What is the function of the cell's selectively permeable membrane?

If bacteria are much too small to see, what is one reason why can we see colonies in the petri dishes that have plenty of food to eat after only a few days?

Amylase becomes denatured at a temperature of 80°c. during an experiment to study the effect of varyingtemperature on enzyme activity, amylase’s reactivity with starch was measured at body temperature (37°c), andthen again at an increased temperature of 42°c. how would this increase in temperature affect the experiment

9. which of these are considered standard precautions for dealing with bodily fluids? check all that apply wearing gloves when providing patient care that may involve contact with blood checking a patient's chart to determine if there is a harmful blood disorder wearing aprons, masks, and protective eyewear when needed transporting a patient from a bed to a wheelchair to take him or her to a procedure washing hands when required cleaning equipment thoroughly before using it on the next patient