Which process is primarily responsible for the sudden emergence of new pandemic influenza virus strains?

• A. Genetic recombination in bacteria
• B. Antigenic shift
• C. Antigenic drift
• D. Horizontal gene transfer in fungi

Answer: (B)

Verified step by step guidance

1. Understand that influenza viruses can change over time through genetic changes, which affect how the immune system recognizes them.
2. Recognize that 'antigenic drift' refers to small, gradual mutations in the virus's genes that happen continuously, leading to minor changes in virus surface proteins.
3. Know that 'antigenic shift' is a sudden, major change in the influenza virus, usually caused by the reassortment of gene segments when two different influenza viruses infect the same cell.
4. Identify that antigenic shift can create a new influenza virus strain with novel surface proteins, to which the human population has little or no immunity, potentially causing a pandemic.
5. Distinguish that genetic recombination in bacteria and horizontal gene transfer in fungi are processes relevant to those organisms but are not responsible for the sudden emergence of new pandemic influenza virus strains.