Chapter 17 - From Gene to Protein
RNA polymerase moves in which direction along the DNA?
3' --> 5' along the template strand
A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be
3' AAA-GAA-TAA-CAA 5'.
The genetic code is essentially the same for all organisms. From this, one can logically assume all of the following except
DNA was the first genetic material.
Why might a point mutation in DNA make a difference in the level of protein's activity?
It might substitute an amino acid in the active site.
Which of the following is true for both prokaryotic and eukaryotic gene expression?
RNA polymerase binds to the promoter region to begin transcription.
Each of the following options is a modification of the sentence THECATATETHERAT. Which of the following is analogous to a SINGLE SUBSTITUTION mutation?
THECATARETHERAT
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is
UUU.
In the 1920s Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments, in the 1940s, Charlotte Auerbach discovered that chemicals—she used nitrogen mustards—have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation?
We want to prevent any increase in mutation frequency.
Of the following, which is the most current description of a gene?
a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
When does translation begin in prokaryotic cells?
as soon as transcription has begun
The anticodon of a particular tRNA molecule is
complementary to the corresponding mRNA codon.
A frameshift mutation could result from
either an insertion or a deletion of a base.
Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes
excision of introns.
A mutation in which of the following parts of a gene is likely to be most damaging to a cell?
exon
What are the coding segments of a stretch of eukaryotic DNA called?
exons
What type of bonding is responsible for maintaining the shape of the tRNA molecule?
hydrogen bonding between base pairs
When a tRNA molecule is shown twisted into an L shape, the form represented is
its 3-dimensional shape.
What amino acid sequence will be generated, based on the following mRNA codon sequence? 5' AUG-UCU-UCG-UUA-UCC-UUG 3'
met-ser-ser-leu-ser-leu
What is the sequence of a peptide based on the following mRNA sequence? 5' . . . UUUUCUUAUUGUCUU 3'
phe-ser-tyr-cys-leu
Introns are significant to biological evolution because
their presence allows exons to be shuffled.
A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide?
5' TTT-CCC-AAA-GGG-TTT-CCC
Each of the following options is a modification of the sentence THECATATETHERAT. Which of the following is analogous to a FRAMESHIFT mutation?
THECATATTHERAT
Which point mutation would be most likely to have a catastrophic effect on the functioning of a protein?
a base deletion near the start of a gene
Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?
a base-pair deletion
Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?
a deletion of 2 nucleotides
Sickle-cell disease is probably the result of which kind of mutation?
point
What is the most abundant type of RNA?
rRNA
