population density (NEET 2024)
✅ (3) Carrying capacity
33. Given below are two statements:
Statement I: Gause's competitive exclusion principle states that two closely related species competing for different resources cannot exist indefinitely.
Statement II: According to Gause's principle, during competition, the inferior will be eliminated. This may be true if resources are limiting.
In the light of the above statements, choose the correct answer from the options given below:
(1) Both Statement I and Statement II are true.
(2) Both Statement I and Statement II are false.
(3) Statement I is true but Statement II is false.
(4) Statement I is false but Statement II is true.
✅ (4) Statement I is false but Statement II is true.
34. Match List I with List II.
Choose the correct answer from the options given below:
(1) A-II, B-III, C-I, D-IV
(2) A-II, B-IV, C-I, D-III
(3) A-II, B-IV, C-III, D-I
(4) A-II, B-I, C-III, D-IV (NEET 2023)
✅ (4) A-II, B-I, C-III, D-IV
35. Given below are two statements:
Statement I: ‘Gause’s Competitive Principle’ states that two closely related species competing for the same resources cannot co-exist indefinitely and competitively inferior one will be eliminated eventually.
Statement II: In general, carnivores are more adversely affected by competition than herbivores.
In the light of the above statements, choose the correct answer from the options given below:
(1) Both Statement I and Statement II are false.
(2) Statement I is correct Statement II is false.
(3) Statement I is incorrect but Statement II is true.
(4) Both Statement I and Statement II are true. (NEET 2023)
✅ (2) Statement I is correct Statement II is false.
36. Match List I with List II:
Choose the correct answer from the options given below:
(1) A-IV, B-I, C-II, D-III
(2) A-IV, B-III, C-I, D-II
(3) A-III, B-I, C-IV, D-II
(4) A-IV, B-II, C-I, D-III (NEET 2023)
✅ (1) A-IV, B-I, C-II, D-III
37. Match List I with List II.
Choose the correct answer from the options given below.
(1) A-I, B-II, C-IV, D-III
(2) A-III, B-IV, C-I, D-II
(3) A-II, B-III, C-I, D-IV
(4) A-I, B-II, C-III, D-IV (NEET 2023)
✅ (4) A-I, B-II, C-III, D-IV
38. In the exponential growth equation, Nt = N0 ert, e represents
(1) The base of number logarithms
(2) The base of exponential logarithms
(3) The base of natural logarithms
(4) The base of geometric logarithms (NEET 2021)
✅ (3) The base of natural logarithms
39. In spite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival?
(1) Resource partitioning
(2) Competitive release
(3) Mutualism
(4) Predation (NEET 2021)
✅ (1) Resource partitioning
40. Amensalism can be represented as:
(1) Species A (-); Species B (0)
(2) Species A (+); Species B (+)
(3) Species A (-); Species B (-)
(4) Species A (+); Species B (0) (NEET 2021)
✅ (1) Species A (-); Species B (0)
41. Which of the following is not an attribute of a population?
(1) Mortality
(2) Species interaction
(3) Sex ratio
(4) Natality (NEET 2020)
✅ (2) Species interaction
42. Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their:
(1) Defence action
(2) Effect on reproduction
(3) Nutritive value
(4) Growth response (NEET 2020)
✅ (1) Defence action
43. Pinus seed cannot germinate and establish without fungal association. This is because:
(1) its embryo is immature.
(2) it has obligate association with mycorrhizae.
(3) it has very hard seed coat.
(4) its seeds contain inhibitors that prevent germination. (NEET 2019)
✅ (2) it has obligate association with mycorrhizae.
44. Natality refers to
(1) Death rate
(2) Birth rate
(3) Number of individuals leaving the habitat
(4) Number of individuals entering a habitat (NEET 2018)
✅ (2) Birth rate
45. Which one of the following population interactions is widely used in medical science for the production of antibiotics?
(1) Commensalism
(2) Mutualism
(3) Parasitism
(4) Amensalism (NEET 2018)
✅ (4) Amensalism
46. Asymptote in a logistic growth curve is obtained when
(1) K = N
(2) K > N
(3) K < N
(4) the value of ‘r’ approaches zero (NEET 2017)
✅ (1) K = N
47. Mycorrhizae are the example of
(1) amensalism
(2) antibiosis
(3) mutualism
(4) fungistasis (NEET 2017)
✅ (3) mutualism
48. When does the growth rate of a population following the logistic model equal zero? The logistic model is given as dN/dt = rN(1–N/K)
(1) when N/K equals zero
(2) when death rate is greater than birth rate
(3) when N/K is exactly one
(4) when N nears the carrying capacity of the habitat. (NEET-I 2016)
✅ (3) when N/K is exactly one
49. Gause’s principle of competitive exclusion states that
(1) no two species can occupy the same niche indefinitely for the same limiting resources
(2) larger organisms exclude smaller ones through competition
(3) more abundant species will exclude the less abundant species through competition
(4) competition for the same resources exclude species having different food preferences (NEET-I 2016)
✅ (1) no two species can occupy the same niche indefinitely for the same limiting resources
50. It is much easier for a small animal to run uphill than for a large animal, because
(1) small animals have a lower O2 requirement
(2) the efficiency of muscles in large animals is less than in the small animals
(3) it is easier to carry a small body weight
(4) smaller animals have a higher metabolic rate (NEET-I 2016)
✅ (4) smaller animals have a higher metabolic rate
51. Which of the following is correct for r-selected species?
(1) Large number of progeny with small size
(2) Large number of progeny with large size
(3) Small number of progeny with small size
(4) Small number of progeny with large size (NEET-II 2016)
✅ (1) Large number of progeny with small size
52. If ‘+’ sign is assigned to beneficial interaction, ‘–’ sign to detrimental and ‘O’ sign to neutral interaction, then the population interaction represented by ‘+’ ‘–’ refers to
(1) mutualism
(2) amensalism
(3) commensalism
(4) parasitism (NEET-II 2016)
✅ (4) parasitism
53. The principle of competitive exclusion was stated by
(1) C. Darwin
(2) G.F. Gause
(3) Mac Arthur
(4) Verhulst and Pearl (NEET-II 2016)
✅ (2) G.F. Gause
Model Questions
54. A population is
(1) A group of organisms that live in a given geographical area, share or compete for similar resources and potentially reproduce.
(2) A group species that live in a given geographical area, share or compete for similar resources and potentially reproduce.
(3) A group of individuals of same species that live in a given geographical area, share or compete for similar resources and potentially reproduce.
(4) The number of individuals of a species per unit area or volume.
✅ (3) A group of individuals of same species that live in a given geographical area, share or compete for similar resources and potentially reproduce.
55. Population ecology is an important area of ecology as it links ecology to
(1) Population genetics & Physiology
(2) Population genetics & Evolution
(3) Population genetics & Molecular biology
(4) Population genetics & Biochemistry
✅ (2) Population genetics & Evolution
56. In a pond, there are 48 lotus plants last year and through reproduction 18 new plants are added. Then the birth rate is
(1) 0.375 offspring per lotus per year
(2) 0.17 offspring per lotus per year
(3) 0.775 offspring per lotus per year
(4) 0.3 offspring per lotus per year
✅ (1) 0.375 offspring per lotus per year
57. In the given diagram of age pyramids, P, Q & R represent
(1) P= Stable growth, Q= Expanding growth, R= Declining growth
(2) P= Declining growth, Q= Stable growth, R= Expanding growth
(3) P= Stable growth, Q= Declining growth, R= Expanding growth
(4) P= Expanding growth, Q= Stable growth, R= Declining growth
✅ (4) P= Expanding growth, Q= Stable growth, R= Declining growth
58. Population density (N) of Siberian cranes at Bharatpur wetlands in any year is
(1) > 10
(2) < 10
(3) > 100
(4) < 100
✅ (2) < 10
59. In population attributes, N represents
(1) Natality
(2) Mortality
(3) Population density
(4) Emigration
✅ (3) Population density
60. Four basic processes that fluctuate the population density are
(1) Natality, mortality, lag phase & log phase
(2) Lag phase, log phase, immigration & emigration
(3) Lag phase, migration, immigration & emigration
(4) Natality, mortality, immigration & emigration
✅ (4) Natality, mortality, immigration & emigration
61. The number of individuals of the same species that have come into the habitat from elsewhere during a given time period is called
(1) Migration
(2) Immigration
(3) Emigration
(4) None of these
✅ (2) Immigration
62. In the given figure, K, L, M & N depict the sign of
(1) K= +, L= +, M= –, N= –
(2) K= –, L= –, M= +, N= +
(3) K= +, L= –, M= +, N= –
(4) K= –, L= +, M= –, N= +
✅ (1) K= +, L= +, M= –, N= –
63. Population density increases if
(1) B+I is less than D+E
(2) B+E is more than D+I
(3) B+I is more than D+E
(4) B+E is less than D+I
✅ (3) B+I is more than D+E
64. Under normal conditions, the two important factors that influence population density are
(1) Immigration & Emigration
(2) Births & deaths
(3) Immigration & Births
(4) Emigration & deaths
✅ (2) Births & deaths
65. A biologist studied the population of rats in a barn. He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is
(1) 05
(2) Zero
(3) 10
(4) 15
✅ (2) Zero
66. Formula of growth rate for population in given time is
(1) dt/dN = rN
(2) dt/rN = dN
(3) rN/dN = dt
(4) dN/dt = rN
✅ (4) dN/dt = rN
67. Which is correctly labelled with respect to the given diagram?
(1) B: Logistic curve
(2) C: Carrying capacity
(3) C: Exponential curve
(4) A: Carrying capacity
✅ (4) A: Carrying capacity
68. Asymptote in a logistic growth curve is obtained when
(1) K = N
(2) K > N
(3) K < N
(4) Value of r approaches zero
✅ (1) K = N
69. In the equation,
what K & N denote?
(1) K = Population density at a time, N= Carrying capacity
(2) K = Intrinsic rate of natural increase, N= Carrying capacity
(3) K = Carrying capacity, N= Population density at a time
(4) K = Intrinsic rate of natural increase, N= Population density at t= 0
✅ (3) K = Carrying capacity, N= Population density at a time
70. Match the list I with list II and choose the correct option.
(1) A-4, B-3, C-1, D-2
(2) A-3, B-4, C-1, D-2
(3) A-3, B-1, C-4, D-2
(4) A-2, B-3, C-4, D-1
✅ (4) A-2, B-3, C-4, D-1
71. Which of the following is wrong statement?
(1) Populations evolve to minimize their reproductive fitness or Darwinian fitness (high r value).
(2) Under a particular set of selection pressures, organisms evolve towards the most efficient reproductive strategy.
(3) Life history traits of organisms have evolved due to limited abiotic and biotic components of the habitat.
(4) Since resources for growth for most animal populations are finite the logistic growth model is more realistic one.
✅ (1) Populations evolve to minimize their reproductive fitness or Darwinian fitness (high r value).
72. Match the following:
(1) A= 5, B= 3, C= 2, D= 1, E= 4
(2) A= 3, B= 4, C= 5, D= 2, E= 1
(3) A= 2, B= 3, C= 1, D= 5, E= 4
(4) A= 4, B= 3, C= 2, D= 5, E= 1
✅ (4) A= 4, B= 3, C= 2, D= 5, E= 1
73. Cryptic colouration of some insects & frogs is called
(1) Camouflage
(2) Bioluminescence
(3) Hibernation
(4) Metagenesis
✅ (1) Camouflage
74. Select the false statement.
(1) Monarch butterfly is distasteful to its predator bird. It is due to a special chemical acquired during its caterpillar stage by feeding on a poisonous weed.
(2) Calotropis produce highly poisonous cardiac glycosides. Therefore, cattle or goats do not eat it.
(3) Nicotine, caffeine, quinine, strychnine, opium, etc. are defenses against grazers and browsers.
(4) The goats in Galapagos Islands became extinct within a decade after Abingdon tortoise were introduced on the island.
✅ (4) The goats in Galapagos Islands became extinct within a decade after Abingdon tortoise were introduced on the island.
75. A process in which fitness of one species (‘r’ value) is significantly lower in presence of another species is called
(1) Competition
(2) Comensalism
(3) Parasitism
(4) Predation
✅ (1) Competition
76. The feeding efficiency of one species is reduced due to the presence of other species, even if resources are abundant. This is called
(1) Intraspecific competition
(2) Interference competition
(3) Interspecific competition
(4) Competitive release
✅ (2) Interference competition
77. A species, restricted to a small geographical area, expands its distributional range when the competing species is experimentally removed. It is called
(1) Competitive release
(2) Resource partitioning
(3) Interference competition
(4) Struggle for existence
✅ (1) Competitive release
78. Connell’s field experiments showed that on the rocky sea coasts of Scotland, the larger barnacle Balanus dominates intertidal area, and excludes the smaller barnacle Chathamalus from that zone. This happened due to
(1) Parasitism
(2) Predation
(3) Mutualism
(4) Competition
✅ (4) Competition
79. The principle of competitive exclusion was stated by
(1) C. Darwin
(2) G.F Gause
(3) MacArthur
(4) Verhulst and Pearl
✅ (2) G.F Gause
80. If two species compete for the same resource, they could avoid competition by choosing different times for feeding or different foraging patterns. This is called
(1) Competitive release
(2) Interference competition
(3) Resource partitioning
(4) Struggle for existence
✅ (3) Resource partitioning
81. Match the following:
(1) A= 5, B= 3, C= 2, D= 1, E= 4
(2) A= 3, B= 4, C= 5, D= 2, E= 1
(3) A= 4, B= 3, C= 2, D= 5, E= 1
(4) A= 2, B= 3, C= 1, D= 5, E= 4
✅ (3) A= 4, B= 3, C= 2, D= 5, E= 1
82. Human liver fluke depends on 2 intermediate hosts to complete its life cycle. They are
(1) Snail & Human
(2) Human & fish
(3) Snail & mosquito
(4) Snail & fish
✅ (4) Snail & fish
83. Match the organisms in column I with the organisms of column II based on their interaction of commensalism.
(1) A= 4, B= 3, C= 2, D= 1
(2) A= 3, B= 4, C= 2, D= 1
(3) A= 3, B= 4, C= 1, D= 2
(4) A= 2, B= 3, C= 4, D= 1
✅ (1) A= 4, B= 3, C= 2, D= 1
84. Which of the following associations shows mutualism?
(1) Barnacles on whale
(2) Fig and wasp
(3) Roundworms in human intestine
(4) Orchids on mango tree
✅ (2) Fig and wasp