The immune system is a system of many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.o function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.
The cost to run for president in the general election can amount to at least $70 million USD, although the amount of money required can vary. It is possible that at some point in the future, all presidential candidates will run without taking any federal contributions.
The Obama campaign cost the incumbent president, the Democratic Party and the primary super PACs supporting his candidacy more than $1.1 billion in the 2012 presidential race, according to published reports and campaign finance data.he Obama campaign cost an average of $2.9 million per day for 2012. The $1 billion-plus in spending by those entities includes: