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Primary Role of DNA in Biology: Genetic Storage Protein Instructions?

What Does DNA Do in Cells: Heredity Info Protein Synthesis Explained

DNA’s core function stores genetic information in nucleotide sequences to guide protein synthesis via transcription/translation—not lipid metabolism, membranes, or energy—fundamental concept for General Biology certification exam success.

Question

What is the primary function of DNA in biological systems?

A. DNA facilitates lipid metabolism and synthesis.
B. DNA stores genetic information and instructs protein synthesis.
C. DNA acts as a structural component in cell membranes.
D. DNA provides energy storage for cellular activities.

Answer

B. DNA stores genetic information and instructs protein synthesis.

Explanation

DNA, or deoxyribonucleic acid, primarily functions as the hereditary material in nearly all organisms by storing genetic information in the sequence of its nucleotide bases (adenine, thymine, cytosine, guanine), which encodes instructions for building and maintaining life through the double-helix structure that enables precise replication and stability. This information flows via the central dogma—DNA transcription into messenger RNA (mRNA) in the nucleus, followed by mRNA translation at ribosomes into proteins using transfer RNA (tRNA)—directing cellular processes like enzyme production, structural components, and regulatory factors essential for growth, reproduction, and adaptation. Unlike lipids (for metabolism/membranes), membrane phospholipids, or energy-storage glycogen/ATP, DNA’s role centers on information repository and transmission, with mutations altering base sequences to drive evolution while repair mechanisms preserve fidelity.