The body system that directly provides for this demand is the circulatory system. When you exercise, the circulatory and muscle system cooperate, in order to meet the increased needs for strength and energy. The circulatory system involves the network which delivers blood to every part of your body. This flowing of blood ensures that the tissues are oxygenated and rich in necessary nutrients. During exercise, more blood flows to and from your muscles, in order to deliver the necessary amounts of oxygen to complete the aerobic respiration.
A population consists of all the organisms of a given species that live in a particular area
It seems that you have missed the necessary options to answer this question, but anyway here is the answer. Since the person spends several days in a hot, dry desert environment with little water available to drink, the kidneys' function during this time is that, the amount of urine produced is decreased in order to maintain the proper amount of water in the bloodstream. Hope this answer helps.
