The Water Cycle

HOME

Precipitation

• Water that has condensed in the air forms clouds

• Drops fall to Earth and accumulate in oceans and lakes

Back to the

Water Cycle

Using WaterEvaporation

Using Water

• Plants and animals need water to live

• Water is pulled from bodies of water or from the ground (groundwater)

Back to the

Water Cycle

WastePrecipitation

Waste

• Plants and animals return water to environment through transpiration

• Animals return water to ground and bodies of water through urine

Evaporation

Back to the

Water Cycle

Using Water

Evaporation

• Water from oceans, lakes, and other bodies of water re-enters the atmosphere through evaporation

Back to the

Water Cycle

PrecipitationWaste

The Carbon Cycle

HOME

Photosynthesis

• Plants use CO2 from the atmosphere to make high-energy carbon molecules

Back to the

Carbon Cycle

Metabolism

Respiration

Gas Exchange

Pollution

Metabolism

• Organisms use high energy carbon molecules for growth

Back to the

Carbon Cycle

Respiration

Waste

Decomposition

Photosynthesis

Respiration

• CO2 is released through aerobic respiration (breathing, for example)

Back to the

Carbon Cycle

PhotosynthesisMetabolism

Decomposition

Waste

• Carbonates released into ground and water supply

Back to the

Carbon Cycle

Gas Exchange

Metabolism

Photosynthesis

Decomposition

Gas Exchange

• CO2 is exchanged between the air and water

Back to the

Carbon Cycle

PhotosynthesisWaste

Decomposition

• When organisms die and decay, the carbon molecules in them enter the soil.

• Microorganisms break down the molecules, releasing CO2

Back to the

Carbon Cycle

Photosynthesis

PollutionMetabolism

Pollution

• Remains of dead organisms are converted into fossil fuels (over millions of years!)

• Combustion of fossil fuels and wood releases CO2

Back to the

Carbon Cycle

Using WaterMetabolism

The Nitrogen Cycle

HOME

Nitrogen Fixation

• Lightning and bacteria convert atmospheric nitrogen into nitrates (NO3) and ammonia (NH3)

Back to the

Nitrogen Cycle

Protein Production

Return to Atmosphere

Protein Production

• Plants use nitrogen molecules to make amino acids

Back to the

Nitrogen Cycle

Nitrogen FixationConversion

Conversion

• Consumers convert plant proteins to animal proteins

Back to the

Nitrogen Cycle

WasteProtein Production

Waste

• Decomposers break down animal and plant matter into nitrogen compounds

Back to the

Nitrogen Cycle

Return to Atmosphere

PollutionConversion

Return to Atmosphere

• Nitrogen compounds break down into gas and return to air

Back to the

Nitrogen Cycle

Nitrogen FixationWaste

Runoff

• Runoff of nitrates in fertilizers enters groundwater and soil

Back to the

Nitrogen Cycle

Protein Production

Pollution

• Nitrous Oxide from burning fossil fuels falls as Nitric Acid in rainwater

Back to the

Nitrogen Cycle

Waste

Question 1: What would happen to primary producers and consumers if nitrogen-fixing bacteria were removed from the ecosystem?

Question 2: Grandma Johnson had very sentimental feelings toward Johnson Canyon, Utah, where she and her late husband had honeymooned long ago. Her feelings toward this spot were such that upon her death she requested to be buried under a creosote bush overlooking the canyon.

Trace the path of a CARBON atom from Grandma Johnson’s remains to where it could become part of a hawk.

Note: A hawk is a carnivore, but it did NOT dig up and consume Grandma Johnson’s remains!!!