Superficial is a used to describe structures that are closer to the exterior surface of the body. Deep refers to structures closer to the center of the body region. For example, skin is superficial to bones, and bones are deep to skin.
The sun is the most basic source of energy for all living beings. It supports photosynthesis in plants and algae that is the main reaction for producing energy rich compounds like carbohydrates etc. These compounds are utilized by all life on Earth to stay alive.
A nucleotide consists of all of the following except a nitrogenous base. The are of course the main building blocks of genetic information in many life forms.
