The sequential series of nucleotide triplets that are positioned in the A site of the ribosome during translation. A. Primary structure B. Exons C. Promoter D. Reading frame

The correct answer is D.

Explanation:

Reading frame is a sequence of codons determined by nucleotides that are read in groups of three from a specific translation start codon, that is, it is a linear sequence of codons or triplets in a nucleic acid. It is one of three possible reading alternatives of a nucleotide sequence of a series of triplets, this means that, in a double-stranded DNA molecule, there are 6 possible directions in which reading frames can be opened; three in the forward direction and three in reverse.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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