A beacause not everything happens to all cells
The basic pattern of breathing is established by the DORSAL RESPIRATORY GROUP located in the MEDULLA OBLONGATA.
A volcanic winter is a reduction in global temperatures caused by volcanic ash and droplets of sulfuric acid and water obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, particularly explosive volcanic eruption.
They are important because they contribute to clean air and water for 500 million people this is because they help sustain a healthy forest
The answer to this is C because humans don't have cell walls and if you are looking at an onion it has a cell wall because it is a plant.
