Why are dead or weakened viruses used instead of normal viruses to create a vaccine?

What are the probable phenotypes of their offspring

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?

Anurse is preparing to administer ampicillin 500 mg in 50 ml of dextrose 5% in water (d5w) to infuse over 15 min. the drop factor of the manual iv tubing is 10 gtt/ml. the nurse should set the manual iv infusion to deliver how many gtt/min? (round the answer to the nearest whole number. use a leading zero if it applies. do not use a trailing zero.)