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Question 1:

What is the primary source of energy in most ecosystems?

A) Sunlight
B) Soil nutrients
C) Water
D) Atmospheric gases

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Explanation: The correct answer is A) Sunlight. Sunlight is the primary source of energy in most ecosystems. It is captured by plants through the process of photosynthesis, which converts sunlight into chemical energy in the form of glucose. This energy then flows through the food web as organisms consume one another, transferring energy from one trophic level to the next.

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Question 2:

Which organisms are called primary producers in a food web?

A) Herbivores
B) Carnivores
C) Decomposers
D) Plants and algae

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Explanation: The correct answer is D) Plants and algae. Primary producers are organisms that can produce their own food through photosynthesis or chemosynthesis. In most ecosystems, plants and algae are the primary producers. They convert energy from sunlight into chemical energy, making it available to other organisms in the food web.

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Question 3:

Which trophic level typically has the highest biomass in a food web?

A) Primary consumers
B) Secondary consumers
C) Tertiary consumers
D) Primary producers

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Explanation: The correct answer is D) Primary producers. The trophic level that typically has the highest biomass in a food web is the primary producers. They convert a large amount of energy from the sun into biomass, and this biomass supports the rest of the food web. As energy flows through the food web, there is a decrease in biomass at each higher trophic level.

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Question 4:

Which organisms occupy the highest trophic level in a food web?

A) Primary producers
B) Herbivores
C) Carnivores
D) Decomposers

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Explanation: The correct answer is C) Carnivores. Carnivores, which are organisms that primarily consume other animals, occupy the highest trophic level in a food web. They are often referred to as tertiary or top consumers. Carnivores obtain energy by consuming herbivores or other carnivores, and they play an important role in regulating populations and energy flow within the ecosystem.

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Question 5:

What happens to energy as it moves through trophic levels in a food web?

A) Energy increases
B) Energy remains constant
C) Energy decreases
D) Energy is recycled

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Explanation: The correct answer is C) Energy decreases. As energy moves through trophic levels in a food web, there is a decrease in the amount of energy available at each higher level. This decrease occurs due to energy loss through metabolic processes, such as respiration, and inefficiencies in energy transfer between trophic levels. As a result, the energy available to organisms at higher trophic levels is significantly reduced compared to the energy available to primary producers.