MAPK/ERK pathway. The MAPK/ERK pathway (also known as the Ras-Raf-MEK-ERK pathway) is a chain of proteins in the cell that communicates a signal from a receptor on the surface of the cell to the DNA in the nucleus of the cell.
Acclimatization or acclimatisation (also called acclimation or acclimatation) is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude, temperature, humidity, photoperiod, or pH), allowing it to maintain performance across a range of environmental conditions.
An accumulator is a function that maintains internal state; when you invoke it with a new value it adds that value to its internal state and returns the new sum. An example usage would be to initialize it to zero and invoke it with each value in an array of integers; the result of the final invocation would be the sum of the integers -- or rather, the accumulation of the values.