Insulin. Insulin is a hormone made by the beta cells in the pancreas. It is the key that opens the doors of cells and allows glucose to get into the cell. Each cell needs glucose to function. Carbohydrates in food are broken down into glucose which enters the blood stream.
The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants.
Pergelic soils have mean annual soil temperatures less than 0 C (32 F) and may be in Arizona at the highest elevations of the San Francisco Peaks. The distribution of the four soil temperature regimes throughout Arizona is shown in Plate 14.