• Open Reading Frame (ORF):
• In molecular genetics, an Open Reading Frame (ORF) refers to a continuous stretch of DNA or RNA nucleotides that starts with an initiation codon (typically $5'\text{-AUG-}3'$), followed by a continuous series of nucleotide triplets (codons) that specify the amino acid sequence of a polypeptide, and terminates at a stop codon ($5'\text{-UAA/UAG/UGA-}3'$).
• nalysis:
• (The nucleotides of a gene that make up the codons specifying amino acids): Correct definition.

Correct option: (2) The nucleotides of a gene that make up the codons specifying amino acids.

• Wobble Hypothesis & Inosine: Inosine is a modified purine nucleoside containing the base hypoxanthine, formed by post-transcriptional deamination of adenine in tRNA anticodons.
• Wobble Base Pairing: When present at the wobble position (the first base of the anticodon, $5'$ position), inosine can form stable, non-Watson-Crick hydrogen bonds with three different bases in mRNA codons:
• Uracil (U) (2 hydrogen bonds)
• Cytosine (C) (2 hydrogen bonds)
• Adenine (A) (2 hydrogen bonds)
• It does not pair with Guanine (G) due to severe steric hindrance and electrostatic repulsion between purine ring substituents.

Correct option: (4) U, C, and A,