The Water and Nitrogen Cycles

Water in oceans, lakes, rivers, and other reservoirs changes from a liquid to a gas through _____________.

• Evaporation

• Transpiration

• Condensation

• Precipitation

Water also comes from plant leaves to the atmosphere through ________________.

• Evaporation

• Transpiration

• Condensation

• Precipitation

When the water cools down in the atmosphere, the water goes through _______________ and becomes clouds.

• Evaporation

• Transpiration

• Condensation

• Precipitation

The water doesn’t stay there! It comes back down to earth as _______________ through rain, sleet, or snow!

• Evaporation

• Transpiration

• Condensation

• Precipitation

What type of organism “fixes” the nitrogen for use by plants?

• Humans

• Plants

• Bacteria

• Aliens

Which nitrogen cycle process is occurring when bacteria convert ammonium to nitrite and then into nitrate?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Which of these nitrogen cycle processes converts atmospheric nitrogen to a soil form of nitrogen that is usable by plants?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Gas that makes up 78% of our atmosphere.

• Oxygen

• Nitrogen

• Hydrogen

• Carbon Dioxide

What process occurs when dead plant and animal matter decomposes and nitrogen is released back into the atmosphere?

• Assimilation

• Fixation

• Ammonification

• Denitrification

Plants and animals cannot use nitrogen directly from the air.

• True

• False