The Carbon Cycle Flashcards
What is the carbon cycle?
It is the process by which carbon atoms are transferred between living organisms and the environment through processes like respiration, feeding, decomposition, and combustion.
What percentage of the Earth’s atmosphere is carbon dioxide?
About 0.04%.
How do plants obtain carbon from the atmosphere?
Through photosynthesis, where they use carbon dioxide to make carbohydrates, proteins, and lipids.
How do animals obtain carbon?
By eating plants or by eating animals that have eaten plants.
What process releases carbon dioxide back into the atmosphere from plants and animals?
Respiration
What happens to waste materials and dead bodies in the carbon cycle?
Decomposers like bacteria and fungi feed on them and incorporate carbon into their own bodies.
How do decomposers contribute to the carbon cycle?
Through respiration, they release carbon dioxide back into the atmosphere.
What happens in waterlogged soils where there is little oxygen?
Decomposers can’t fully break down tissues, so the remains accumulate and may eventually form fossil fuels.
How are fossil fuels like coal, oil, and natural gas formed?
From partially decomposed remains of ancient plants and animals that accumulated in swamps and oceans millions of years ago.
What is combustion, and how does it affect the carbon cycle?
Combustion is the burning of fossil fuels, which releases carbon dioxide into the atmosphere.
Why are plants important in the carbon cycle?
They remove carbon dioxide from the atmosphere during photosynthesis, making carbon available to animals. Without plants, carbon would not be recycled effectively.
What would happen if there were no plants in the carbon cycle?
Carbon would remain in the atmosphere, and animals could not obtain the carbon they need to survive.
What are the three ways carbon is returned to the atmosphere?
Respiration, decomposition, and combustion.
What is happening to the level of carbon dioxide in the air?
It has been rising steadily.
What major human activity contributes to the rising carbon dioxide levels?
The burning (combustion) of fossil fuels to produce energy for machines and industries.
How long was carbon locked away in fossil fuels before being released?
For millions of years in solid or liquid fossil fuels.
What effect does increased combustion of fossil fuels have on the environment?
It raises the concentration of carbon dioxide in the atmosphere, contributing to global warming.
What is the Industrial Revolution?
A period that began about 200 years ago when people began using machines to do work, increasing the demand for energy.
What energy source was primarily used during the Industrial Revolution?
Fossil fuels (coal, oil, natural gas).
Why did fossil fuel use increase during the Industrial Revolution?
To power machines for manufacturing, transportation, and other industries.
How does human population growth affect the carbon cycle?
More people lead to increased industrial activity and energy use, which results in more fossil fuel combustion and CO₂ emissions.
What is the connection between fossil fuels and carbon dioxide?
Burning fossil fuels releases carbon dioxide that was trapped underground for millions of years.
Why is carbon important?
Carbon compounds regulate the Earth’s temperature, make up the food that sustains us, and provide energy that fuels our global economy.
