Scientifically, the term buffalo is incorrect for the North American species; its proper Latin name is Bison bison. However, common usage has made the term buffalo an acceptable synonym for the American bison. (from The American Buffalo in Transition, by J. Albert Rorabacher.).
Life cycle. Life cycle, in biology, the series of changes that the members of a species undergo as they pass from the beginning of a given developmental stage to the inception of that same developmental stage in a subsequent generation.
Life expectancy is defined statistically as the average number of years remaining for an individual or a group of people at a given age. Longevity refers to the characteristics of the relatively long life span of some members of a population. Moreover, because life expectancy is an average, a particular person may well die many years before or many years after their expected survival.