BIOCH330 Lecture Notes - Lecture 17: Polynucleotide Phosphorylase, Reading Frame, Deoxyribonuclease
Get access
Related Documents
Related Questions
Fill in the blank. Elongation during translation does NOT involve ____________.
Question 16 options:
the translation of codons according to the genetic code | |
the formation of bonds catalyzed by the ribosome | |
complementary base pairing between RNA molecules | |
amino acids being linked together in a polypeptide | |
reading the DNA template 3' to 5' |
For a given gene, what establishes the reading frame for translation?
Question 17 options:
the location of the enhancer relative to the gene | |
the first three nucleotides at the 5' end of the mRNA | |
the first three nucleotides at the 3' end of the mRNA | |
the start codon in the mRNA | |
the location of the promoter relative to the gene |
Which of the following is the LEAST likely direct consequence of a substitution mutation?
Question 18 options:
changing the length of a protein coded for by a gene | |
changing one amino acid in a protein | |
creating a stop codon | |
eliminating a start codon | |
changing the length of the DNA molecule containing a gene |
Suppose that the pre-mRNA transcript from a eukaryotic gene is 30,000 nucleotides long, and the gene codes for a sequence of 300 amino acids. What is the best explanation for the relationship between these numbers?
Question 19 options:
only the first 900 nucleotides of the pre-mRNA transcript are translated | |
it takes 100 nucleotides to specify a single amino acid | |
300 of the nucleotides in the transcript are important, and the rest are "junk" | |
only the last 900 nucleotides of the pre-mRNA transcript are translated | |
large portions of pre-mRNA transcripts are cut out during RNA processing |
Suppose an individual is born into a population with a novel mutation. Is the new mutation an evolutionary change, and why?
Question 20 options:
no, because it is not a big enough change to count | |
yes, because new mutations are always adaptive | |
yes, because the appearance of a new genetic variant is a genetic change in a population | |
no, because not enough individuals have the mutation for it to matter | |
no, because most mutations are not adaptive |
Part B
Think about the DNA coding sequence of a gene. If an A were swapped for a T, what kind of mutation could it cause and why?
a) It could cause a frameshift nonsense or frameshift missense mutation because it would change the reading frame of the codon triplet. | ||||||||||||||||||||||||||||
b) It could cause a silent, missense, or nonsense mutation because those are the types that can be caused by a nucleotide-pair substitution like this one. | ||||||||||||||||||||||||||||
c) It could cause a nonsense mutation because the sequence would no longer be the same, so the protein would be shorter and non-functional. | ||||||||||||||||||||||||||||
d) It could cause a silent mutation because A and T are complementary to each other so it is not really a substitution mutation. Part C Why is a frameshift missense mutation more likely to have a severe effect on phenotype than a nucleotide-pair substitution missense mutation in the same protein?
|