1 the set of exogenic (physical, chemical and biological) processes that alter the physical and chemical state of rocks at or near the earth's surface.  intensity of most weathering decreases with depth, because variations in temperature and moistures decrease with depth.
A gene is a segment of nucleic acid that contains the information necessary to produce a functional product, usually a protein. Genes consist of a long strand of DNA (RNA in some viruses) that contains a promoter, which controls the activity of a gene, and a coding sequence, which determines what the gene produces.
The cell's deoxyribonucleic acid (DNA) contains all the genetic material of the cell, comprised of segments called genes. Each DNA gene contains the instructions for producing one specific protein. Messenger RNA is a copy of one section, or gene, of DNA. This mRNA contains triplets of nucleotides, called codons. Each of these codons represents one amino acid.