In a pond ecosystem, phytoplankton occupy which trophic level?
Answer: B
Phytoplankton are autotrophic organisms that produce their own food through photosynthesis, making them primary producers in aquatic ecosystems.
Q.22Easy
The 10% law in ecology states that approximately what percentage of energy is transferred from one trophic level to the next?
Answer: C
The 10% law indicates that only about 10% of energy available at one trophic level is transferred to the next level, with the rest lost as heat and through metabolic processes.
Q.23Medium
Which of the following is an example of a density-dependent limiting factor?
Answer: B
Disease spread increases with population density, making it a density-dependent factor. Natural disasters are density-independent factors.
Q.24Medium
The process of ecological succession following a forest fire is classified as:
Answer: B
Secondary succession occurs on previously colonized areas where soil remains intact, such as after a fire. Primary succession occurs on bare rock or new land.
Q.25Easy
Which Indian biome is characterized by high temperature, low rainfall, and sparse vegetation?
Answer: C
The Thar Desert and other Indian desert regions exhibit high temperatures, minimal rainfall, and adapted vegetation like acacia and desert grasses.
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Q.26Medium
Mycorrhizal association between fungi and plant roots is an example of:
Answer: C
Both the fungus and plant benefit: fungi gain carbohydrates while helping the plant absorb water and minerals, making it a mutualistic relationship.
Q.27Medium
The phenomenon where predators and prey population cycles show a time lag is explained by:
Answer: B
Predator populations increase after prey abundance increases, creating characteristic cyclic patterns with a temporal delay between the two population peaks.
Q.28Medium
Which of the following contributes MOST to eutrophication of water bodies?
Answer: A
Nutrient overloading from agricultural runoff causes algal blooms and oxygen depletion, directly causing eutrophication.
Q.29Medium
The Western Ghats of India are recognized globally as a biodiversity hotspot primarily because:
Answer: B
The Western Ghats are designated as a hotspot due to exceptional plant and animal endemism, with thousands of species found nowhere else on Earth.
Q.30Easy
Which gas, released primarily from coal combustion and industrial processes, is a major contributor to acid rain?
Answer: B
Sulfur dioxide (SO₂) combines with water vapor to form sulfuric acid, which falls as acid rain, causing environmental damage.
Q.31Easy
In the nitrogen cycle, the conversion of atmospheric nitrogen to ammonia by bacteria is called:
Answer: B
Nitrogen fixation is the process where atmospheric N₂ is converted to ammonia by nitrogen-fixing bacteria, making it available to organisms.
Q.32Medium
The carrying capacity of an environment is determined by:
Answer: B
Carrying capacity is the maximum population size an environment can sustain indefinitely, determined by food, water, space, and other limiting factors.
Q.33Medium
Which of the following is the primary cause of habitat fragmentation in India's biodiversity hotspots?
Answer: B
Habitat fragmentation is predominantly caused by human activities like agricultural development, construction, and urban sprawl, dividing continuous ecosystems into isolated patches.
Q.34Medium
The concept of ecological niche differs from habitat in that niche refers to:
Answer: B
While habitat is 'where' an organism lives, niche describes 'how' it lives—its function, food preferences, behavioral patterns, and ecological role.
Rhizobium bacteria form symbiotic relationships with legume roots, fixing atmospheric nitrogen into ammonia and nitrates usable by plants.
Q.36Hard
The phenomenon of biomagnification poses serious health risks because:
Answer: B
Biomagnification causes toxic substances like DDT and heavy metals to accumulate in higher concentrations as they move up the food chain, affecting apex predators most severely.
Q.37Hard
Climate change in India is predicted to most severely impact which agricultural region?
Answer: B
Himalayan glaciers are melting at accelerated rates due to climate change, threatening water supplies for millions in northern India and affecting downstream agriculture.
Q.38Hard
The concept of 'tragedy of the commons' in environmental management refers to:
Answer: B
The tragedy of the commons occurs when individuals act in self-interest to exploit shared resources (like fisheries or forests), leading to overall depletion and collective loss.
Q.39Hard
Which regulatory mechanism would most effectively reduce plastic pollution in Indian coastal ecosystems?
Answer: B
While multiple factors contribute to ocean health, addressing single-use plastic directly tackles the primary source of marine plastic pollution through policy and behavioral change.
Q.40Medium
Which of the following organisms would show the highest concentration of pesticide residues in an aquatic food chain?
Answer: C
Bioaccumulation and biomagnification increase at higher trophic levels. Top predators accumulate the highest pesticide concentrations.
