Von Magnus phenomenon:
Ans. is 'd' i.e., Virus yields has high Hemagglutination low infectivityIncomplete viruses: Due to defect during assembly of viral components, some of the daughter virions that are produced may not be infective. Example of such incomplete virus is the influenza virus that shows a high Hemagglutination titer but with a low infectivity. This is known as von Magnus phenomenon.
Is a normal replicative cycle
Virus yield has low Hemagglutination
Virus has high infectivity
Virus yields has high Hemagglutination low infectivity
Virology