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 an inherited disease. For someone to get cystic fibrosis, both parents must be carriers of the gene that causes it and then pass it on. That means 25% of the children of such parents will have cystic fibrosis.Boys and girls are equally likely to get the disease.About 10 million Americans carry the gene and do not know it.ystic fibrosis is a genetic disease, meaning it is caused by a person's genes. It affects the glands that produce mucus and sweat, causing mucus to become thick and sticky. As the mucus builds up, it can block airways in the lungs. This makes it increasingly difficult to breathe.