Food Webs and Ecological Pyramids Quiz

Food Web

A complex network of interconnected food chains showing how energy flows through an ecosystem.

Example: A pond ecosystem food web includes algae, small fish, frogs, birds, and decomposers

Trophic Level

Each step in a food chain or food web

Example: Plants are primary producers (first trophic level), while wolves are top predators (highest trophic level).

Food Chain

A series of steps in which organisms transfer energy by eating and being eaten

Example: Grass → Rabbit → Fox.

food chain vs food web

A food chain is a simple, linear sequence showing how energy moves from one organism to another.

Example: Grass → Rabbit → Fox

A food web is more complex, showing multiple interconnected food chains within an ecosystem. It better represents the real relationships between organisms.

Ecological Pyramid

Diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web

Producers

Organisms that make their own food

Primary Consumers (Herbivores)

Eat only producers (plants and algae).

Examples: Deer, rabbits, caterpillars, and grasshoppers.

Secondary Consumers (Carnivores or Omnivores)

Eat primary consumers.

Examples: Frogs, snakes, and birds like hawks.

Tertiary Consumers (Top Predators or Large Carnivores)

Eat secondary consumers.

Examples: Sharks, eagles, and wolves.

Quaternary Consumers (Apex Predators)

Have no natural predators and sit at the top of the food chain.

Examples: Lions, killer whales, and polar bears.

What happens to energy as you move up the food chain?

Energy decreases as it moves up the food chain, making higher-level consumers fewer in number.

What is the 10% energy rule?

When energy moves up the food chain from one trophic level to the next, only about 10% of the energy is transferred, while the remaining 90% is lost as heat or used for metabolism.

Carnivores

A consumer that eats only animals.

Example: Lions, sharks, and hawks are all carnivores.

Herbivores

Consumers that eat only plants

Example: Deer, cows, and caterpillars are herbivores.

Omnivores

Consumers that eat both plants and animals.

Example: Bears, raccoons, and humans are omnivores.

Autotroph

An organism that makes its own food using sunlight or chemicals.

Example: Plants and algae use photosynthesis to create energy.

Heterotroph

An organism that obtains energy from the foods it consumes; also called a consumer

Example: Herbivores, carnivores, and decomposers are all heterotrophs.

Scavengers

An organism that eats dead or decaying animals but does not hunt.

Example: Vultures, hyenas, and crabs are scavengers.

Decomposers

Organisms that break down dead matter and recycle nutrients.

Example: Fungi and bacteria decompose organic material, returning nutrients to the soil.