In transcription: select one:
a. several amino acids are assembled by the messenger rna molecules at one time.
b. a special sequence called a promoter is necessary for transcription to begin.
c. certain polypeptide sequences are governed by one ribosome, while other sequences are produced by other ribosomes.
d. the transfer rna molecules arrange the messenger rna codons into the appropriate sequence.
e. none of these.

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(ii) carbonate, in concentrated sulfuric acid. the sulfuric acid reacts with the copper(ii) carbonate to produce a blue solution of copper(ii) sulfate. scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: (s) (aq) (s) (aq) suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. he adds powdered iron to a copper(ii) sulfate sample from the plant until no more copper will precipitate. he then washes, dries, and weighs the precipitate, and finds that it has a mass of .