The ultimate source of energy for most ecosystems is:

Organisms that produce their own food using sunlight are called:

Which process converts light energy into chemical energy in glucose?

The process by which organisms release energy from glucose is called:

In a food chain, which organisms are always at the first trophic level?

What percentage of energy is typically transferred from one trophic level to the next?

The organisms that break down dead plants and animals into simpler compounds are called:

Which element is cycled through photosynthesis and respiration?

Which of the following organisms is a primary consumer?

Which term describes the feeding relationships in an ecosystem, showing many interconnected food chains?

What form of nitrogen can plants directly absorb from the soil?

Which process returns water to the atmosphere from plants?

Which biogeochemical cycle depends most on bacteria for movement of matter?

What role do detritivores (like earthworms) play in the biosphere?

Which of the following best describes an ecological pyramid of energy?

In the carbon cycle, which process releases carbon dioxide back into the atmosphere?

Organisms that rely on other organisms for food are called:

Which organisms are responsible for nitrogen fixation?

In an energy pyramid, which level contains the most available energy?

The cycling of matter in the biosphere ensures that: