Examples of homeostasis include the regulation of body temperature, the pH of extracellular fluid, or the concentrations of sodium, potassium and calcium ions as well as that of glucose in the blood plasma, despite changes in the environment, diet, or level of activity.
Blue-collar workers perform labor jobs and typically work with their hands. The skills necessary for blue-collar work vary by occupation. Some blue-collar occupations require highly skilled personnel who are formally trained and certified.
BREAKING DOWN 'Blue Collar'. The term blue collar has in the past implied a certain lack of worker education as well, but those lines are blurred today. Today blue collar workers can be formally educated, skilled and highly paid. They can also earn more annually then some of their white collar counterparts. The rate of college attendance in the U.S. has skyrocketed in the past 100 years, democratizing the education level once reserved for only wealthy families.