Guide. A bone density test measures the density of minerals (such as calcium) in your bones using a special X-ray. This information is used to estimate the strength of your bones.
Animal cells do have vacuoles, but they are smaller, larger in number (plant cells usually have just one or a few large vacuoles) AND serve a somewhat different purpose than those of plants.
For example, vacuoles in stomata cells contain large numbers of potassium ions, which can be pumped in or out to open or close the stomata. Animal Cells In animal cells, vacuoles serve more subordinate roles, such as assisting in endo- and exocytosis or basic storage of food and waste. Central Vacuole The central vacuole is found only in plant cells. It is filled with water and is pressurised, like a balloon. This forces all the other organelles within the cell out toward the cell wall. This pressure is called turgor pressure and is what gives plants their crisp and firm structure.