Study Outline. 1  Microbiology-An Introduction. 2  Microbiology is the study of organisms too small to be clearly seen by the unaided eye (i.e., microorganisms); these include viruses, bacteria, archaea, protozoa, algae, and fungi.tudy Outline. 1  Microbiology-An Introduction. 2  Microbiology is the study of organisms too small to be clearly seen by the unaided eye (i.e., microorganisms); these include viruses, bacteria, archaea, protozoa, algae, and fungi.
Well, according to the CIA's The World Factbook, the current average human lifespan is approximately 66 and a half years. On average the current life expectancy for the world is about 67.2 years.
Individuals between 15 and 64 years of age make up 65.9% of the population, and another 7.9% are 65 or older. The World Health Organization suggests that the global average life expectancy is 70.5 years, with men living to 68 and women to 73 years of age. The sex ratio of the world is as follows: for every 1.01 males, there is one female.