Earth Cycles

Earth's Cycles

How do they affect our world?

Water Cycle

• The water cycle has several steps.

• Each step moves water in a circular motion.

• There's is not definitive start or end to the Water Cycle.

Water Cycle

• Water evaporates from bodies of water like lakes or streams. It can also transpire from plant's leaves.

• Water cools and condenses into clouds in the atmosphere.

• When the clouds become too heavy, water exits as precipitation.

• Water that falls, runs off into lakes, streams, rivers, and oceans.

• Some water even becomes trapped under the Earth's surface as groundwater.

Multiple Choice

Which of the following actions would NOT count as part of the Water Cycle?

• Rain running off into a river.

• Water in your glass that you drink.

• Clouds forming over a mountain

• Puddles evaportating after a storm.

Multiple Select

Which of these IS a step in the water cycle.

• evaporation

• condensation

• transpiration

• precipitation

• salination

Nitrogen Cycle

• In order to survive, plants on earth need Nitrogen, which they can get mostly from soil.

• Nitrogen is in the air around us, but must be changed or fixed before it can be used by plants.

Nitrogen Cycle

• Nitrogen is taken in by plants through the roots.

• When animals eat the plants, they absorb some nitrogen, but the rest is expelled through body functions like peeing.

• Nitrogen can be fixed, or changed, by lighting or volcanos, as well.

• When animals die they are broken down by decomposers and bacteria.

• Bacteria change the nitrogen into a form useful to plants.

• Farmers may also add Nitrogen to the soil for crops.

Multiple Select

Which of these are sources of Nitrogen?

• animal waste

• bacteria

• fertilizer

• plants

• lightning

Oxygen-Carbon Cycle

• All parts of the biosphere participate in the Oxygen-Carbon cycle.

• All living things require either Carbon Dioxide or Oxygen to exist .

Nitrogen Cycle

• Plants change sunlight, Carbon Dioxide, and water into Oxygen and sugar.

• Plants release the Oxygen into the air.

• Animals take in the oxygen through respiration.

• This includes marine animals like fish ( through gills ).

• Bacteria and fungi can break down dead and organisms and release Carbon Dioxide back into the atmosphere.

• Man-made sources, such as burning fossil fuels like coal, also contribute to the Carbon Dioxide.

Multiple Choice

Do bacteria and fungi partake in the Oxygen Carbon cycle?

• Yes

• No