The nucleotide sequence on a section of
DNA where transcription begins is called a promoter.
To add, i genetics, a promoter is a region
of DNA that initiates transcription of a particular gene. Promoters are found along
the transcription beginning sites of genes, on the same strand and upstream on
the <span>DNA.</span>
The flu vaccine changes every year. The flu vaccine is based on a predicted strain that is anticipated to be the most infectious that year. Thats why people who sometimes get the vaccination still get the flu, they don't have the antibodies for the strain they were infected with. Strains for viral disease don't change very much and usually the vaccination for them cover them well.
It is important because the results would not be reliable since other variables you are not testing could have been in affect.
Hope this helps(;
