Kaplan Nursing Entrance Practice Exam

All organisms utilize which of the following to produce proteins?

1. A single triplet genetic code

2. A double genetic code

3. A triplet genetic code

4. A circular genetic code

The correct answer is: A triplet genetic code

All organisms utilize a triplet genetic code to produce proteins. This code is based on sequences of three nucleotides, known as codons, found in the messenger RNA (mRNA). Each codon corresponds to a specific amino acid, which are the building blocks of proteins. This universal property of the genetic code means that the same sequences of nucleotides translate into the same amino acids across different species, highlighting the fundamental similarities in the mechanisms of life. The triplet coding system allows for a vast variety of proteins to be synthesized, as there are 64 possible codons that can code for just 20 different amino acids, along with start and stop signals for protein synthesis. This redundancy is crucial for biological processes because it helps protect organisms from mutations that might otherwise disrupt protein synthesis by providing alternative codons that can still encode the same amino acids. The other options, including a single triplet genetic code, a double genetic code, and a circular genetic code, do not accurately describe how all organisms produce proteins. A single triplet implies only one triplet codes for all proteins, which is incorrect, while a double genetic code suggests that two distinct coding systems are in use simultaneously, which does not apply universally. Lastly, a circular genetic