Excretion
Through the cell membrane.
Plasma membrane
"diffusion"
Water, carbon dioxide and oxygen can enter a cell through the plasma membrane.
Decomposers break down organic matter through the process of decomposition, releasing carbon dioxide as a byproduct. This occurs as they metabolize the organic compounds in dead plants and animals, releasing carbon dioxide back into the atmosphere.
Substances that are small, nonpolar, and uncharged will diffuse through a membrane easily. This includes gases like oxygen and carbon dioxide, as well as small lipophilic molecules. Larger or charged molecules may require assistance from transport proteins to cross the membrane.
diffusion
diffusion
diffusion
diffiusion
diffusion
The layers through which respiratory gases diffuse are known as the respiratory membrane. This membrane consists of the alveolar epithelium, basement membrane, and capillary endothelium. The exchange of oxygen and carbon dioxide occurs through this membrane during respiration.