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Released STAAR Biology EOC · 2025 · Item 36 · 1 point

Walkthrough: Biology 2025, Item 36

B.7B · Protein Synthesis · unscored study

A standard mRNA codon chart arranged by first, second, and third base. It shows, for example, that UCU, UCC, UCA, and UCG code for Ser; UGU and UGC code for Cys; UGG codes for Trp; and CGU, CGC, CGA, and CGG code for Arg.
mRNA codon chartOriginal visual from the released STAAR test.

A portion of an mRNA sequence and a codon chart are shown. 5' UCU UGU CGA 3' Based on the codon chart, what sequence of amino acids is produced when this mRNA is translated?

  1. Thr - Asn - Glu
  2. Cys - Phe - Leu
  3. Ser - Cys - Arg
  4. Ser - Trp - Asp

1. Understand the question

Translate three mRNA codons with the codon chart, reading the first, second, and third bases in order.

Try the question on your own first, then reveal one step at a time.

2. Solve it step by step

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Question, artwork, answer key and rationale: Texas Education Agency released STAAR test. Walkthrough steps written by TEKSForge. Studying here does not change your mastery or scores.