Which of the following are common features of expression vectors?
a. small segments of dna that encode tags for protein purification.
b. transcriptional start and stop sites
c. a tightly controlled promoter than can only be induced under certain circumstances
d. antibiotic resistance gene
e. all of the above are common features of expression vectors

Name the organs of humanelemintary canal.

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

How did alexander fleming’s research solve a societal problem? he developed ways to treat inherited diseases. he advocated for regular hand washing to kill germs. he discovered a new type of medicine that could treat infections. he discovered the cause of mad cow disease, an emerging disease.