Frameshift from 2-base deletion misses third amino acid Steps:

• Compare sequences: Both share first 6 bases (TAGTAA), coding for amino acids 1 and 2; diseased lacks 2 bases afterward, causing frameshift from codon 3.
• Normal sequence translates to amino acids 1 (Gly), 2 (Ile), 3 (Ile), 4 (Ser) via listed codons.
• Diseased frameshift alters codons 3 and 4, replacing them with different amino acids.
• Thus, original amino acid 3 is absent in diseased protein.

Why C is correct:

• Frameshift disrupts third codon (AUU/AUC/AUA for Ile), per genetic code where non-multiple-of-3 deletions shift reading frame, omitting original codon 3.

Why the others are wrong:

• A: Glycine (codon 1) precedes deletion, unchanged.
• B: First isoleucine (codon 2) is before frameshift, retained.
• D: Serine (codon 4) is altered but not specifically missing; focus is on disrupted codon 3.

Final answer: C