Although scientists do not know the exact origin of eukaryotic cells, the theory does explain the origin of the mitochondria and chloroplasts.

4emphysema is a health condition in which the lungs can no longer expel carbon dioxide normally. as a result, a person who has emphysema may have high blood acidity levels. the body process that would attempt to return the blood ph to normal so that cells could function properly is called a. active transport b. acidosis c. homeostasis d. adaptation