Week 13 Quiz

A  changing part of the active site of the enzyme

B  causing early termination during the elongation cycle of translation.

C  shifting the reading frame for the codons downstream of the mutation

D  preventing formation of the initiation complex during transcription.

A  By transcribing different segments of a single gene, RNA polymerase II can produce different mRNA molecules

B  A single pre-mRNA can be spliced to form different mature mRNAs by including different sets of exons

C  By translating different segments of a single mRNA molecule, ribosomes can produce different proteins

D  The genetic code is degenerate, so a single codon may code for several different amino acids

A  During translation in eukaryotes, some ribosomes remain free in the cytoplasm while others attach to protein channels embedded in the rough ER.

B  Ribosomes are composed of RNA and protein.

C  During translation, an amino acid attached to a tRNA in the A site is transferred to a growing polypeptide attached to a tRNA in the P site.

D  A peptide bond forms between the amino acid attached to a tRNA in the A site and the growing polypeptide attached to a tRNA in the P site.

A  5′ UCCGA 3′

B  5′ TCCGA 3′

C  3′ TCCGA 5′

D  3′ UCCGA 5′

A  In DNA replication the helix is never closed after it is opened by helicase, but once RNA polymerase has finished transcribing a region the double helix closes

B  DNA replication produces a fundamentally different type of molecule than is produced by RNA transcription

C  DNA replication occurs in the nucleus, and RNA transcription occurs in the cytoplasm

D  Synthesis occurs in the 3′ to 5′ direction in DNA replication but in the 5′ to 3′ direction in RNA transcription