Oxygen Cycle
What is the main source of oxygen on Earth?
Plants and algae, through photosynthesis.
Why is the carbon cycle important for life on Earth?
It helps balance carbon in the atmosphere, which keeps Earth’s temperature stable.
What is the main energy source for the carbon cycle?
The Sun’s energy, which helps plants perform photosynthesis.
What is nitrogen fixation?
The process where certain bacteria change nitrogen in the air into forms that plants can use, like ammonia or nitrates.
What are the two main forms of carbon on Earth?
Carbon dioxide (CO2) and organic carbon (found in living things).
What happens in the oxygen cycle?
Plants release oxygen during photosynthesis, animals breathe it in, and then animals release carbon dioxide, which plants use again.
How does the nitrogen cycle help plants grow?
The nitrogen cycle helps change nitrogen from the air into forms that plants can use for growth.
How does carbon get into the atmosphere?
Through things like breathing (respiration), burning fossil fuels, and the decay of dead plants and animals.
What happens during the nitrogen cycle?
Nitrogen is turned into usable forms by bacteria, plants take it up, animals eat plants, and when they die, decomposers return it to the soil.
Where is most of Earth’s carbon stored?
In the ocean, fossil fuels, and soil.
How does cutting down trees affect the oxygen cycle?
Fewer trees mean less oxygen is made, because trees produce oxygen through photosynthesis.
Why is the oxygen cycle important for life on Earth?
It ensures we always have enough oxygen for breathing and cellular processes.
What role do plants play in the carbon cycle?
Plants take in carbon dioxide during photosynthesis and convert it into food and oxygen.
What do denitrifying bacteria do in the nitrogen cycle?
They convert nitrates back into nitrogen gas, which goes back into the atmosphere.
What is the Haber-Bosch process, and how does it affect the nitrogen cycle?
The Haber-Bosch process is a way to make fertilizer. It adds extra nitrogen to the soil, which can throw off the natural nitrogen cycle.
What two living things are in the oxygen cycle?
Plants and Animals
How does the carbon cycle help control Earth's climate?
It helps keep the right amount of carbon dioxide in the atmosphere, which affects how much heat the Earth gets.
How does burning fossil fuels affect the carbon cycle?
It releases extra carbon dioxide into the atmosphere, which can cause global warming.
How do fertilizers affect the nitrogen cycle?
Fertilizers add too much nitrogen to the soil, which can cause pollution and harm plants and animals.
How does the Sun affect the carbon cycle?
The Sun's energy powers photosynthesis in plants, which helps absorb carbon dioxide from the atmosphere.
Why is the oxygen cycle important for life on Earth?
It provides the oxygen that animals, including humans, need to breathe and live.
How does the nitrogen cycle help all living things on Earth?
It provides nitrogen, which is necessary for proteins and DNA in plants and animals.
How does carbon move between plants, animals, and the atmosphere?
Carbon moves through photosynthesis, respiration, and decomposition.
What objects does nitrogen move through?
the atmosphere, soil, plants, and bacteria.
How do microorganisms help in the nitrogen cycle?
They fix nitrogen from the air, break down dead organisms to release nitrogen back into the soil, and help plants use nitrogen.