Question

what would most likely happen to life on earth if the carbon cycle stopped?
life would continue unchanged.
life would cease to exist.
only plants would be affected.
only animals would be affected.

Explanation:

Carbon is a key element for life - it is part of organic compounds like carbohydrates, proteins, lipids and nucleic acids. The carbon - cycle is essential for recycling carbon between the atmosphere, biosphere, hydrosphere and geosphere. Without it, plants couldn't perform photosynthesis (which requires carbon dioxide), and animals couldn't get the carbon - containing nutrients they need from plants or other animals. So life would cease to exist.

Answer:

Life would cease to exist.