Answer: Two people can have different DNA sequences but these sequences can code for the same amino acids due to the redundancy of the genetic code in which two different codons can code for the same amino acid.
Explanation:
The genome of an organism is found in a molecule called DNA (deoxyribonucleic acid). The main function of this DNA molecule is the long-term storage of information to build other components of cells, such as proteins and RNA molecules (ribonucleic acid); and the portion of the genome that codes for a protein or RNA is known as a gene. These protein-coding genes are composed of trinucleotide units called codons, each of which codes for an amino acid. For a protein whose sequence is encoded in the nucleotides of DNA to be synthesized, that DNA molecule must first be transcribed into a molecule called messenger RNA, and this molecule is used for a process called translation or protein synthesis. The sequence of the genetic material is composed of four distinct nitrogenous bases, which are represented by letters in the genetic code:
- Adenine (A)
- Thymine (T)
- Guanine (G)
- Cytosine (C)
- Uracil (U) instead of T in RNA
<u>The genetic code is the set of rules that defines how a sequence of nucleotides in RNA is translated into a sequence of amino acids in a protein</u>. This code is common to all living things, which shows that it has had a unique origin and is universal. So, the code defines the relationship between each sequence of three nucleotides (codon) and each amino acid. The number of possible codons is 64, of which 61 code for amino acids (one of them being the start codon, AUG) and the remaining three are stop sites (UAA, UAG, UGA). The codon sequence determines the amino acid sequence in a particular protein, which will have a specific structure and function.
However, the genetic code has redundancy but no ambiguity. For example, two different codon can code for the same amino acid, and the differences between codons encoding the same amino acid have differences in the third position. <u>This is explained by the wobble effect, where the same anticodon (present in the transfer RNA that loads with the amino acid and interacts with the codon in the messenger RNA) can establish interaction with different codons, which differ in their third base</u>. This is why, in general, tolerance to change at this position is greater than at the first and second positions, and therefore tends to be less represented in the case of variations that result in pathologies.
Thus, two people can have different DNA sequences but these sequences can code for the same amino acids due to the redundancy of the genetic code in which two different codons can code for the same amino acid.
