Organ system is the most complex in organization
The kidneys.
The kidneys keep blood isotonic by removing excess salt and water through urine.
<span>Thinking of the layers of the earths crust, it would be expected that the mantle is rich in minerals that contain heavy metals such as iron and nickel.</span>
<span>A plant's plastids contain its chlorophyll, which enables it to photosynthesize. If it lost the plastids, it would not be able to photosynthesize, which is the only way it can get food, so it would die.</span>