Growing degree-day. Growing degree days (GDD), also called growing degree units (GDUs), are a heuristic tool in phenology. GDD are a measure of heat accumulation used by horticulturists, gardeners, and farmers to predict plant and animal development rates such as the date that a flower will bloom, an insect will emerge from dormancy, or a crop will reach maturity.
Cystic fibrosis is a genetic condition caused by a faulty gene (known as the CFTR gene). The CFTR gene normally creates a protein that moves salt and water out of a cell.If the CFTR gene is defective, it results in a build-up of thick, sticky mucus in the body's tubes and passageways.ystic fibrosis is a genetic condition caused by a faulty gene (known as the CFTR gene). The CFTR gene normally creates a protein that moves salt and water out of a cell.
Genes are found on structures in the cells of the body called chromosomes. Each cell normally contains 46 total, or 23 pairs of chromosomes. The seventh pair of chromosomes contains a gene called the cystic fibrosis transmembrane regulator (CFTR) gene.Mutations or errors in this gene are what cause CF.This gene is quite large and complex.ore than 1,800 different mutations in this gene have been found that cause CF. According to the Cystic Fibrosis Foundation, the risk for having a mutation in the gene for CF depends on your ethnic background if you have no family history of CF: Ethnic Background. Risk of CF Mutation.