Energy Basics
Producers and Consumers
Energy Flow in Ecosystems
Cycles of Matter
Cycles of Matter 2
100

What is the primary source of energy for most ecosystems on Earth?

The Sun

100

What type of organism is at the base of every food chain?

Producers

100

What is the term for each step in a food chain or food web?

Trophic level

100

What process in the water cycle involves water vapor cooling and changing into liquid droplets?

Condensation

100

In the nitrogen cycle, what process converts ammonia in the soil into nitrate ions that plants can absorb?

Nitrification

200

What term describes organisms that can make their own food from sunlight or chemicals?

Autotrophs

200

Which type of consumer only eats plants?

Herbivore

200

About what percentage of energy is transferred from one trophic level to the next?

Approximately 10%

200

Name one process in the carbon cycle that releases carbon dioxide into the atmosphere.

Respiration or combustion

200

Which cycle does not include an atmospheric component?

Phosphorus cycle

300

In what form is energy stored in plants?

Chemical energy in the form of glucose

300

What do you call an organism that breaks down dead matter?

Decomposer

300

What type of diagram shows the flow of energy between organisms in an ecosystem?

An energy pyramid

300

Which cycle involves nitrogen-fixing bacteria converting nitrogen gas into forms usable by plants?

Nitrogen cycle

300

What process in the nitrogen cycle converts nitrate back into nitrogen gas?

Denitrification

400

ame the process by which green plants convert sunlight into energy.

Photosynthesis

400

Name an example of a primary consumer in a grassland ecosystem.

A rabbit, zebra, wildebeest, insects.

400

What kind of organism is both a secondary and tertiary consumer?

Omnivore (depending on its diet)

400

In the phosphorus cycle, what natural process releases phosphorus into the soil?

Weathering of rocks

400

What form of nitrogen is most easily absorbed by plants?

Nitrate (NO₃⁻)

500

What is the law that states energy cannot be created or destroyed, only transformed?

The Law of Conservation of Energy

500

What is an apex predator?

An animal at the top of the food chain with no natural predators

500

What is the difference between a food chain and a food web?

A food chain shows a single path of energy flow, while a food web shows multiple interconnected food chains.

500

What is the main role of decomposers in the nutrient cycles?

They break down dead matter, returning nutrients to the soil.

500

How does burning fossil fuels contribute to global warming in terms of the carbon cycle?

It releases excess carbon dioxide (CO₂) into the atmosphere, trapping heat and enhancing the greenhouse effect.