The endocrine component of the pancreas consists of islet cells (islets of Langerhans) that create and release important hormones directly into the bloodstream. Two of the main pancreatic hormones are insulin, which acts to lower blood sugar, and glucagon, which acts to raise blood sugar.
Variability is a measure of the spread of a data set. Learn more about the different measures of variability including the range, variance, and standard deviation, and how they are used in the field of Psychology.
Phenotypic variation, then, is the variability in phenotypes that exists in a population. For example, people come in all shapes and sizes: height, weight, and body shape are phenotypes that vary. Hair, eye color, and the ability to roll your tongue are variable phenotypes, too.