Question

An unusually dangerous strain of flu that infects humans was reported from China in the spring of 2013. The strain is called H7N9. In this coding scheme, H and N refer to ________ and ________ proteins.

Answer 1

The 'H' and 'N' in the H7N9 influenza strain refer to hemagglutinin and neuraminidase, respectively, which are proteins that facilitate the viral infection process.

Step-by-step explanation:

In the coding scheme for influenza viruses, H refers to hemagglutinin, and N refers to neuraminidase, which are both spike proteins on the surface of the virus. These proteins are critical in the virus's ability to infect host cells; hemaglutinin allows the virus to attach to and enter host cells, while neuraminidase enables the release of new virions from the host cell. Influenza A viruses are particularly notable for their potential to cause pandemics and are classified by the specific types of proteins they carry. For instance, the H7N9 strain mentioned is serologically characterized by the type of H and N proteins it possesses. Monitoring and surveillance of such strains are vital due to their ability to mutate, potentially leading to epidemics with high mortality rates.