Organisms and Populations NEET PYQReal NEET & AIPMT 2005–2021 questions, year-tagged, with solutions
By the RankUp team, founded by Dr. Deepak Sahu (MBBS Gold Medalist, NEET PG AIR 1731) · Updated
Every Organisms and Populations question from the NEET & AIPMT papers on this site (2005–2021), newest first. Each is tagged with its paper. Tap an option to check your answer and read the explanation.
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Organisms and Populations previous year questions
30 questions. Tap an option to check your answer.
Q1NEET 2021
Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival ?
Not quite — the answer is A.
Competing species can coexist by resource partitioning, using the same resource in different ways, places or times, as MacArthur showed for warblers feeding in different parts of the same tree. Competitive release is the expansion of a species once its competitor is removed, not a coexistence mechanism.
Q2NEET 2021
Amensalism can be represented as :
Not quite — the answer is A.
In amensalism one species is harmed while the other is neither benefited nor harmed, giving the (−, 0) pattern. The (+, 0) pattern is commensalism and (+, +) is mutualism.
Q3NEET 2021
In the exponential growth equation Nt = N₀eʳᵗ, e represents :
Not quite — the answer is C.
In the exponential growth equation Nt = N₀eʳᵗ, e is the base of natural logarithms, about 2.71828. The other phrases are not standard names of a logarithm base.
Q4NEET 2020 · Q1
Which of the following is not an attribute of a population?
Not quite — the answer is D.
Sex ratio, natality and mortality are attributes of a population as a group, not of single individuals. Species interaction (predation, competition, mutualism) describes how different species affect each other, so it is a feature of the community, not an attribute of one population.
Q5NEET 2018 · Q111
Natality refers to
Not quite — the answer is B.
Natality is the number of births in a population during a given period, i.e. the birth rate, and it adds to population density. Individuals leaving the habitat is emigration, individuals entering is immigration, and the death rate is mortality.
Q6NEET 2018 · Q114
Niche is
Not quite — the answer is D.
An ecological niche is the functional role of an organism in its habitat, including the range of conditions it tolerates and the resources it uses. The physical space where it lives is its habitat, and a temperature range alone is only one dimension of the niche.
Q7NEET 2018 · Q156
In a growing population of a country,
Not quite — the answer is C.
A growing (expanding) population has a broad-based, triangular age pyramid, meaning pre-reproductive individuals outnumber reproductive ones. Roughly equal numbers give a bell-shaped, stable pyramid, and fewer pre-reproductive individuals give an urn-shaped, declining one.
Q8NEET 2017 · Q72
Mycorrhizae are the example of:
Not quite — the answer is D.
In mycorrhiza the fungus absorbs mineral nutrients such as phosphorus for the plant, and the plant supplies the fungus with carbohydrates, so both partners benefit: mutualism. Amensalism harms one partner without affecting the other.
Q9NEET 2017 · Q82
Asymptote in a logistic growth curve is obtained when:
Not quite — the answer is B.
In logistic growth dN/dt = rN(K − N)/K, so growth stops and the curve flattens into the asymptote when population density N reaches the carrying capacity K. The intrinsic rate r stays the same; it is the (K − N)/K term that falls to zero.
Q10NEET 2017 (Gujarati paper) · Q88
In a hypothetical population of 100 individual having 'r' = 0.5/female/year, what will be the population size in 6 years (with e = 2.72) showing exponential rate of growth?
Not quite — the answer is C.
Exponential growth gives Nₜ = N₀e^(rt) = 100 × e^(0.5 × 6) = 100 × e³ = 100 × (2.72)³ ≈ 100 × 20.12 ≈ 2012. Using rt = 2 instead (100 × 2.72² ≈ 739) is the common slip.
Q11NEET 2016 Phase 2 · Q132
Which of the following is correct for r-selected species?
Not quite — the answer is A.
r-selected species such as oysters and many insects produce very many small offspring with little parental care. Producing few, large, well-cared-for offspring is the K-selected strategy.
Q12NEET 2016 Phase 2 · Q133
If '+' sign is assigned to beneficial interaction, '–' sign to detrimental and '0' sign to neutral interaction, then the population interaction represented by '+' '–' refers to
Not quite — the answer is D.
In parasitism the parasite benefits (+) while the host is harmed (–). Mutualism is +/+, commensalism is +/0 and amensalism is –/0; predation is also +/– but is not offered.
Q13NEET 2016 Phase 1 · Q91
Gause's principle of competitive exclusion states that:
Not quite — the answer is C.
Gause's principle says two closely related species competing for the same limiting resource cannot coexist indefinitely in the same niche; the competitively inferior one is eventually eliminated. It is not about abundance or body size, and species with different food preferences do not compete for the same resource at all.
Q14AIPMT 2014
A location with luxuriant growth of lichens on the trees indicates that the:
Not quite — the answer is C.
Lichens are very sensitive to sulphur dioxide and do not grow in polluted air, so luxuriant lichen growth on trees indicates that the location is not polluted. Their presence says nothing about infestation or health of the trees.
Q15NEET 2013
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
Not quite — the answer is D.
Change in population = (natality + immigration) − (mortality + emigration) = (250 + 20) − (240 + 30) = 270 − 270 = 0. Taking only natality minus mortality gives the trap answer 10.
Q16AIPMT 2012 Mains
Cuscuta is an example of
Not quite — the answer is A.
Cuscuta (dodder) grows on the outer surface of its host plant and draws nutrients through haustoria, which makes it an ectoparasite. Brood parasitism is egg-laying in another bird's nest, as the cuckoo does.
Q17AIPMT 2011 Mains
The logistic population growth is expressed by the equation
Not quite — the answer is D.
Logistic (Verhulst-Pearl) growth is dN/dt = rN[(K − N)/K]: growth slows as N approaches the carrying capacity K. dN/dt = rN is exponential growth, and the other forms invert either the derivative or the term (N − K).
Q18AIPMT 2011 Mains
Consider the following statements (A)–(D) each with one or two blanks. (A) Bears go into ___(1)___ during winter to ___(2)___ cold weather (B) A conical age pyramid with a broad base represents ___(3)___ human population (C) A wasp pollinating a fig flower is an example of ___(4)___ (D) An area with high levels of species richness is known as ___(5)___ Which one of the following options gives the correct fill ups for the respective blank numbers from (1) to (5) in the statements?
Not quite — the answer is B.
Bears hibernate to escape the cold winter, a broad-based conical age pyramid indicates an expanding population, and an area with very high species richness is a hotspot. Fig and wasp is mutualism, not commensalism, and a broad base means growth, not stability, so only the choice with hibernation, escape, expanding and hot spot fills its blanks correctly.
Q19AIPMT 2011 Prelims
Which one of the following is categorised as a parasite in true sense?
Not quite — the answer is D.
The head louse lives on the host's scalp, lays its eggs on the hair and feeds on the host throughout its life, a true ectoparasite. The cuckoo is a brood parasite, the female Anopheles only visits to feed, and the foetus is not a separate parasitic organism.
Q20AIPMT 2010 Mains · Q19
Which one of the following is most appropriately defined?
Not quite — the answer is C.
A predator catches and kills its prey for food, which is the standard definition. One species benefiting while the other is unaffected is commensalism, not amensalism (one harmed, other unaffected). Parasites may be external (lice, ticks) and generally do not kill the host, and 'host' refers to the organism a parasite lives on, not any food provider.
Q21AIPMT 2010 Prelims · Q178
Study the four statements (a–d) given below and select the two correct ones out of them (a) A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers (b) Predator star fish Pisaster helps in maintaining species diversity of some invertebrates (c) Predators ultimately lead to the extinction of prey species (d) Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders The two correct statements are:
Not quite — the answer is A.
The lion and the sparrow both eat other organisms, so both are consumers. When the predatory starfish Pisaster was removed from rocky shores, more than 10 invertebrate species disappeared, which shows it maintains diversity. Predators usually keep prey numbers in check rather than wiping them out, and nicotine and strychnine are defensive chemicals, not metabolic disorders.
Q22AIPMT 2007 Prelims · Q121
Geometric representation of age structure is a characteristic of
Not quite — the answer is A.
Age pyramids show the proportion of pre-reproductive, reproductive and post-reproductive individuals, and age distribution is an attribute of a population. A community or ecosystem contains many species, so a single age structure cannot describe it.
Q23AIPMT 2007 Prelims · Q128
The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show?
Not quite — the answer is B.
A population that grows explosively and then crashes suddenly, without levelling off at a carrying capacity, follows a J-shaped (exponential) growth curve. A sigmoid curve would slow down and plateau instead of disappearing.
Q24AIPMT 2007 Prelims · Q166
A high density of elephant population in an area can result in
Not quite — the answer is A.
When many individuals of the same species crowd an area they compete for the same food, water and space, which is intraspecific competition. Interspecific competition involves different species, and elephants do not prey on each other.
Q25AIPMT 2006 Prelims · Q107
Praying mantis is a good example of :
Not quite — the answer is D.
The praying mantis is green or brown like the leaves and twigs it sits on, so it is hidden from both prey and predators; this is camouflage (cryptic colouration). It is a solitary insect, so 'social insects' is wrong, and it shows no warning colours.
Q26AIPMT 2006 Prelims · Q115
The formula for exponential population growth is :
Not quite — the answer is D.
In exponential growth the rate of change of population size with time is proportional to its size: dN/dt = rN, where r is the intrinsic rate of natural increase. The other options put the variables in the wrong positions.
Q27AIPMT 2006 Prelims · Q117
Niche overlap indicates :
Not quite — the answer is C.
A niche overlap means two species use one or more of the same resources (food, space, etc.), which can lead to competition. Two parasites on the same host is just one possible case and is not what the term means.
Q28AIPMT 2006 Prelims · Q149
Annual migration does not occur in the case of :
Not quite — the answer is C.
Salmon, Siberian crane and arctic tern all make long annual migrations. Salamanders are amphibians that stay in a small local area and do not make annual migrations.
Q29AIPMT 2005 Prelims · Q149
Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example :
Not quite — the answer is C.
Poison fangs are mainly used by snakes to kill prey (offence), not to escape predators. Puffing up (puffer fish), dark camouflage (melanic moths) and colour change (chameleon) all help avoid predation.
Q30AIPMT 2005 Prelims · Q172
Which one of the following pairs is mismatched ?
Not quite — the answer is B.
Prairies are temperate grasslands with few trees, so epiphytes (plants growing on other plants, typical of tropical rain forests) do not fit there. Acacia in savanna, permafrost in tundra and evergreen conifers in coniferous forest are all correct pairs.
How often Organisms and Populations came up
Questions from this chapter in each paper on this site.
- NEET 2021: 3
- NEET 2020: 1
- NEET 2018: 3
- NEET 2017: 2
- NEET 2017 (Gujarati paper): 1
- NEET 2016 Phase 2: 2
- NEET 2016 Phase 1: 1
- AIPMT 2014: 1
- NEET 2013: 1
- AIPMT 2012 Mains: 1
- AIPMT 2011 Mains: 2
- AIPMT 2011 Prelims: 1
- AIPMT 2010 Mains: 1
- AIPMT 2010 Prelims: 1
- AIPMT 2007 Prelims: 3
- AIPMT 2006 Prelims: 4
- AIPMT 2005 Prelims: 2
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