List of top General Biology Questions on Microbial diseases and host-pathogen interactions

A 0.1 mL aliquot of a bacteriophage stock having a concentration of \(4 \times 10^9\) phages mL\(^{-1}\) is added to 0.5 mL of E. coli culture having \(2 \times 10^8\) cells mL\(^{-1}\). The multiplicity of infection is \(\underline{\hspace{1cm}}\).