MMSC490 UPPDATED PAST PAPERS QUESTIONS AND
SOLUTIONS GUARANTEE A+
✔✔The signal for the addition of a poly-A tail to pre-mRNA is
a. UUUUUUU.
b. TTTTTTTT.
c. AAUAAA.
d. GCGCUGC. - ✔✔c. AAUAAA.
✔✔During splicing, pre-mRNAs go through an intermediate stage when they are
shaped like
a. a lariat.
b. a circle.
c. the Greek letter theta
d. a cross. - ✔✔a. a lariat.
✔✔The RNA components of the spliceosome are five different
a. small cytoplasmic RNAs.
b. small nuclear RNAs.
c. microRNAs.
d. siRNAs. - ✔✔a. small nuclear RNAs.
✔✔The form of apolipoprotein B (Apo-B) produced by the intestine is shorter than the
Apo-B produced by the liver. The intestine produces a smaller protein by
a. proteolytic cleavage of the forming polypeptide chain.
b. shortening of the mRNA from the 5' end after transcription.
c. shortening the mRNA from the 3' end after translation.
d. including fewer exons in the mRNA by alternative splicing. - ✔✔b. shortening of the
mRNA from the 5' end after transcription.
✔✔Spliced mRNAs have protective mechanisms, but introns are rapidly degraded in the
a. nucleus.
b. cytoplasm.
c. lysosomes.
d. nucleoli. - ✔✔a. nucleus.
✔✔E. coli contains about _______ different tRNAs that code for _______ different
amino acids.
a. 62; 40
b. 62; 20
c. 50; 20
d. 40; 20 - ✔✔d. 40; 20
, ✔✔The capacity for some tRNAs to recognize more than one codon in mRNA is
explained by a phenomenon called
a. redundancy.
b. wobble.
c. a reading frameshift.
d. degeneracy. - ✔✔b. wobble.
✔✔Translation always occurs on which of the following structures?
a. Ribosomes
b. Endoplasmic reticulum
c. Nuclear envelope
d. Mitochondria - ✔✔a. Ribosomes
✔✔The formation of peptide bonds is catalyzed by which portion of the bacterial
ribosome?
a. Proteins of the small subunit
b. 16S rRNA
c. Proteins of the large subunit
d. 23S rRNA - ✔✔d. 23S rRNA
✔✔In translation, mRNAs are read in the _______ direction, and polypeptide chains are
synthesized from the _______ends.
a. 5ʹ to 3ʹ; carboxyl to the amino
b. 5ʹ to 3ʹ; amino to the carboxyl
c. 3ʹ to 5ʹ; carboxyl to the amino
d. 3ʹ to 5ʹ; amino to the carboxyl - ✔✔b. 5ʹ to 3ʹ; amino to the carboxyl
✔✔During translation, the codons on the mRNA are recognized by complementary base
pairing to the anticodon on the
a. ribosome.
b. transfer RNA.
c. small cytoplasmic RNA.
d. aminoacyl tRNA synthetase. - ✔✔b. transfer RNA.
✔✔The factor that escorts the amionacyl tRNA to the eukaryotic ribosome and then
releases it with GTP hydrolysis following the correct codon-anticodon base pairing is
a. eIF-1.
b. eRF-1.
c. eIF-2.
d. eEF-1α. - ✔✔d. eEF-1α.
✔✔The first amino acid that initiates the eukaryotic polypeptide is
a. any amino acid.
b. glutamine.
SOLUTIONS GUARANTEE A+
✔✔The signal for the addition of a poly-A tail to pre-mRNA is
a. UUUUUUU.
b. TTTTTTTT.
c. AAUAAA.
d. GCGCUGC. - ✔✔c. AAUAAA.
✔✔During splicing, pre-mRNAs go through an intermediate stage when they are
shaped like
a. a lariat.
b. a circle.
c. the Greek letter theta
d. a cross. - ✔✔a. a lariat.
✔✔The RNA components of the spliceosome are five different
a. small cytoplasmic RNAs.
b. small nuclear RNAs.
c. microRNAs.
d. siRNAs. - ✔✔a. small nuclear RNAs.
✔✔The form of apolipoprotein B (Apo-B) produced by the intestine is shorter than the
Apo-B produced by the liver. The intestine produces a smaller protein by
a. proteolytic cleavage of the forming polypeptide chain.
b. shortening of the mRNA from the 5' end after transcription.
c. shortening the mRNA from the 3' end after translation.
d. including fewer exons in the mRNA by alternative splicing. - ✔✔b. shortening of the
mRNA from the 5' end after transcription.
✔✔Spliced mRNAs have protective mechanisms, but introns are rapidly degraded in the
a. nucleus.
b. cytoplasm.
c. lysosomes.
d. nucleoli. - ✔✔a. nucleus.
✔✔E. coli contains about _______ different tRNAs that code for _______ different
amino acids.
a. 62; 40
b. 62; 20
c. 50; 20
d. 40; 20 - ✔✔d. 40; 20
, ✔✔The capacity for some tRNAs to recognize more than one codon in mRNA is
explained by a phenomenon called
a. redundancy.
b. wobble.
c. a reading frameshift.
d. degeneracy. - ✔✔b. wobble.
✔✔Translation always occurs on which of the following structures?
a. Ribosomes
b. Endoplasmic reticulum
c. Nuclear envelope
d. Mitochondria - ✔✔a. Ribosomes
✔✔The formation of peptide bonds is catalyzed by which portion of the bacterial
ribosome?
a. Proteins of the small subunit
b. 16S rRNA
c. Proteins of the large subunit
d. 23S rRNA - ✔✔d. 23S rRNA
✔✔In translation, mRNAs are read in the _______ direction, and polypeptide chains are
synthesized from the _______ends.
a. 5ʹ to 3ʹ; carboxyl to the amino
b. 5ʹ to 3ʹ; amino to the carboxyl
c. 3ʹ to 5ʹ; carboxyl to the amino
d. 3ʹ to 5ʹ; amino to the carboxyl - ✔✔b. 5ʹ to 3ʹ; amino to the carboxyl
✔✔During translation, the codons on the mRNA are recognized by complementary base
pairing to the anticodon on the
a. ribosome.
b. transfer RNA.
c. small cytoplasmic RNA.
d. aminoacyl tRNA synthetase. - ✔✔b. transfer RNA.
✔✔The factor that escorts the amionacyl tRNA to the eukaryotic ribosome and then
releases it with GTP hydrolysis following the correct codon-anticodon base pairing is
a. eIF-1.
b. eRF-1.
c. eIF-2.
d. eEF-1α. - ✔✔d. eEF-1α.
✔✔The first amino acid that initiates the eukaryotic polypeptide is
a. any amino acid.
b. glutamine.
