Question 1

Which of the following best describes the role of decomposers in an ecosystem?

Accepted Answer

Decomposers like bacteria and fungi break down dead organisms and organic waste, recycling nutrients back into the ecosystem.

Question 2

In a food chain, which organism is typically at the top as the tertiary consumer?

Accepted Answer

A tertiary consumer is a carnivore that feeds on secondary consumers, occupying the top trophic level in the food chain.

Question 3

What percentage of energy is transferred from one trophic level to the next in an ecosystem?

Accepted Answer

The 10% law states that only approximately 10% of energy is transferred from one trophic level to the next, with the rest lost as heat.

Question 4

Which of the following is an example of a biotic component in an ecosystem?

Accepted Answer

Biotic components are all living organisms in an ecosystem, including plants, animals, and microorganisms.

Question 5

In a food chain, what percentage of energy is typically transferred from one trophic level to the next?

Accepted Answer

According to the 10% law of energy transfer, only about 10% of energy is passed to the next trophic level, with the rest lost as heat and metabolic processes.

Question 6

Which of the following is a biotic component of an ecosystem?

Accepted Answer

Biotic components include all living organisms such as plants, animals, and microorganisms, while abiotic components are non-living physical factors.

Question 7

Which of the following is an example of a decomposer in an ecosystem?

Accepted Answer

Decomposers like bacteria and fungi break down dead organic matter and return nutrients to the soil, completing the nutrient cycle.

Question 8

What is the primary source of energy for most ecosystems on Earth?

Accepted Answer

The Sun is the ultimate source of energy for nearly all ecosystems, as plants capture solar energy through photosynthesis.

Question 9

Which of the following activities would have the most negative impact on biodiversity in a forest ecosystem?

Accepted Answer

Deforestation through large-scale land clearing destroys habitats, removes species, and disrupts ecosystem balance more severely than other options.

Question 10

Which of the following is a biotic component of an ecosystem?

Accepted Answer

Biotic components include all living organisms such as producers, consumers, and decomposers, whereas abiotic components include non-living physical and chemical factors.

Question 11

A food chain consists of grass → grasshopper → frog → snake. If the grass contains 10,000 units of energy, how much energy will be available to the snake?

Accepted Answer

Energy transfer follows the 10% rule: grass (10,000) → grasshopper (1,000) → frog (100) → snake (10 units of energy).

Question 12

In an ecosystem, approximately what percentage of energy is transferred from one trophic level to the next?

Accepted Answer

The 10% law of energy transfer states that only about 10% of energy is passed to the next trophic level, while 90% is lost as heat and used in metabolic processes.

Agniveer Army GD Ecosystems & Environment

Ecosystems & Environment — Practice Questions