Use the following model of a eukaryotic transcript to answer the next few questions.
5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3'
1) Which components of the previous molecule will also be found in mRNA in the cytosol?
A) 5' UTR I1 I2 I3 UTR 3'B) 5' E1 E2 E3 E4 3'
C) 5' UTR E1 E2 E3 E4 UTR 3'
D) 5' I1 I2 I3 3'
E) 5' E1 I1 E2 I2 E3 I3 E4 3'
Answer: C
2) When the spliceosome binds to elements of this structure, where can it attach?
A) to the exonsB) to the 5' UTR
C) to the 3' UTR
D) to an adjacent intron and exon
E) to the end of an intron
Answer: E
3) Which of the following is a useful feature of introns for this model?
A) They are translated into small polypeptides.B) They become parts of snRNPs.
C) Each intron has enzymatic properties.
D) Introns allow exon shuffling.
E) Introns protect exon structure.
Answer: D
4) Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I1). What might occur?
A) loss of the gene productB) loss of E1
C) premature stop to the mRNA
D) inclusion of I1 in the mRNA
E) exclusion of E2
Answer: D
5) Suppose that an induced mutation removes most of the 5' end of the 5' UTR. What might result?
A) Removal of the 5' UTR has no effect because the exons are still maintained.B) Removal of the 5' UTR also removes the 5' cap and the mRNA will quickly degrade.
C) The 3' UTR will duplicate and one copy will replace the 5' end.
D) The first exon will not be read because I1 will now serve as the UTR.
E) Removal of the 5' UTR will result in the strand not binding to tRNAs.
Answer: B