Common medical problems such as heart disease, type 2 diabetes, and obesity do not have a single genetic cause—they are likely associated with the effects of multiple genes (polygenic) in combination with lifestyle and environmental factors.
Glucagon and Insulin are both hormones that regulate blood sugar levels and they are both produced by the pancreas.
When sugar levels in the blood are high the pancreas secretes insulin from its beta cells and releases it into the blood stream. Insulin causes the red blood cells, fat cells and muscle cells to absorb sugar from the blood .
When sugar levels are low, the pancreas secrets glucagon from its alpha cells which stimulates the liver to release the glucose that is stored in its cells.
Thus these two hormones work in the body to keep sugar levels balanced.
Unicellular organisms are devoid of circulatory systems and will be found living in moist or watery environments to facilitate uptake of nutrients and gases and expulsion of waste by the process of diffusion.
Their cell is structured such that it can engage in direct exchange of substances with its environment. Water serves as the perfect medium or environment through which this exchange can occur.
Gases and nutrients simply diffuse into the cell or are moved into the cell by means of active transport or phagocytosis.
