DNA replication and gene expression
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Which RNA directly matches an anticodon to an mRNA codon?
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tRNA
A charged tRNA links codon recognition to delivery of an amino acid.
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Why are RNA primers necessary?
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DNA polymerase requires an existing 3-prime OH to extend.
A primer supplies an extendable starting end.
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Which feature makes the usual end-replication problem relevant?
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A linear end with no upstream 3-prime end after primer removal
This prevents ordinary polymerase from filling that terminal gap.
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Coding DNA is 5-prime ATG CCT 3-prime. Which is the RNA?
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5-prime AUG CCU 3-prime
Replace T with U while retaining coding-strand order and direction.
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A DNA coding strand reads 5' ATG GCA TTC 3'. Which is the mRNA made from this gene?
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5' AUG GCA UUC 3'
mRNA has the same sequence as the coding strand, with U in place of T, because it pairs with the template strand.
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What is retained after ordinary splicing?
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Exons joined in the mature RNA
Introns are removed and retained exon regions are linked.
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Which statement correctly relates codon and anticodon?
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A tRNA anticodon pairs complementarily with an mRNA codon.
This connects the message to delivery of the corresponding amino acid.
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Which statements about translation are correct? 1: The ribosome moves along mRNA one codon at a time. 2: Each tRNA can carry any amino acid. 3: Peptide bonds form between amino acids. 4: A stop codon is read by a tRNA carrying no amino acid.
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1 and 3 only
The ribosome moves codon by codon and peptide bonds join amino acids. Each tRNA carries one specific amino acid, and stop codons bind release factors.
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