By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
Answer:
b
Explanation I took a test
It is important so that the diffusion distance is shortened so gas exchange occurs more efficient.
As you may already know, lungs are used for gas exchange, and the alveoli is the surface for gas exchange. Gas exchange is where carbon dioxide from the blood capillaries (on the alveoli) are diffused into the alveoli, while the new oxygen that we breathed in are diffused to the capillaries.
Since the whole has exchange process relays on diffusion, so diffusion must happened fast in order to increase the efficiency. Therefore, the alveoli is only one cell thick so carbon dioxide and oxygen has a shorter distance to diffuse through so more of these gas can be exchanged.
CNS contains brain and spinal cord
Answer:
Water is split during the light reaction to form oxygen
Explanation:
The hydrogen ions formed are super important for photosynthesis. They will be used to create ATP molecules. The ATP molecules will be used later on in the dark reaction (also called the Calvin cycle). The ATP molecules allow the plant cell to assemble carbon based molecules like glucose.