It is needed by all living things and every living cell to carry out life processes, such as breaking down and building up molecules, and transporting many molecules across cell membranes. The form of energy that living things need for these processes is chemical energy, and it comes from food.
Upper arm/elbows front side
Where organisms are better adapted to their environments tend to survive and produce more kids!
Treehouses are built on the stem and the three branches, which do not grow in length, only in width. Trees grow in length only in the area of the buds, which are located at the ends of branches.
Maybe it is easier to understand this if you imagine that you put a small house replica on the palm of your hand and that your fingers are constantly growing from their tips. So, the house on your palm would not move, only your fingers, (the analogy to the three top buds) would become longer.