Infectious Humor: A retrovirus carries genetic information in the form of RNA instead of DNA. A genetic throwback of sorts, since usual mechanism is DNA → RNA → protein. Retroviruses need an extra step: RNA → DNA → RNA → protein. According to the RNA World hypothesis, RNA is the earliest genetic material.
The virus type on the left is a bacteriophage. The one on the right is going through a hippie phage.
via Neural Stem World Community on FB. #scienceeveryday