Answer: A only

The gene sequence directly encodes the primary structure of the protein through the genetic code, making it the most accurate information derivable.

Option Analysis

Primary Structure (A)
The primary structure is the linear sequence of amino acids in the polypeptide chain, determined precisely by the gene’s nucleotide sequence via transcription to mRNA and translation. Each codon specifies one amino acid, so the gene sequence predicts this order exactly, barring rare post-translational changes not encoded in the gene.

Function of Protein (B)
Protein function depends on higher-level folding, interactions, and modifications, which cannot be accurately predicted from gene sequence alone due to complex environmental and conformational factors. Sequence homology offers clues, but direct derivation is unreliable.

Secondary Structure (C)
Secondary structures like alpha helices or beta sheets arise from hydrogen bonding patterns influenced by amino acid properties, but prediction from sequence is probabilistic, not exact, using tools like Chou-Fasman with error rates.

Three-Dimensional Structure (D)
Tertiary (and quaternary) structures result from folding driven by distant interactions, hydrophobicity, and chaperones; while AI like AlphaFold improves predictions, accuracy from sequence alone remains imperfect without experimental validation.

The primary structure of protein from gene sequence stands out as the most direct and accurate derivation in molecular biology. Genes encode the exact amino acid order via the genetic code, forming the foundation of protein structure levels. This concept is crucial for exams like GATE Life Sciences, where understanding what information about protein can be derived most accurately from gene sequence tests core genetics knowledge.

Why Primary Structure Prevails

The gene sequence translates to mRNA codons, each specifying an amino acid in the polypeptide chain—N-terminus to C-terminus. This primary structure of protein is unambiguous, as peptide bonds link amino acids covalently during translation. No gene alone dictates secondary (helices/sheets), tertiary (folds), or quaternary assemblies, which rely on physics and context.

Limitations of Other Structures

• Secondary structure: Predictable via hydrophobicity but not “most accurately” without errors.

• 3D structure: Advanced models predict it, yet experimental methods like X-ray crystallography confirm.

• Function: Emerges from active sites in folded forms, not sequence directly.

For protein primary structure from gene sequence mastery, focus on central dogma: DNA → RNA → protein sequence. This ensures precision in competitive biology prep.