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.
Life expectancy, the average number of years a human is expected to live, varies due to many factors including current age, gender, race, and geographic location. The average life expectancy for a 67 year old is 17.4 years. The top three causes of death among people this age are cancer, heart disease, and chronic lower respiratory diseases which contribute to an average death probability of 0.01565%.