the discoveries, events and people that continue to affect the history ... The extremely infectious disease was class-blind, killing rich and ... that a few cells remaining in Petri dishes could be used as biological weaponry. ... smallpox, a disease that had now been killing unhindered for at least 2,800 years.
Smallpox has had a major impact on world history, not least because indigenous populations of regions where smallpox was non-native, such as the Americas and Australia, were rapidly decimated and weakened by smallpox (along with other introduced diseases) during periods of initial foreign contact, which helped pave the way for conquest and colonization.
It is important for the cell to be able to bring necessary nutrients immedriately where it needs to and to be able to dispose of harmful byproducts of the cell process. It is equally important to be able to regulate water concentration.