Viral infection. Image showing a virus (blue and pink spheres) infecting a host cell (yellow). The virus particles release genetic material (turquoise chains) into the cell. This travels to the cell nucleus where it combines with the cell's genetic material. The cell then reads the genetic instructions and the cell's biochemical mechanisms build new virus particles. These new virus particles erupt (right) from the cell, killing it. The viral infection spreads as the cycle repeats.