Transcript B1510_module4-6_DNA_to_protein_questions

Gene Expression: from DNA to protein
to phenotype
• How is DNA transcribed to RNA?
• How is mRNA translated to protein?
• How do alterations in DNA lead to
alterations in phenotype?
Q: This figure shows gene expression in what type
of cell? (polyribosome = complex of ribosomes +
mRNA + polypeptide chains being synthesized)
A) Prokaryotic cell
B) Eukaryotic cell
C) Could be either prokaryotic or eukaryotic
Q: What is the direction of transcription in
this figure?
A) left to right 
B) right to left 
C) not enough information to determine
Q: The sequence below is a portion of the
template strand of DNA. What is the RNA
sequence transcribed from this template?
5’-AAGCTGAGCGAT-3’
A) 5’-AAGCUGAGCGAU-3’
B) 5’-TTCGACTCGCTA-3’
C) 5’-AUCGCUCAGCUU-3’
D) 5’-UUCGACUCGCUA-3’
E) 5’-ATCGCTCAGCTT-3’
Q: The sequence below is the 5’ end of an mRNA;
what are the first four amino acids of the
polypeptide that will be translated from it?
5’-UACGAGUAUGCCAGGUCAG….
A) N-TyrGluTyrAla….
B) N-AspTrpThrVal….
C) N-MetProGlyGln….
D) C-MetProGlyGln….
E)
N-TyrThrArgGlu….
Q: The sequence below is the 5’ end of an mRNA;
what are the first three amino acids of the
polypeptide that will be translated from it?
5’-AUAUGAGUAUGCCAGGUC….
A) C-MetSerMet….
B) N-MetSerMet….
C) N-MetProGly….
D) N-IleTyrMet….
E)
N-Ile(Stop)….
Q: The sickle cell mutation changes a glutamic acid
(glu) to valine (val). What is the specific base
change in the DNA?
A)
B)
C)
D)
E)
A→T
A→U
A→G
G→A
G→C
Which type of mutation is most likely to
render a protein non-functional?
A. A mis-sense mutation
B. A nonsense mutation near the 3’ end of the
coding region
C. A single nucleotide deletion near the 5’
end of the coding region
D. A single nucleotide insertion near the 3’
end of the coding region
E. A 3-nucleotide deletion in the middle of
the coding sequence.
Questions for discussion:
• What is a mutation?
• Do healthy people have “mutations” in their
DNA?
• Do all “mutations” have bad consequences?
Genomics is now, and it’s personal!
• Resnick TED talk
• 23 and Me SNP (single nucleotide
polymorphism) profiling
http://www.mun.ca/biology/scarr/DNA_Chips.html
Breast cancer
(BRCA1,2)
What do these 3 SNPs:
185delAG, 5382insC, and
6174delT have in common?
Lactose intolerance
Based on this information,
what is the mode of
inheritance of lactose
intolerance?
Which of these should concern me most?
Closer look at prostate cancer
Overall heritability estimate: 42-57%
Asian ancestry: 16.4%
Average risk: 11.2%
European ancestry: 15.3%
Average risk: 17.8%