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.
- a section of DNA that contains the genes for the proteins needed for a specific metabolic pathway, (responds to changes in the environment) - a unit of gene regulation and transcription in bacterial DNA that consists of a promoter, an operator, and one or more structural genes. a section of DNA that contains the genes for the proteins needed for a specific metabolic pathway, (responds to changes in the environment) - a unit of gene regulation and transcription in bacterial DNA that consists of a promoter, an operator, and one or more structural genes.