When two genes from two different people are sequenced and aligned, it is discovered that there are multiple sequence differences in the coding segment DNA level. However, when the proteins formed by the genes have their amino acids sequenced, there is no difference observed between the two. What is the most likely explanation for this observation?

(A) The mutations are repaired at the mRNA level after transcription has occurred, but before translation.

(B) RNA processing removes the different segments from the mRNA molecules of each person prior to translation.

(C) The mutations lie at locations where they don't affect protein sequence due to degeneracy of the genetic code.

(D) Mutations at the DNA level are not reflected in proteins produced.

(E) The mutations are corrected at the protein level after translation has occurred.

The best answer to the question: What is the most likely explanation for this observation, would be, B: RNA processing removes the different segments from the mRNA molecules of each person prior to translation.

Explanation:

In order for cells to work, they depend on one of the four major macromolecules; proteins. These proteins are the messengers that carry out genetic commands from the DNA and they will ensure that all processes, including transcription and translation of new proteins, are carried out correctly. In order to produce proteins, the first step is for the DNA to be transcribed into mRNA, a nucleic acid that carries out the information on the DNA for protein generation. Once transcription stops, mRNA undergoes a series of clipping and reorganizing steps that will ensure that when it is decoded for protein formation, the process will be successful. These control steps are all part of the RNA processing mechanism that enures mRNA will successfully be translated into working proteins.

The reason why from genes of different people, a very similiar protein chain may result, is also explained from the fact that codons (a grouping of three nucleotides present in mRNA), when read by ribosomes, and coupled by tRNA, can pair these codons with similar amino acids. Thus, one codon, or similar codons, may code for a singular amino acid. However, mechanisms in the cells prevent these kinds of anomalies, by repairing the mRNA sequence before it is translated into protein.