I Learn Review Biology

Front

What is an autotroph?

Back

An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. Examples include plants and some bacteria.

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What is a heterotroph?

Back

A heterotroph is an organism that cannot produce its own food and instead obtains it by consuming other living or once-living things. Examples include animals, fungi, and many bacteria.

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What is the difference between density-dependent and density-independent factors?

Back

Density-dependent factors are influenced by the population size (e.g., competition, predation), while density-independent factors affect populations regardless of their size (e.g., natural disasters, climate).

Front

What role do producers play in a food chain?

Back

Producers are the first step in a food chain; they create energy through photosynthesis and provide food for consumers.

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Why are food chains typically limited to three to five trophic levels?

Back

Food chains are limited to three to five trophic levels due to insufficient energy to support more levels, as energy decreases at each trophic level.

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What is photosynthesis?

Back

Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

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What is a food web?

Back

A food web is a complex network of feeding relationships among various organisms in an ecosystem, showing how energy and nutrients flow.

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What is a trophic level?

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A trophic level is a position in a food chain or food web, defined by how an organism obtains its energy.

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What is the significance of decomposers in an ecosystem?

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Decomposers break down dead organic matter, recycling nutrients back into the ecosystem and supporting plant growth.

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What is competition in ecology?

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Competition occurs when two or more organisms vie for the same resources (e.g., food, space) in an ecosystem.