Q1. To set up a link between specific bacterium and skin disease, researchers have shown that a bacterium was present in sick persons but not in healthy individuals. They isolated bacterium in a pure culture and demonstrated that experimental healthy animals injected with this culture became sick. What other test do researchers require to perform to be absolutely sure that the bacterium is responsible for the disease?

Q2. Mitochondira are thought to be descendants of certain alpha-proteobacteria. They are, however, no longer able to lead independent lives because most genes originally present on their chromosome have moved to the nuclear genome. Which phenomenon accounts for movement of these genes?