OBJECTIVE LIFE SCIENCE
DIVERSITY AMONG LIFE FORMS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A person’s antibodies level never declines after receiving the vaccine
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People only have passive immunity to the flu for one year
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The flu virus evolves quickly
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The flu virus remains unchanged from year to year
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Detailed explanation-1: -Antigenic drift is an important reason why people can get flu multiple times over the course of their lives. Antigenic drift is also a primary reason why the composition of flu vaccines for use in the Northern and Southern Hemispheres is reviewed annually and updated as needed to keep up with evolving flu viruses.
Detailed explanation-2: -“Influenza viruses have a genome that is made up of RNA, not DNA, and are able to evolve very quickly-up to 1 million times faster than humans and other mammals, ‘’ she says, noting that that’s why global surveillance to track the evolution of these viruses is so important.
Detailed explanation-3: -Because new strains appear frequently, the seasonal flu vaccine usually changes each year, as scientists determine how the virus has mutated and spread.
Detailed explanation-4: -The influenza virus changes over time. This is because of two processes known as antigen drift and antigen shift that cause the virus to change its appearance, which means that from year-to-year, your immune system can no longer recognize and protect you from it.