Ecosystem NEET PYQReal NEET & AIPMT 2006–2021 questions, year-tagged, with solutions
By the RankUp team, founded by Dr. Deepak Sahu (MBBS Gold Medalist, NEET PG AIR 1731) · Updated
Every Ecosystem question from the NEET & AIPMT papers on this site (2006–2021), newest first. Each is tagged with its paper. Tap an option to check your answer and read the explanation.
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Ecosystem previous year questions
38 questions. Tap an option to check your answer.
Q1NEET 2021
In the equation GPP − R = NPP R represents :
Not quite — the answer is D.
Net primary productivity is what remains of gross primary productivity after the producers' own respiration losses are subtracted, so R stands for respiration. Radiant energy is the input that drives GPP, not something subtracted from it.
Q2NEET 2021
Which of the following statements is not correct ?
Not quite — the answer is B.
In the sea the standing biomass of phytoplankton is smaller than that of the fishes feeding on them, so the pyramid of biomass is generally inverted, not upright. The pyramid of energy is always upright and the grassland pyramid of numbers is upright, so those statements are correct.
Q3NEET 2020 · Q60
Match the trophic levels with their correct species examples in grassland ecosystem. (a) Fourth trophic level | (i) Crow (b) Second trophic level | (ii) Vulture (c) First trophic level | (iii) Rabbit (d) Third trophic level | (iv) Grass Select the correct option:
Not quite — the answer is A.
In a grassland food chain grass is the producer (first level), rabbit the primary consumer (second), crow the secondary consumer (third), and vulture the top carnivore (fourth). Hence vulture, rabbit, grass, crow is correct.
Q4NEET 2020 · Q69
In relation to Gross primary productivity and Net primary productivity of an ecosystem, which one of the following statements is correct?
Not quite — the answer is B.
NPP = GPP − R, where R is the energy used in respiration by the producers, so GPP is always greater than NPP. GPP cannot be less than or equal to NPP, because respiration losses are always present.
Q5NEET 2019 · Q137
Which of the following ecological pyramids is generally inverted ?
Not quite — the answer is D.
In the sea the standing biomass of phytoplankton is far smaller than that of the fish feeding on them, so the pyramid of biomass is inverted. The pyramid of energy can never be inverted, and the grassland pyramid of numbers is upright.
Q6NEET 2018 · Q115
What type of ecological pyramid would be obtained with the following data? Secondary consumer : 120 g Primary consumer : 60 g Primary producer : 10 g
Not quite — the answer is C.
The data are masses (biomass), and they increase from producers (10 g) to primary consumers (60 g) to secondary consumers (120 g), so the base is the narrowest level and the pyramid of biomass is inverted, as in some aquatic ecosystems. Grams are not numbers of individuals or energy units, so the other pyramid types do not fit.
Q7NEET 2017 · Q87
Which ecosystem has the maximum biomass?
Not quite — the answer is A.
Forests hold by far the largest standing biomass because of their massive woody trees. Grasslands have small herbaceous producers, and ponds and lakes have tiny phytoplankton with low standing crop.
Q8NEET 2017 · Q107
Presence of plants arranged into well defined vertical layers depending on their height can be seen best in:
Not quite — the answer is B.
Vertical stratification, with emergent trees, canopy, understorey shrubs and ground herbs, is best developed in tropical rain forests. Grasslands and savannas have mostly herbaceous layers, and temperate forests have fewer layers.
Q9NEET 2017 (Gujarati paper) · Q70
Which of the following ecologists has tried to put price-tags on nature's life support services?
Not quite — the answer is B.
Robert Constanza and his colleagues estimated the value of global ecosystem services at about US $33 trillion a year. David Tilman worked on productivity-diversity experiments, Paul Ehrlich proposed the rivet popper hypothesis, and Robert May estimated global species diversity.
Q10NEET 2017 (Gujarati paper) · Q99
The sequential events from initial stage till climax stage in a succession are called:
Not quite — the answer is B.
The entire sequence of communities that replace one another from the pioneer stage to the climax community is called a sere, and each stage is a seral stage. Nudation (formation of a bare area), migration and ecesis (establishment) are only individual steps of succession.
Q11NEET 2017 (Gujarati paper) · Q134
Which of the following statements is not true?
Not quite — the answer is B.
Detritivores feed on dead organic matter from every trophic level, including dead leaves and wood of producers, so excluding the producer level is false. Primary consumers are by definition herbivores, one organism such as a sparrow can feed at more than one trophic level, and energy decreases at each higher level.
Q12NEET 2016 Phase 2 · Q131
The primary producers of the deep-sea hydrothermal vent ecosystem are
Not quite — the answer is B.
No sunlight reaches deep-sea vents, so the producers are chemosynthetic bacteria that oxidise hydrogen sulphide and other compounds to fix carbon. Green algae and blue-green algae need light, and coral reefs are shallow-water communities.
Q13NEET 2016 Phase 1 · Q121
Which one of the following is a characteristic feature of cropland ecosystem?
Not quite — the answer is B.
A cropland is a man-made ecosystem usually dominated by a single crop variety (monoculture), so its genetic diversity is very low. Soil organisms and weeds are present, and succession is prevented by repeated cultivation.
Q14NEET 2016 Phase 1 · Q152
The term ecosystem was coined by:
Not quite — the answer is B.
A. G. Tansley coined the term ecosystem in 1935. Haeckel coined the term ecology, and Odum and Warming are known for other contributions to ecology.
Q15NEET 2016 Phase 1 · Q157
Which of the following would appear as the pioneer organisms on bare rocks?
Not quite — the answer is A.
In primary succession on bare rock (xerarch), lichens are the pioneers: they secrete acids that weather rock and form a thin soil. Mosses and liverworts follow only after some soil has formed.
Q16AIPMT 2015
Vertical distribution of different species occupying different levels in a biotic community is known as:
Not quite — the answer is C.
Stratification is the vertical layering of species in a community, e.g. trees at the top, then shrubs, then herbs and grasses in a forest. Zonation is a horizontal change of communities along a gradient, not vertical layering within one community.
Q17AIPMT 2015
In an ecosystem the rate of production of organic matter during photosynthesis is termed as:
Not quite — the answer is C.
Gross primary productivity is the rate of production of organic matter by photosynthesis. Net primary productivity is what remains after the producers' own respiratory loss is subtracted.
Q18AIPMT 2015
Secondary Succession takes place on/in:
Not quite — the answer is C.
Secondary succession begins in areas where a natural community has been destroyed but soil remains, such as a degraded, burnt or cut forest, so it is faster. Newly cooled lava, bare rock and a newly created pond have no previous community and undergo primary succession.
Q19AIPMT 2015
The mass of living material at a trophic level at a particular time is called:
Not quite — the answer is A.
Standing crop is the mass of living material present at a trophic level at a given time. Standing state is the amount of inorganic nutrients in the soil at a given time, and productivity is a rate, not a mass.
Q20AIPMT 2014
If 20 J of energy is trapped at producer level, then how much energy will be available to peacock as food in the following chain? plant → mice → snake → peacock
Not quite — the answer is D.
By the 10 percent law only about one tenth of energy passes to each next trophic level: 20 J (plant) → 2 J (mice) → 0.2 J (snake) → 0.02 J (peacock). The value 0.2 J is what the snake receives, one step short of the peacock.
Q21NEET 2013
Secondary productivity is rate of formation of new organic matter by
Not quite — the answer is C.
Secondary productivity is the rate at which consumers form new organic matter from the food they assimilate. Formation of organic matter by producers is primary productivity.
Q22NEET 2013
Which one of the following processes during decomposition is correctly described?
Not quite — the answer is A.
Fragmentation, the breaking of detritus into small particles, is carried out by detritivores such as earthworms. Humus decomposes extremely slowly, leaching carries soluble nutrients down into lower soil layers, and catabolism is enzymatic breakdown, not the last anaerobic step.
Q23AIPMT 2012 Mains
The rate of formation of new organic matter by rabbit in a grassland is called
Not quite — the answer is B.
Secondary productivity is the rate at which consumers such as a rabbit form new organic matter. Gross and net primary productivity refer only to producers (green plants).
Q24AIPMT 2012 Prelims
Identify the possible link "A" in the following food chain: Plant → insect → frog → "A" → Eagle
Not quite — the answer is D.
A cobra eats frogs and is in turn eaten by an eagle, so it fits between them. A parrot and a rabbit are herbivores that do not eat frogs, and a wolf is not normally preyed on by an eagle.
Q25AIPMT 2012 Prelims
The upright pyramid of number is absent in
Not quite — the answer is C.
In a forest, a few large trees support many herbivores (insects, birds), so the pyramid of numbers is inverted or spindle-shaped rather than upright. Grassland, pond and lake ecosystems have upright pyramids of numbers.
Q26AIPMT 2012 Prelims
Which one of the following is not a functional unit of an ecosystem?
Not quite — the answer is A.
Stratification is the vertical layering of species, a structural feature of an ecosystem. Productivity, decomposition, energy flow and nutrient cycling are the functional aspects.
Q27AIPMT 2011 Mains
Which one of the following animals may occupy more than one trophic level in the same ecosystem at the same time?
Not quite — the answer is C.
A sparrow eats grains and fruits (primary consumer) as well as insects (secondary consumer), so it occupies two trophic levels at once. A goat is strictly herbivorous and a lion strictly a top carnivore; a frog feeds mainly on insects.
Q28AIPMT 2011 Mains
Both, hydrarch and xerarch successions lead to
Not quite — the answer is C.
Hydrarch succession moves from water towards drier conditions and xerarch from dry towards wetter conditions, so both end in a mesic (medium water) climax. Neither ends in extreme wet or xeric conditions.
Q29AIPMT 2011 Mains
The breakdown of detritus into smaller particles by earthworm is a process called
Not quite — the answer is D.
Breaking detritus into smaller particles by detritivores such as earthworms is fragmentation. Humification is the formation of humus, and mineralisation is the later release of inorganic nutrients from humus.
Q30AIPMT 2011 Prelims
Of the total incident solar radiation the proportion of PAR is
Not quite — the answer is D.
Of the total incident solar radiation, less than 50 percent is photosynthetically active radiation (PAR, 400–700 nm). Plants capture only about 2–10 percent of this PAR.
Q31AIPMT 2011 Prelims
Mass of living matter at a trophic level in an area at any time is called
Not quite — the answer is B.
Each trophic level holds a certain mass of living material at a given time, called the standing crop, measured as biomass or number per unit area. Standing state refers to the amount of nutrients in the soil, and detritus and humus are dead organic matter.
Q32AIPMT 2011 Prelims
Which one of the following statements for pyramid of energy is incorrect, whereas the remaining three are correct?
Not quite — the answer is D.
Because energy is lost at each transfer, the energy at each trophic level is always less than at the level below. The pyramid of energy is therefore always upright with a broad base and can never be inverted.
Q33AIPMT 2010 Prelims · Q170
The biomass available for consumption by the herbivores and the decomposers is called
Not quite — the answer is B.
Net primary productivity is gross primary productivity minus what plants lose in respiration. It is the biomass actually available to herbivores and decomposers. Standing crop is the biomass present at a given moment, not the rate of production available to consumers.
Q34AIPMT 2010 Prelims · Q171
Which one of the following is one of the characteristics of a biological community?
Not quite — the answer is B.
Stratification, the vertical layering of different species such as trees, shrubs and herbs, is a structural feature of a community. Sex ratio, natality and mortality are attributes of a single-species population.
Q35AIPMT 2009 Prelims · Q143
Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?
Not quite — the answer is A.
Fish in a pond may feed on plants or algae (primary consumer) as well as on zooplankton or smaller fish (secondary or higher consumer), so they occupy several trophic levels. Phytoplankton are only producers and zooplankton are mainly primary consumers.
Q36AIPMT 2008 Prelims · Q175
Consider the following statements concerning food chains (a) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation (b) Removal of most of the carnivores resulted in an increased population of deers (c) The length of food chains is generally limited to 3-4 trophic levels due to energy loss (d) The length of food chains may vary from 2 to 8 trophic levels. Which two of the above statements are correct?
Not quite — the answer is B.
Removing predators lets herbivores like deer multiply, and because only about 10% of energy passes to each higher level, food chains are usually limited to 3-4 trophic levels. Removing tigers would reduce vegetation through overgrazing rather than increase it, and 8-level chains do not occur.
Q37AIPMT 2007 Prelims · Q168
Which one of the following ecosystem types has the highest annual net primary productivity?
Not quite — the answer is D.
Tropical rain forests have high temperature, abundant rainfall and year-round sunlight, giving the highest net primary productivity among terrestrial ecosystems. Deciduous and temperate forests have seasons that limit growth.
Q38AIPMT 2006 Prelims · Q116
Which one of the following is not used for construction of ecological pyramids ?
Not quite — the answer is D.
Pyramids are built from numbers, biomass measured as dry weight, or energy flow. Fresh weight is not used because water content varies a lot between organisms and would distort the biomass comparison.
How often Ecosystem came up
Questions from this chapter in each paper on this site.
- NEET 2021: 2
- NEET 2020: 2
- NEET 2019: 1
- NEET 2018: 1
- NEET 2017: 2
- NEET 2017 (Gujarati paper): 3
- NEET 2016 Phase 2: 1
- NEET 2016 Phase 1: 3
- AIPMT 2015: 4
- AIPMT 2014: 1
- NEET 2013: 2
- AIPMT 2012 Mains: 1
- AIPMT 2012 Prelims: 3
- AIPMT 2011 Mains: 3
- AIPMT 2011 Prelims: 3
- AIPMT 2010 Prelims: 2
- AIPMT 2009 Prelims: 1
- AIPMT 2008 Prelims: 1
- AIPMT 2007 Prelims: 1
- AIPMT 2006 Prelims: 1
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