What does DNA sequencing determine?

• A. The structure of proteins
• B. The exact nucleotide order in DNA
• C. The number of genes present in DNA
• D. The function of various ribonucleic acids

Answer: (B)

The correct answer is that DNA sequencing determines the exact nucleotide order in DNA. This process involves analyzing a sample of DNA to identify the sequence of its nucleotides, which are the building blocks of DNA. The nucleotides consist of adenine (A), cytosine (C), guanine (G), and thymine (T). By determining the order of these bases, researchers can gain profound insights into genetic information, including the potential coding for proteins, regulatory elements, and variations that may contribute to different traits or diseases.

While the presence of genes, protein structures, and the functions of various types of RNA are important aspects of genetics and molecular biology, these elements cannot be directly determined solely from sequencing DNA. Instead, the sequence data can be further analyzed to infer gene locations, predict protein-coding regions, and investigate the roles of RNA, but the fundamental output of DNA sequencing is the precise arrangement of the nucleotides within the DNA molecule.