Flu vaccines need to be revised and changed every year because the flu virus constantly mutates. Flu viruses can change in two ways: drift or shift. Antigenic drift occurs when genes of the virus slowly change during replication until the immune system no longer recognizes it. On the other hand, antigenic shift occurs when a major change in the virus happens. This usually leads to a totally different kind of virus. This is what happened during the H1N1 scare in 2009.
DNA viruses like mumps are less prone to mutation due to the presence of DNA polymerase. RNA viruses are more prone to mutation because they undergo reverse transcription to simulate the role of DNA.
Answer:
False I think sorry if it is wrong
Wear safety protection, Make sure you have a fire extinguisher, Follow the instructions, Listen to the instructor/teacher
I would say Upper Respiratory Infection. other wise known as ( URI )
ANSWER:
THE THREE LAW OF MOTIONS ARE LAW OF INERTIA, LAW OF INTERACTION & LAWW OF MASS AND ACCELERATION
- Law of Inertia - An object at rest and an object in motion stays in motion with the same speed and in the same direction.
- Law of Interaction - For every action, there is an equal but opposite reaction.
- Law of Mass and Acceleration - The acceleration of an object as produced by a net force is directly to the magnitude of the net force and inversely propotional to the mass of the object.
<em>F= ma ; a=F/m</em>
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wherein;
<em>F= Force (N)</em>
<em>m= mass (kg)</em>
<em>a= acceleration (m/s^2)</em>
