30 MCQs on Habitat & Niche (CSIR NET Part C type)

Habitat, Niche, Fundamental vs Realized Niche, Competition, Coexistence, Hutchinson’s concept आदि से ही 30 MCQs (CSIR NET Part C type, Medium–High standard

Concept & Memory based (सीधे definition/terms/हिस्ट्री)

Multiple Statement based (कौन सा सही है/गलत है)

Research/Experiment based (जैसे CSIR Part C में आता है — common garden, niche overlap, competition outcomes)

🟢 30 MCQs on Habitat & Niche (CSIR NET Part C type)

Q1.

Which of the following correctly distinguishes habitat from niche?

A. Habitat is functional role; niche is physical place

B. Habitat includes abiotic + biotic parameters; niche includes tolerances + requirements

C. Habitat is always smaller than niche

D. Niche is a physical area while habitat is functional

Q2.

Hutchinson’s (1957) concept of “n-dimensional hypervolume” for niche refers to:

A. Species’ geographic range only

B. Environmental tolerance + resource use along multiple axes

C. Only biotic interactions

D. Only abiotic factors like temperature and salinity

Q3.

Which of the following organisms best illustrates the difference between habitat and niche?

A. Lion in savanna grassland

B. Zooplankton in a pond

C. Nitrogen-fixing Rhizobium in legume root nodules

D. Epiphytic orchids on tree barks

Q4.

Statement I: Fundamental niche is always larger than realized niche.

Statement II: Realized niche can occasionally be larger than fundamental niche in cases of facilitation.

Choose the correct answer:

A. Only I true

B. Only II true

C. Both I and II true

D. Both false

Q5.

The realized niche of a species is restricted compared to its fundamental niche primarily due to:

A. Mutations

B. Interspecific interactions (competition, predation, parasitism)

C. Abiotic tolerance limits

D. Genetic drift

Q6.

In an experimental setup, two paramecium species (P. aurelia & P. caudatum) are grown together. P. aurelia outcompetes P. caudatum, reducing its density drastically. This illustrates:

A. Competitive exclusion principle

B. Coexistence by niche partitioning

C. Neutralism

D. Amensalism

Q7.

Which ecological concept is best described by “warblers partitioning a tree into feeding zones”?

A. Character displacement

B. Resource partitioning

C. Fundamental niche expansion

D. Competitive release

Q8.

In the absence of predators, a herbivore species spreads into a wider range of habitats. This is an example of:

A. Realized niche expansion

B. Fundamental niche expansion

C. Competitive exclusion

D. Niche conservatism

Q9.

Consider a graph where two species have overlapping resource-use curves. The degree of overlap represents:

A. Habitat differentiation

B. Niche overlap and potential competition

C. Fundamental niche expansion

D. Carrying capacity

Q10.

Statement I: Hutchinson’s niche is an n-dimensional hypervolume.

Statement II: Each dimension represents an environmental condition or resource.

A. Only I correct

B. Only II correct

C. Both correct

D. Both incorrect

Q11.

Which pair is correctly matched?

A. Gause – Competitive exclusion principle

B. Grinnell – Fundamental vs realized niche

C. Elton – Habitat concept

D. Hutchinson – Habitat heterogeneity

Q12.

An invasive species colonizes a habitat and reduces the native species’ realized niche. Which mechanism explains this?

A. Competitive exclusion

B. Predation release

C. Abiotic filtering

D. Neutral drift

Q13.

Which of the following is NOT a correct example of niche differentiation?

A. Nocturnal vs diurnal feeding

B. Roots at different soil depths

C. Birds feeding on insects vs seeds

D. Two species occupying same resources at same time without interference

Q14.

Which factor does NOT determine habitat but is key to defining niche?

A. Temperature

B. Rainfall

C. Trophic role in food web

D. Geographic location

Q15.

If a weak competitor species survives only in predator-free patches, this represents:

A. Realized niche

B. Fundamental niche

C. Competitive release

D. Ecological compression

Q16.

“Neutral theory of biodiversity” by Hubbell emphasizes:

A. Niche differentiation

B. Role of ecological equivalence among species

C. Only abiotic filtering

D. Predator–prey oscillations

Q17.

Experimental scenario: Two grass species grow equally well alone in wet soil. When grown together, one species dominates in wet soil, while the other persists in dry margins. This illustrates:

A. Niche partitioning

B. Niche conservatism

C. Neutralism

D. Fundamental niche expansion

Q18.

Which is a direct consequence of niche overlap?

A. Mutational load

B. Increased interspecific competition

C. Population bottleneck

D. Genetic drift

Q19.

Species that survive in a very narrow temperature and pH range are called:

A. Generalists

B. Specialists

C. Opportunists

D. Keystone

Q20.

If interspecific competition reduces a species’ realized niche width, this process is termed:

A. Niche compression

B. Niche broadening

C. Ecological release

D. Neutral drift

Q21.

Which ecological interaction can sometimes enlarge realized niche beyond fundamental niche?

A. Parasitism

B. Mutualism/facilitation

C. Predation

D. Competition

Q22.

If two species coexist stably, the most likely mechanism is:

A. Resource partitioning

B. Complete niche overlap

C. Predator–prey oscillation

D. Neutral drift

Q23.

According to Hutchinson, niche breadth is:

A. Always fixed for a species

B. Measured as variance in resource use along each niche axis

C. Determined only by habitat size

D. A function of geographic dispersal

Q24.

Which ecological principle best explains why two closely related species of finches evolve different beak sizes when coexisting?

A. Niche conservatism

B. Character displacement

C. Competitive exclusion

D. Neutral theory

Q25.

Fundamental niche of a desert cactus includes tolerance to drought and high temperature. Its realized niche excludes some patches where:

A. Soil nutrients are higher

B. Other competitive shrubs dominate

C. Rainfall is lower

D. Pollinators are abundant

Q26.

Which graph represents niche differentiation under competition?

A. Two overlapping Gaussian curves that shift apart

B. Two identical curves completely overlapping

C. Flat line of resource use

D. Single bell curve with no overlap

Q27.

“Ecological release” is best illustrated when:

A. A species expands niche in absence of competitors

B. Predators suppress prey population

C. Two species show identical realized niches

D. Competition reduces niche breadth

Q28.

Hutchinson’s niche theory differs from Elton’s because:

A. Hutchinson emphasized role and function

B. Elton emphasized multi-dimensional tolerances

C. Hutchinson emphasized n-dimensional hypervolume

D. Elton emphasized only realized niche

Q29.

Which species concept is most directly linked with the ecological niche?

A. Morphological species concept

B. Biological species concept

C. Ecological species concept

D. Evolutionary species concept

Q30.

In an experiment, species A and B feed on overlapping seed sizes. Over generations, species A shifts to smaller seeds while species B shifts to larger seeds. This outcome is best explained by:

A. Neutralism

B. Character displacement via competition

C. Competitive exclusion

D. Predator-mediated coexistence

🟡 Answer Key (for self-check after practice):

1-B, 2-B, 3-C, 4-C, 5-B, 6-A, 7-B, 8-A, 9-B, 10-C,

11-A, 12-A, 13-D, 14-C, 15-A, 16-B, 17-A, 18-B, 19-B, 20-A,

21-B, 22-A, 23-B, 24-B, 25-B, 26-A, 27-A, 28-C, 29-C, 30-B

👉 अब आपके पास 30 fresh Part C type practice questions हैं जो niche/habitat/fundamental-realized niche/competition से जुड़े हैं।