(1). using the available technology to synthesize DNA with specific sequences di
ID: 3166159 • Letter: #
Question
(1). using the available technology to synthesize DNA with specific sequences directly, you made a DNA molecule with the complete gene sequence or the human insulin gene, including all introns and exons, and inserted it into an expression vector( including bacterial promoter, Shine - Delgarno sequence, and terminator sequence ) in order to produce insulin in bacteria. However, you efforts failed to produce functional insulin and even the pre-proinsulin was not made by the bacteria. What must you "fix" in your vector or the strategy in order to produce functional insulin?
A). Remove the intron sequences since bacteria cannot carry out splicing.
B). Remove the sequences coding for the first 24 amino acids in the n-terminus since bacteria cannot specifically cut the human protein.
C). Produce the two protein chains( A and B) separately since bacteria also cannot cut the proinsulin protein into the two Chains.
D).Two of the above.
E). All of the above
(2) You have isolated a DNA fragment containing a human genes involved in lung cancer and are working inserting it into a standard plasmid vector used in molecular cloning which has a multiple cloning site in the LacZ gene. After cutting the DNA fragment and the vector with the same restriction enzyme and lingating the cut DNA, you transform bacteria with hopefully the recombinant vector. How do you expect to identify bacteria with recombinant vector?
A). Bacteria with recombinant Victor will be resistant to antibiotic treatment and form blue colonies in the present of X -gal.
B). Bacteria which recombinant Victor will be resistant to antibiotic treatment and form white colonies in the presence of X-gal.
C). Bacteria with recombinant Victor will be sensitive to antibiotics treatment( die) and from White colonies in the presence of X-gal.
D). Bacteria with recombinant Victor will be sensitive to antibiotic treatment (die) and form blue colonies in the presence of X-gal.
E). None of the above.
(3). In your Forward genetic study you have identified two mutants with non-lethal defects in your phenotype of interest. You performed a complementation test to see if the mutations are in the same gene or two different genes but The Offsprings from the test die early on in embryogenesis you conclude then that.... (select the most likely exclamation).
A). the mutations are in the same gene.
B). the mutations in two different genes
C). the mutations must cause frameshifts in order to produce the lethal phenotype.
D). Two of the above.
E). can't tell from the information given
(4). At the end of a forward genetics study, you end up with......
A). A list of candidate genes involved in your phenotype of Interest.
B). A list of phenotypes associated with mutations in your genes of Interest.
C). clones of your genes of Interest.
D). Two of the above
E). All of the above.
Explanation / Answer
1) option E. all of the above.
because bacteria cannot carry out splicing so we have to remove the intron sequences.
bacteria cannot specifically cut the human protein so we have to remove the sequences coding for the first 24 amino acids in the N-terminus.
Produce the two protein chains( A and B) separately since bacteria also cannot cut the proinsulin protein into the two Chains.
2) option B. Bacteria which recombinant Victor will be resistant to antibiotic treatment and form white colonies in the presence of X-gal.
a general plasmid also contains antibiotic resistant gene as a selection marker. when a gene is introduced into the plasmid it will disrupt the beta-gal gene so the product of beta-gal gene will not form and it will not metabolize the X gal substrate hence produce the white colony.
3) option B. the mutation in two different gene.
product of A will convert X--------> Y and product of B will convert Y-------> Z and this product will kill the offspring.
in any case if X--------->Z then offspring will die. but mutation in any gene (A or B) the offspring will survive.
4) option A. A list of candidate genes involved in your phenotype of Interest.
forward genetics - from phenotype to genotype.
reverse genetics- from genotype to phenotype.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.