Why are micro-organisms such powerful pathogens?
Size and distribution: Being so small, many micro-organisms can fit into a small space, or spread out (thinly!) over a large area, although most are not able to move of their own accord. Reproductive potential: Because they can multiply rapidly, it only takes a few bacteria or viruses to cause an infection. Usually, micro-organisms reproduce asexually, so they can produce millions in a few hours. Variability: With such large potential populations, new varieties can arise due to mutation, and characteristics like resistance to antibiotics can spread easily, even between unrelated species! Insidiousness: They cannot be seen directly, and whilst reproducing and preparing to spread they can cause great damage to cells and internal working parts of organisms.
