Khan Academy
Khan Academy: Phagocytosis
Have you ever wondered how a virus or other infectious agent invades a cell to start an infection? Some objects, like viruses, bacteria, or other particles are too large to transport through the plasma membrane. So, cells engulf the...
McGraw Hill
Glencoe Biology: Bacteria and Viruses: Chapter Test Practice
Ten multiple-choice test practice questions covering bacteria and viruses. Students have the opportunity to check their answers after submitting their results.