How is genetic information encoded in DNA?

• A. In the sequence of codons
• B. In the arrangement of amino acids
• C. In the sequence of nucleotides
• D. In the structure of proteins

Answer: (C)

Genetic information is encoded in DNA through the sequence of nucleotides, which are the building blocks of DNA. Each nucleotide consists of a sugar molecule, a phosphate group, and a nitrogenous base. The specific order of these nucleotides along the DNA strand determines the genetic code. This sequence dictates which proteins are synthesized in a cell, ultimately influencing cellular function and organismal traits.

Proteins are made from amino acids, but the direct encoding of genetic information happens at the nucleotide level. Simply put, the DNA sequence is transcribed into messenger RNA (mRNA), which is then translated into a chain of amino acids, forming a protein. Thus, while proteins and amino acids are critical for carrying out the functions dictated by the genetic code, it is the arrangement of nucleotides in the DNA that actually encodes that information.