Can humans be infected by animal viruses? Pupils explore the phenomenon of viral evolution and learn about how animal viruses sometimes adapt to infect humans. They see how viruses are transmitted and what pathogens need to survive. The...

Bacteria are pesky little organisms that can often easily infect us. But how? Salmonella bacteria literally gets under our skin. Viewers see how the dangerous bacteria protects itself from defense mechanisms inside the cell.

Many define biology as the study of life but can't agree on a definition of life. Trying to explain all of the domains and subdomains of biology seems a bit easier than defining life. See a full map of the topics covered by the general...

How cytotoxic T cells get activated by MHC-I/antigen complexes and then proceed to kill infected cells. [10:05]