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.
Cystic fibrosis is a genetic disease. People with CF have inherited two copies of the defective CF gene -- one copy from each parent. Both parents must have at least one copy of the defective gene. People with only one copy of the defective CF gene are called carriers, but they do not have the disease.