Matter and Energy in the Ecosystem

Which statement describes the role of decomposers in a food web?

• Decomposers are not necessary in a food web.

• Decomposers break down matter so plants can use it.

• Decomposers create energy by producing their own food.

• Decomposers store matter and energy until it is needed in an ecosystem.

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NGSS.MS-LS2-3

Producers and consumers are both pictured in a diagram of a food web. Which statement best describes how they differ from one another?

• Consumers produce all the energy they need.

• Consumers eat only animals, and producers eat only plants.

• Producers eat living organisms, and consumers eat organisms that have died.

• Consumers obtain energy by eating food, and producers obtain energy from sunlight.

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NGSS.MS-LS2-3

What is the primary role of decomposers in a food web?

• to control the population of producers and consumers

• to compete with producers for energy and other resources

• to provide a source of energy for the producers in the ecosystem

• to recycle energy and materials from dead producers and consumers

Tags

NGSS.MS-LS2-3

A student is identifying food chains in a diagram of a food web. Which of these organisms might be a consumer?

• a frog

• a water lily

• a redwood tree

• athlete's foot fungus

Tags

NGSS.MS-LS2-3

Matter that make up the living and dead organisms of an ecosystem.

• Abiotic

• Biotic

• Consumer

• Energy storage molecules

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NGSS.MS-LS2-3

Energy flow in ecosystems is best described as:

• A cyclical loop where energy is recycled.

• A linear flow from the sun to producers and then to various levels of consumers.

• A web where energy flows equally in all directions.

• A closed system where energy is not lost.

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NGSS.MS-LS1-6

NGSS.MS-LS2-3

The amount of matter in an ecosystem is always ​ (a)   . It just changes forms and is recycled.

• constant

• decreasing

• increasing

Tags

NGSS.MS-LS2-3

Match the following

• anything that has mass and takes up space.

• energy pyramid

• a tool that can be used to trace the flow of energy through an ecosystem.

• law of conservation of mass

• the ability to do work and enables organisms to use matter in life processes.

• law of conservation of energy

• energy cannot be created or destroyed

• matter

• mass cannot be created or destroyed

• energy

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NGSS.MS-LS1-6

NGSS.MS-LS2-3

NGSS.MS-PS1-5

NGSS.MS-PS3-5

A mangrove swamp contains many organisms living among the large roots of the mangrove trees. The food web shows some of the relationships in that ecosystem. According to the food web, which of these organisms is a producer in the mangrove swamp?

• mold

• prawn

• pelican

• phytoplankton

Tags

NGSS.MS-LS2-3

Ants eat a variety of foods, including plants and other insects. A reptile called a thorny devil eats ants. If a food chain that includes the thorny devil and ants is represented by an energy pyramid, the ants would occupy the ___________ pyramid level.

• top

• middle

• bottom

Answer explanation

Only producers can occupy the bottom level of an energy pyramid. Since ants are prey for thorny devils, they cannot occupy the top level of the pyramid.

Tags

NGSS.MS-LS2-3