Carbon Cycle
What is carbon?
Carbon is an element found in all living things.
What is a carbon sink?
A carbon sink stores carbon and helps reduce CO2 in the atmosphere.
How does burning fossil fuels affect carbon dioxide levels in the atmosphere?
It adds large amounts of carbon dioxide, increasing greenhouse gases.
Why do plants and animals need nitrogen?
Nitrogen is essential for making proteins and DNA, which are vital for life.
How do fertilizers help plants grow?
Fertilizers add nitrogen to soil, which plants need to grow.
How do plants get carbon from the air, and what do they do with it?
Plants take in carbon dioxide and use it to make food through photosynthesis.
What happens to carbon when plants and animals die?
Decomposes break down dead organisms, releasing carbon into the soil or air.
Why does cutting down trees increase carbon dioxide in the air?
Fewer trees mean less CO2 is absorbed from the atmosphere.
What is nitrogen fixation?
Nitrogen fixation is converting nitrogen gas into forms plants can use.
What is eutrophication?
Eutrophication is excessive algae growth caused by too many nutrients.
How do animals get carbon, and how do they release it back into the air?
Animals get carbon by eating and release it as carbon dioxide when they breathe.
What is the difference between the fast carbon cycle and the slow carbon cycle?
The fast cycle moves carbon quickly through living things; the slow cycle stores carbon in rocks and fossil fuels for millions of years.
What happens to ocean water when it absorbs extra carbon dioxide from the air?
The water becomes acidic, which harms marine organisms.
What is ammonification?
Ammonification is bacteria turning nitrogen from dead matter into ammonia.
How can burning fossil fuels harm the nitrogen cycle?
It releases nitrogen oxides that cause acid rain and pollute air and water.
How do photosynthesis and cellular respiration work together in the carbon cycle?
Photosynthesis makes food and oxygen using carbon dioxide; cellular respiration breaks down food and releases carbon dioxide
How do volcanoes affect the amount of carbon dioxide in the atmosphere?
Volcanoes release carbon dioxide stored inside Earth during eruptions.
How does ocean acidification affect coral reefs and animals that live there?
It weakens coral skeletons and makes survival hard for shellfish.
Some bacteria convert nitrogen into usable forms for plants; others return nitrogen gas to the atmosphere.
What is the difference between natural nitrogen fixation and human-made nitrogen fixation?
Natural fixation is done by bacteria or lighting. Human-made fixation is when people make nitrogen fertilizer in factories.
What happens if there is too much carbon dioxide in the atmosphere?
Too much carbon dioxide traps heat, causing global warming and harming ecosystems.
How does too much carbon dioxide affect the oceans, and what can happen to marine life?
Extra CO2 makes oceans more acidic, harming coral reefs and shellfish.
Why is it important for humans to reduce carbon emissions and protect forests?
To balance the carbon cycle and reduce climate change risks.
What might happen to plants and animals if nitrogen-fixing bacteria disappeared?
Plants would struggle to get nitrogen, causing poor growth and affecting animals that depend on plants.
Why do farmers need to be careful when using nitrogen fertilizers?
Overuse can cause water pollution and damage ecosystems.