Understanding ecosystems is vital for aspiring medical students preparing for NEET, as it lays the foundation for appreciating the delicate balance of life. To help you prepare, we present 20+ multiple-choice questions related to ecosystems, each with an answer and detailed explanation.
1. Which of the following best defines an ecosystem?
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Explanation:
An ecosystem consists of all the living organisms (biotic components) in an area and the non-living elements (abiotic components) with which they interact.
2. In an ecosystem, which of the following is not a primary producer?
Answer:
Explanation:
Fungi are decomposers and not primary producers; they break down organic matter, whereas primary producers like algae, grass, and trees produce energy through photosynthesis.
3. Which trophic level would a carnivore that eats herbivores belong to?
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Explanation:
Carnivores that eat herbivores are secondary consumers and belong to the third trophic level in an ecosystem.
4. The main function of decomposers in an ecosystem is to:
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Explanation:
Decomposers break down dead organic matter, returning nutrients to the soil and ensuring the cycling of materials within the ecosystem.
5. What does an inverted pyramid of biomass represent in an ecosystem?
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Explanation:
An inverted pyramid of biomass represents ecosystems where the biomass of the higher trophic level is more than that of the lower trophic level, such as in aquatic ecosystems.
6. Approximately what percentage of energy is transferred from one trophic level to the next?
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Explanation:
Only about 10% of the energy from one trophic level is transferred to the next. The rest is lost as heat or used by the organism for metabolic processes.
7. Which of the following is an abiotic component of an ecosystem?
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Explanation:
Temperature is a non-living factor or condition that affects an ecosystem, making it an abiotic component.
8. What is the stable community that establishes itself after ecological succession called?
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Explanation:
The Climax Community is the final, stable community in ecological succession, which remains unchanged until disrupted by disturbances.
9. What does the ecological niche of an organism represent?
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Explanation:
The ecological niche of an organism refers to its role in the ecosystem, including how it gets its energy and nutrients, and its relationship with other organisms.
10. Which of the following ecosystems has the highest biodiversity?
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Explanation:
Tropical rainforests have the highest biodiversity among all ecosystems due to a combination of constant warmth and abundant rainfall.
11. The largest ecosystem in the world is?
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Explanation:
Oceans represent the largest ecosystem on Earth, covering about 71% of the planet's surface. They are incredibly diverse and home to a vast array of marine life, including various species of plants, animals, and microorganisms. Oceans play a crucial role in regulating the Earth's climate and weather patterns, and they significantly contribute to global biodiversity.
12. What are the two main components of an ecosystem?
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Explanation:
Ecosystems are made up of biotic (living organisms) and abiotic (non-living elements like temperature, water, sunlight) components, which interact and rely on each other.
13. Which of the following is the most stable ecosystem?
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Explanation:
Oceans are considered the most stable ecosystems due to their vast size, depth, and the ability to absorb and store heat. The sheer volume of the oceans allows them to buffer environmental variations and changes more effectively than smaller and more isolated ecosystems, such as mountains, deserts, or forests. The marine biodiversity and the complexity of oceanic ecosystems contribute to their resilience and stability over time.
14. Energy flow in an ecosystem is?
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Explanation:
In an ecosystem, the flow of energy is unidirectional. It moves from the sun to producers (plants) through photosynthesis, and then from producers to various levels of consumers (herbivores, carnivores, and decomposers) through feeding. Unlike nutrients, energy is not recycled within the ecosystem but is lost as heat at each trophic level, leading to a continual need for an input of new energy (solar radiation) to sustain life.
15. Which ecosystem has the highest primary productivity?
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Explanation:
Forests, due to their dense vegetation and diversity, exhibit the highest primary productivity among all ecosystems.
16. Which element is not cycled through the atmosphere in ecological flow?
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Explanation:
Phosphorus is not cycled through the atmosphere; it primarily cycles through the lithosphere, hydrosphere, and biosphere.
17. Which ecological pyramid is always upright?
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Explanation:
Pyramid of energy is always upright, depicting the diminishing availability of energy from the base to the top of the trophic levels.
18. Which factor does not influence the rate of decomposition?
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Explanation:
While temperature, moisture, and type of detritus significantly influence decomposition, light does not play a direct role.
19. What defines the character of a biological community?
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Explanation:
The character of a community is defined by its species richness, diversity, and the presence of dominant species.
20. Which community is observed during the final stage of ecological succession?
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Explanation:
The Climax Community is the final, stable community observed in ecological succession, characterized by a balanced and self-perpetuating system.