Plants obtain the carbon used in the manufacture of organic compounds from carbon dioxide (CO2) in the atmosphere.

Here's how it works:

* Photosynthesis: Plants use a process called photosynthesis to convert light energy from the sun into chemical energy stored in the form of glucose (a sugar).

* Carbon Dioxide Absorption: During photosynthesis, plants take in carbon dioxide from the atmosphere through tiny pores on their leaves called stomata.

* Carbon Fixation: The carbon dioxide molecules are then combined with water (H2O) in a series of complex chemical reactions. This process "fixes" the carbon from the CO2 into organic compounds.

* Glucose Production: The end product of photosynthesis is glucose, a simple sugar that serves as the basic building block for other organic compounds.

So, in essence, plants use the carbon from the air to create the building blocks for their bodies, such as sugars, proteins, and fats.