Polymerase chain reaction (pcr) is an essential technique for the study of dna. pcr uses a dna polymerase enzyme from thermophilus aquaticus to amplify dna extracted from any sample. in order for the reaction to work, researchers must transfer microliters of sample to the reaction vessel for pcr. if a researcher has a dna sample with a concentration of 0.28 micrograms per microliter, how many microliters of dna must be transfered to conduct a 50 microliter reaction if the final concentration should be 2.2 nanograms per microliter?

Christie's doctor recommends that she eat 40 grams of protein a day. she's already consumed 50% of her protein recommendation for the day. how many servings of the given snack should christie have to meet her daily protein recommendation?

Subduction zones form when an oceanic plate collides with another oceanic plate or continental plate. the continental crust is lighter and less dense than oceanic crust. continental crust's density is approximately 2.7 grams per cubic centimeter. oceanic crust is thinner and the average density is about 3.3 cubic centimeters. when the two crustal plates converge the oceanic plate always bends and subducts beneath a continental plate. once the oceanic crust subjects, the rocks are subjected to changes in heat and pressure. because of this, we would expect to find rocks in the area of a subduction. a) clastic b) igneous c) metamorphic d) sedimentary

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.