THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A start anticodon on tRNA
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A start codon on DNA
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A tart codon on mRNA
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A start codon on mRNA
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Detailed explanation-1: -During initiation, the small ribosomal subunit binds to the start of the mRNA sequence. Then a transfer RNA (tRNA) molecule carrying the amino acid methionine binds to what is called the start codon of the mRNA sequence. The start codon in all mRNA molecules has the sequence AUG and codes for methionine.
Detailed explanation-2: -Genetic Code Analogy. After binding to the mRNA, the ribosome begins translation at the start codon, AUG, and then moves down the mRNA transcript one codon (three nucleotides) at a time until it reaches a stop codon.
Detailed explanation-3: -During initiation, a macromolecular complex assembled around the small ribosomal subunit selects the start codon on the mRNA and defines the open reading frame.
Detailed explanation-4: -The steps in translation are: The ribosome binds to mRNA at a specific area. The ribosome starts matching tRNA anticodon sequences to the mRNA codon sequence. Each time a new tRNA comes into the ribosome, the amino acid that it was carrying gets added to the elongating polypeptide chain.