microbe
Tiny living organism that can only be seen with a microscope. Some are beneficial, while others can cause diseases.
pathogen
A microorganism that causes disease in its host
Vaccine
These stimulates the immune system to acquire immunity to a specific disease, preventing future infections. They're made from weakened or dead pathogens, synthetic molecules, or parts of pathogens.
Gene Mutation
A change in the DNA sequence that makes up a gene, which may result in altered protein synthesis and function. It can occur spontaneously or due to exposure to mutagens such as radiation, chemicals, or viruses. Can be harmful, beneficial, or have no effect on the individual.