Answer:
All living organisms share several key characteristics or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing. When viewed together, these characteristics serve to define life.
Transport of a substance from the lumen (cavity) of an organ into one side of a cell and out the other side of the cell into the extracellular fluid is called <u>transcellular transport</u>.
The two routes of transport of substances across the epithelium of the gut are by transcellular method and paracellular method.
Transcellular transport refers to the transport of solutes across a epithelial cell layer through the cells. The best example is the movement of glucose from the intestinal lumen to the extracellular fluid by the epithelial cells. The epithelial cells use the active transport to generate the transcellular transport. Active transport refers to the transport of substances from a region of its lower concentration to a region of its higher concentration against the concentration gradient using cellular energy.