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.
The first thing you need to realize is that cystic fibrosis (CF) is a genetic disease. Each human being has 23 pairs of chromosomes in each cell of the body.It is a mutation on the seventh pair that causes CF. This gene is very complex, and well over 1,000 different kinds mutations on this gene can manifest as CF.s a genetic disorder, it is passed along from parents to child. In the case of CF, two CF genes must be inherited, one from each parent. This makes CF a recessive disorder, because two genes are needed for the condition to manifest.