Frameshift mutation alters protein sequence and function Steps:

• Compare sequences: Normal CCG-TAT-TGC-GAA-TAT; mutated CCG-TAT-TGT-CGA-ATA-AT shows shifted grouping after second codon, indicating insertion/deletion causing frameshift.
• Determine normal mRNA codons (U for T): CCG (Pro), TAT (Tyr), TGC (Cys), GAA (Glu), TAT (Tyr).
• Determine mutated mRNA codons: CCG (Pro), TAT (Tyr), TGT (Cys), CGA (Arg), ATA (Ile), incomplete AT.
• Conclude frameshift changes amino acids from third codon (Cys-Glu-Tyr to Cys-Arg-Ile) and likely disrupts protein function.

Why D is correct:

• Frameshift mutations shift the reading frame per genetic code, producing altered amino acid sequences (3) and typically non-functional proteins (4) due to incorrect folding or truncation.

Why the others are wrong:

• A: Includes 1, but no stop codons (UAG, UAA, UGA) appear in mutated mRNA.
• B: Includes 1, but no stop codons are introduced.
• C: Excludes 4, but frameshift extensively alters the protein, making it non-functional.

Final answer: D