The 10% law of energy transfer in an ecosystem states that only 10% of energy is transferred to the next trophic level. What happens to the remaining 90%?
Answer: B
The remaining 90% energy is lost through cellular respiration, heat dissipation, and decomposition processes at each trophic level, which is why ecosystems have fewer organisms at higher trophic levels.
Q.2Medium
The concept of 'ecological niche' refers to:
Answer: B
An ecological niche encompasses the organism's habitat, food, behavior, and role in the ecosystem - essentially its complete functional position in the environment.
Q.3Medium
Which of the following is a characteristic of r-selected species?
Answer: B
r-selected species (like rabbits and insects) have high reproductive rates, short generation times, and invest little in individual offspring care, prioritizing quantity over quality.
Q.4Medium
The carrying capacity of an environment is best defined as:
Answer: A
Carrying capacity (K) is the maximum population size that an environment can sustain indefinitely given available resources and environmental resistance.
Q.5Medium
In India's biodiversity hotspots, which region is NOT included in the recognized biodiversity hotspots?
Answer: D
India has 4 recognized biodiversity hotspots: Western Ghats, Indo-Burma, Himalayas, and Sundaland. Eastern plains are not recognized as a separate hotspot.
Advertisement
Q.6Medium
The concept of 'biomagnification' refers to:
Answer: B
Biomagnification is the process where toxic pollutants (like DDT, mercury) accumulate in higher concentrations in organisms at higher trophic levels due to bioaccumulation.
Q.7Medium
The process by which nitrogen is converted from atmospheric N₂ to usable forms by microorganisms is called:
Answer: B
Nitrogen fixation is the conversion of atmospheric N₂ to ammonia (NH₃) or nitrates by nitrogen-fixing bacteria like Rhizobium and Azospirillum.
Q.8Medium
Which of the following best describes 'eutrophication'?
Answer: B
Eutrophication is the over-enrichment of water with nutrients (phosphates and nitrates), leading to excessive algal growth, dead zones, and oxygen depletion.
Q.9Medium
Which of the following is a density-independent factor affecting population dynamics?
Answer: C
Drought is a density-independent (abiotic) factor because its effect on population is not influenced by population density. It equally affects all populations regardless of density.
Q.10Medium
A forest ecosystem in the Western Ghats shows a decline in apex predator population, leading to an increase in herbivore numbers and subsequent overgrazing. Which ecological principle is being violated in this scenario?
Answer: D
The carrying capacity of the ecosystem is being exceeded due to removal of natural predators. Herbivore populations exceed the ecosystem's ability to sustain them without degradation, violating the carrying capacity principle. This leads to overgrazing and ecosystem destabilization.
