Is it true that the unltimate sorce of energy of all living things is the leaf?

The ultimate source of energy for living things is the Sun. Plants and other photosynthetic organisms take the energy from sunlight to make glucose. Glucose is a simple sugar with the molecular formula C6H12O6. Glucose circulates in the blood of animals as blood sugar. It is made during photosynthesis from water and carbon dioxide, using energy from sunlight.

Everything that you need in a lab is in your lab

It is called the medulla oblongata or people usually call it medulla. it is the lower half of the brain stem continuous with the spinal cord.