The Natural Cycles

Name the sphere.

• geosphere
• biosphere
• hydrosphere
• atmosphere

Name the sphere.

• atmosphere
• hydrosphere
• biosphere
• geosphere

Name the sphere.

• atmosphere
• geosphere
• hydrosphere
• biosphere

Evaporation is 

• water vapor turning to water
• water falling from the skies
• water turning into vapor
• process of releasing energy from food

Which describes a part of the nitrogen cycle?

• plants use nitrogen gas and return it to the soil
• lightning turns fixed nitrogen into nitrogen gas
• bacteria in the soil fix nitrogen for plants
• animals turn fixed nitrogen into nitrogen gas

Petroleum is made from

• coal and oil
• bacteria and fungi
• plants releasing oxygen
• decayed organisms

Burning fuels in cars and factories

• puts oxygen into the air
• puts nitrogen into the air
• upsets the balance of the nitrogen cycle
• upsets the balance of the carbon-oxygen cycle

Water falls to Earth as rain after water vapor ____________ into clouds.

• condenses
• becomes heavy
• evaporates
• warms

Plants return water to the environment through - 

• respiration
• transpiration
• photosynthesis
• evaporation

Ammonia is a usable form of  ______________ that bacteria use in the _____________________.

• protein; nitrogen cycle
• water vapor; water cycle
• nitrogen; nitrogen cycle
• carbon dioxide; carbon oxygen cycle