In the process some of the mass of the hydrogen atoms is converted into energy in the form of light. The same process occurs in thermonuclear (fusion) bombs. In the Sun the process occurs in a controled manner. In a bomb it happens all at once in a big chain-reaction explosion.
Phloem. Definition. noun. A tissue in a vascular plant that functions primarily in transporting organic food materials (e.g. sucrose) from the photosynthetic organ (leaf) to all the parts of the plant.
Plant Vascular System Development . Xylem and phloem are the conducting elements of vascular plants. They function in the transport of water, nutrients, sugars, proteins and RNA throughout the plant. The xylem and phloem are generally found together in vascular bundles and can lie in various positions relative to each other.