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.
Genes are segments of DNA on a chromosome. Each gene is made up of a sequence of four different chemical bases (adenine, thymine, cytosine and guanine). The specific sequence determines which protein the cell will build, much as the specific sequence of letters determines words and sentences.very cell in your body contains DNA (deoxyribonucleic acid). DNA, the genetic code for your body, exists as two long, paired strands spiraled into a double helix called a chromosome.