Which structural feature of the cell membrane allows molecules such as oxygen and carbon dioxide to diffuse into and out of the cell

phospholipid bilayer

Explanation:

The phospholipid bilayer is a structure of the cell membrane that is semi-permeable and allows molecules to move into and out of the cell. Small uncharged polar molecules such as oxygen and carbon dioxide diffuse into the cell quickly. However, large uncharged polar molecules and ions cannot diffuse into the cell.

Hope that helps.

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.