Question

a codon is defined as ________
answer
○ a coding strand
○ a sequence of three amino acids in a protein
○ a three - base sequence on mrna
○ a three - base sequence on trna
○ i dont know yet

Explanation:

To determine the correct definition of a codon, we analyze each option:

• "a coding strand": A coding strand is part of DNA, not the definition of a codon. Eliminate this.
• "a sequence of three amino acids in a protein": Codons are related to nucleic acids (mRNA), not amino acid sequences in proteins. Eliminate this.
• "a three - base sequence on mRNA": By definition, a codon is a three - nucleotide (base) sequence on messenger RNA (mRNA) that codes for an amino acid or a stop signal during translation. This matches the definition.
• "a three - base sequence on tRNA": The three - base sequence on tRNA is called an anticodon, which is complementary to a codon on mRNA. Eliminate this.
• "I DON'T KNOW YET" is not a valid answer for the definition.

Answer:

C. a three - base sequence on mRNA