Guard cells use osmotic pressure to open and close stomata, allowing plants to regulate the amount of water and solutes within them. In order for plants to produce energy and maintain cellular function, their cells undergo the highly intricate process of photosynthesis
The two cells of the similar shape, and size have different levels of the ongoing metabolic activity. On one hand, the cell a is metabolically quiet, which means that no energy consuming chemical reactions are taking place in this cell. On the other hand, the cell b is actively consuming the surrounding oxygen. In this scenario, the oxygen will more quickly diffuse into the cell b because the diffusion gradient for oxygen in this cell is steeper than in the cell a.
Hence, the blanks can be filled with 'b and the diffusion gradient is steeper' respectively.
Okay. About 71% of the Earth's surface is water. And salt water holds about 96.5% of all the Earth's water. The remaining 3% of freshwater is found in Glaciers and ice caps making it difficult to use because it is frozen. Other places freshwater can be found is: Lakes, swamps, rivers and the atmosphere. I hope this helps!
I think it is D but I might be wrong !!! Hope I help !!