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.
Each gene is a specific segment of DNA, occupying a fixed place on a chromosome. Genes contain the chemical information needed to create different kinds of proteins.ene - (genetics) a segment of DNA that is involved in producing a polypeptide chain; it can include regions preceding and following the coding DNA as well as introns between the exons; it is considered a unit of heredity; genes were formerly called factors. cistron, factor.