The light would be best described as AN UNCONDITIONED STIMULUS.
An unconditioned stimulus refers to any stimulus which naturally evokes a response from the affected person. The response that is evoked is termed unconditioned response. In the question given above, the light is the unconditioned stimulus while the blinking is the unconditioned response.<span />
Invasive species. Native grasses have evolved with the normally-occurring grazing organisms to achieve a level of reproduction which sustains the grasses despite the grazing. An invasive species disrupts this ecological balance that took millions of years to develop by eating the grass at a rate that exceeds the rate for the grass to re-seed itself and maintain its own population. The invasive species easily decimates the grass population.
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.
<span>Dens (odontoid process) Hope this helps.</span>