Ecosystems - Energy, Producers, and Consumers

Flashcards cover producers, autotrophs vs heterotrophs, energy sources, food chains and webs, trophic levels, energy pyramids, and thermodynamics as they relate to ecosystems.

What term describes organisms that make their own energy-rich food using light or chemical energy?

Autotrophs (primary producers)

What term describes organisms that obtain energy by eating other organisms?

Heterotrophs

What are primary producers?

Autotrophs that obtain energy from the sun or chemicals and convert it to a usable form (e.g., plants, algae, some bacteria)

What energy sources do producers use?

Light energy (photosynthesis) and chemical energy (chemosynthesis)

What is photosynthesis?

The process by which producers convert CO2 and water into carbohydrates using light energy, releasing oxygen.

What is chemosynthesis?

The process by which producers use chemical energy, often from hydrogen sulfide, to synthesize carbohydrates, producing sulfur compounds.

Why are producers essential in ecosystems?

All ecosystems depend on producers because they provide the base of the energy available to all other organisms.

Who are typical consumers?

Animals, fungi, some bacteria, and some protists that obtain energy by eating other living or once-living organisms.

What are the three main types of consumers?

Herbivores, omnivores, and carnivores.

What is a herbivore?

An organism that obtains energy from eating plants.

What is an omnivore?

An organism that obtains energy from eating plants and animals.

What is a carnivore?

An organism that obtains energy from eating animals.

What is a decomposer?

An organism that obtains energy by chemically breaking down organic matter at the molecular level.

What is a detritivore?

An organism that obtains energy by grinding organic matter into smaller pieces.

What is a scavenger?

An organism with specialized digestion allowing consumption of carcasses and rotten flesh.

Why are decomposers important?

They return vital nutrients back into the environment.

What is a food chain?

A linear sequence linking species by feeding relationships; energy moves in one direction, with heat energy lost at each step.

In the food chain grass → grasshopper → shrew → owl, what trophic level is grass?

Grass is a producer (base trophic level).

What is a food web?

A network of all the feeding relationships in an ecosystem, linking many food chains.

What are trophic levels?

The levels of nourishment in a food chain (producer, primary consumer, secondary consumer, tertiary consumer, etc.).

What are the four main trophic levels from base to top?

Producer (base), Primary consumer, Secondary consumer, Tertiary consumer (top).

What is the first trophic level?

Producer (base).

What is the second trophic level?

Primary consumer (herbivore).

What is the third trophic level?

Secondary consumer (omnivore or carnivore).

What is the fourth trophic level?

Tertiary consumer (omnivore or mostly carnivore).

How does energy flow in ecosystems?

In one direction from producers to higher trophic levels; heat energy is released at each transfer.

What is the 10% rule?

Only about 10% of the energy at one trophic level is transferred to the next level; the rest is lost as heat, used by organisms, or waste.

Why can a food chain typically include only up to five organisms?

Because of energy loss at each transfer, limiting the number of trophic levels that can be supported.

What is a biomass pyramid?

A pyramid showing the mass of producers, primary consumers, and higher levels needed to support the next level.

What is a pyramid of numbers?

A pyramid showing the numbers of individual organisms at each trophic level.