Matter Cycles

What term is given by scientists to the living parts of an ecosystem?

• Biotic Factors
• Abiotic Factors
• Community
• Population

How does carbon dioxide leave the atmosphere?

• Through transpiration
• Through photosynthesis
• Through factory emission
• Sunlight

What is one way that carbon enters the atmosphere?

• Sunlight
• Factory emissions
• Ocean uptake
• Rain

When carbon combines with oxygen, what forms?

• Nitrogen
• Argon
• Carbon dioxide
• Sodium hydrogen

Because of Earth's cycles, organisms can use what over and over?

• energy
• matter
• plants
• food

Where do animals get nitrogen from?

• soil
• air
• water
• plants

How do animals obtain carbon?

• decomposing
• combustion
• eating plants 
• breathing it in

Matter on Earth is limited, so it must be used ____________________________.

• only once
• over and over again
• by only animals
• at night only

What is the original source of almost all energy in most ecosystems?

• carbohydrates
• sunlight
• water
• carbon

What role do these organisms play in their ecosystem as they break down matter?

• producer
• primary consumer
• secondary consumer
• decomposer