Please help I have no idea how to do this... * Problem Sets.pdf 201 851 × G The
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Please help I have no idea how to do this...
* Problem Sets.pdf 201 851 × G The genes shown in the f × D Microsoft word STUDY × G Search Textbook Solutio x How to take a screensho C Secure https://missouri.instructure.com/courses/10738/files/2101026?module item_id-647025 2018SP BIO_SC 2200 David- General Genetics Files>Problem Sets.pdf SP2018 Problem Sets.pdf Home Download Problem Sets.pdf (587 KB) (C) 14 Modules Grades Tegrity Classes Assignments MyLab and 28 (B-C) 1. The genes shown in the following table are from the Lac operon in E. coli. The symbols, a, b, and c represent the repressor (i) gene, the operator (o) region, and the structural gene (z) for B- galactosidase, although not necessarily in that order. Furthermore, the order in which the symbols are written in the genotypes is not necessarily the actual sequence in the lactose operon. t) or inactivity () of the Inducer absent Inducer present Mastering a b c a b c abc NetTutor a bc a b c a bc a b c Decide which symbol (a, b, c) represents which gene (i, o, z). 2. You are studying control of the degradation of a natural product, designated simply compound X, by a soil bacterium. You know that the enzyme X degradase is coded by a single structural gene designated S, and that the expression of this gene is affected by the presence or absence of X in the medium, as shown in Table 1 (next page). To investigate control of the degradase, you isolate several mutants that show altered patterns of enzyme production. The phenotypes of these mutants Previous Next 9:05 PM O Type here to search 5/9/2018Explanation / Answer
1) c = repressor gene; b = Lac z structural gene and a = Operator region
Take the first genotype - a- b+ c+ --->in this case a is mutant, that result in constitutive expression of beta-galactosidase, this indicates that a can be repressor gene or operator
In the second genotype, a+b+c- -----> in this case c is mutant, resulting in constitutive expression of beta galactosidase, this indicates that 'b' is LacZ gene that encodes for beta galactosidase.
Now see in the diploid a+b+c-/a-b-c+ ----> in this case no beta galactosidase forms in the absence of inducer i.e., inducible expression is seen; and we know that repressor trans activity and operator has cis activity. Inducible expression can only be seen if all the gene are functional and here in one haploid c is mutatnt and in other is functional. So if protein encoded by c has trans activity then only it can bind to operator (as its other genes are mutated) present on the other haploid.
Therefore this indicates that protein encoded by 'c' is trans-acting and is repressor gene and cis acting gene 'a' is operator region