Carbon cycle
Plants use CO2 in the process of __1____ to make __2___ and oxygen.
1. photosynthesis
2. Sugar
Plants release 430-470 billion tons of oxygen during process of ______.
photosynthesis
Phosphorus in not found in the free state in Nature, but is contained mostly in _______ and ________.
Rocks and minerals
Nitrogen gas makes up____% of our atmosphere.
78%
Animals use oxygen in the process of ______ and make more CO2.
Respiration
Atmosphere oxygen in the form of ____ provides protection from harmful ultraviolet rays.
ozone
It is an essential nutrient for life, as it makes up important chemicals such as _______.
DNA
Animals and plants cannot directly use all the nitrogen found in our _______.
Atmosphere
In the past, huge deposits of carbon were stored as dead plants and animals _______.
Decay
Oxygen is found everywhere on Earth, from Earth's ____ (rock) to the _____ where it is dissolved.
1. crust
2. Ocean
In the phosphorus cycle, phosphorus moves between the soil and ____, which are eaten by animals.
plants
Higher organisms use nitrogen to make their _____
Proteins
Equation of photosynthesis:
6CO2+6H2O--->C6H12O6 + 6O2
Oxygen is vital for _____ by animals, a process which produces CO2 and water.
Respiration
The animals use phosphorus, and then their _____ products help return the sulphur for the next generation of phosphorus in the soil.
waste
What is the systems of cycles called...
Ecosystems