Nutrient Cycles

How much of the Earth's water is stored in the oceans?

• 50%
• 67%
• 97%
• 85%

Which of the following is NOT a stage of the nitrogen cycle?

• organisms breathe in nitrogen gas
• organisms release nitrogen compounds via waste or decomposition
• bacteria convert unusable nitrogen to usable nitrogen
• plants absorb nitrogen compounds from the soil

Which of the following is NOT part of the carbon cycle?

• condensation

• photosynthesis

• combustion (burning fossil fuels)

• respiration

When water vapor in the air cools and becomes liquid water.

• evaporation

• precipitation

• condensation

• transpiration

Plants get their nitrogen from

• the ground, through their roots

• the air, through holes in their leaves

• they make nitrogen using the Sun's energy

• bees pollinating them

Nitrogen fixation is done by _________.

• plants

• decomposers

• bacteria

• amoebas

When organisms use carbon dioxide to make glucose and release oxygen, the process is called ______.

• photosynthesis

• cellular respiration

• transpiration

• combustion

How do animals get the nitrogen they use for the molecules they need to live?

• breathing it in

• eating plants or other animals

• they make it from carbohydrates

• by breaking down water molecules

When plants do gas exchange, they open tiny holes in their leaves. While these are open, some water evaporates out of the plants. What is this called?

• condensation

• photosynthesis

• precipitation

• transpiration

After an organism dies, its carbon is put back into the soil and atmosphere through what process?

• decomposition

• evaporation

• respiration

• photosynthesis