In India's coral reef ecosystems, what is the primary cause of coral bleaching observed in the Andaman and Nicobar Islands since 2020?
Answer: B
Elevated sea surface temperatures stress coral-zooxanthellae relationships, causing bleaching. This has been documented extensively in Andaman reefs.
Q.462Medium
Which statement about India's Project Tiger is most accurate?
Answer: B
India's tiger population has shown significant recovery, increasing from approximately 1400 tigers in 2006 to over 3700 by 2023 census.
Q.463Medium
In the bioaccumulation of DDT pesticide in aquatic food chains, which organism typically shows the highest concentration?
Answer: D
Biomagnification causes DDT concentration to increase at higher trophic levels, with apex predators (birds) showing highest concentrations.
Q.464Medium
Which of the following represents a density-dependent factor in the Indian subcontinent ecosystems?
Answer: B
Interspecific competition is density-dependent as its effect increases with population density. Environmental factors like rainfall are density-independent.
Q.465Medium
In India's mangrove ecosystems, which species serves as the keystone species maintaining ecosystem structure?
Answer: B
Rhizophora species form the structural foundation of mangrove ecosystems, providing nursery grounds and stabilizing sediment for other organisms.
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Q.466Medium
According to India's Climate Action Plan, what is the target reduction in carbon emissions intensity by 2030?
Answer: B
India has committed to reducing emissions intensity by 45% by 2030 from 2005 baseline levels as part of its NDC.
Q.467Hard
In a stable tropical forest ecosystem with high biodiversity, which Shannon diversity index range would be most appropriate?
Answer: C
High biodiversity ecosystems typically show Shannon index values between 2.5-4.0, reflecting greater species diversity and evenness.
Q.468Easy
Which of the following adaptations would be most beneficial for organisms in the Thar Desert ecosystem?
Answer: B
Desert organisms show adaptations like nocturnal behavior to avoid heat, and physiological mechanisms to conserve water.
Q.469Medium
In India's Eastern Ghats, the replacement of natural forest by monoculture plantations would result in:
Answer: C
Monoculture plantations reduce species and genetic diversity, making ecosystems more vulnerable to disturbances and less stable.
Q.470Hard
Which mechanism explains the coexistence of multiple predator species in the Indian savanna without competitive exclusion?
Answer: A
Niche partitioning allows different predator species to exploit different resources or hunting strategies, reducing direct competition.
Q.471Medium
According to the Convention on Biological Diversity (CBD) which India ratified, what is the current target for protecting land-based ecosystems?
Answer: B
The CBD's post-2020 global biodiversity framework targets 30% land protection by 2030, known as the '30 by 30' target.
Q.472Easy
In India's aquatic ecosystems, eutrophication is primarily caused by excessive amounts of which nutrients?
Answer: B
Nitrogen and phosphorus from agricultural runoff and sewage cause algal blooms and eutrophication in Indian water bodies.
Q.473Hard
In a predator-prey relationship within Indian grasslands, population cycles demonstrate Lotka-Volterra equations. If prey population peaks, the predator population would peak approximately:
Answer: C
Lotka-Volterra cycles show predator population lags behind prey by approximately 90 degrees, peaking after prey abundance increases.
Q.474Easy
Which of the following is the correct sequence of ecological succession in a freshwater pond ecosystem?
Answer: A
Ecological succession in freshwater ecosystems follows a predictable pattern starting with pioneer algae, progressing to submerged aquatic vegetation, then emergent plants, and finally leading to terrestrial vegetation as the habitat transitions.
Q.475Easy
The energy transfer efficiency from one trophic level to the next in an ecosystem is approximately:
Answer: B
The Lindeman 10% law states that only approximately 10% of energy is transferred from one trophic level to the next, with the remaining 90% lost as heat, respiration, and incomplete consumption.
Q.476Easy
Which of the following represents a biotic potential in population ecology?
Answer: A
Biotic potential refers to the inherent capacity of an organism to reproduce and increase in numbers when environmental conditions are optimal and resources are unlimited.
Q.477Easy
In the nitrogen cycle, which organism is responsible for nitrogen fixation in terrestrial ecosystems?
Answer: A
Azotobacter (free-living) and Rhizobium (symbiotic with legumes) are the primary nitrogen-fixing bacteria in soil that convert atmospheric N₂ into ammonia (NH₃), making nitrogen available to plants.
Q.478Easy
Which type of biome receives the least amount of annual rainfall globally?
Answer: B
Deserts are characterized by extremely low annual precipitation (less than 25 cm per year), making them the driest biomes on Earth, though tundras are also very dry.
Q.479Medium
The Western Ghats of India represent which type of biodiversity hotspot characteristic?
Answer: B
The Western Ghats qualify as a biodiversity hotspot due to their exceptional species richness, with over 50% endemic species and significant ongoing habitat destruction from human activities.
Q.480Medium
Which of the following is an example of competitive exclusion principle in natural ecosystems?
Answer: B
Gause's competitive exclusion principle states that two species with identical ecological niches cannot coexist indefinitely. Classic laboratory experiments with Paramecium species demonstrated that one species outcompetes and excludes the other.
