Download Read each question and type the answers on another sheet of paper

BIOL 3201 Genetics
Problem Set/ Prokaryotic Regulation
Directions: Read each question and type the answers on another sheet
of paper. Be sure to double space answers and use 12 font size. I will
not accept hand written assignments. You may work in groups of up to 4
students. Place all names on the assignment. This is worth 100 points
and is due on Thursday, July 10, 2014 at 1:00 pm EST. Any assignment
received after 1:00 pm will have 30 points deducted from the final score.
1.
Compare the characteristics of constitutive genes (or housekeeping
genes) and regulated genes.
2.
How could one determine experimentally where a given gene is
located on the spectrum between constitutive and regulated genes?
3.
What distinguishes effectors, inducers, and transcriptional regulatory
proteins from each other?
Provide an example of each.
4.
Draw the organization of the lac operon, labeling the genes and the
5.
Illustrate how catabolite repression (the glucose effect) modulates lac
gene products where applicable.
operon gene expression. Label all molecules involved and the
consequences of the molecular interactions that occur.
6.
A mutant strain of E. coli is found that produces both -galactosidase
and Lactose Permease constitutively (that is, whether lactose is present
or not).
(a)
What are two possible genotypes for this mutant?
(b)
galactosidase at any time but produces Lactose Permease if
lactose is present in the medium.
What is the genotype of this
BIOL 3201 Genetics
Problem Set/ Prokaryotic Regulation
mutant? Be sure to include all four appropriate genes in your
genotype. (ie. LacY should be one of your genes you include)
(c)
A partial diploid is created from the mutants in parts (a) and
(b): When lactose is absent, neither enzyme is made, and when
lactose is present, both enzymes are made.
What is the
genotype of the mutant in part (a)?
7.
Coupling of transcription and translation occurs in prokaryotes and not
in eukaryotes.
8.
Suggest a reason why?
Complete the following table to indicate whether -galactosidase and
lac permease is expressed and, if expressed, whether its expression is
constitutive or inducible.
Enter “A” (absent), “C” (constitutive, either high
or low) or “I” (inducible) in the table.
Genotype
Expression of lac Z
Expression of lac Y
F’
I-P+OCZ+Y-
I- P+O+Z-Y+
1
______________
_______________
F’
I-P+O+Z+Y-
I+ P+OCZ-Y+
_______________
F’
I+P+OCZ+Y-
2
______________
BIOL 3201 Genetics
Problem Set/ Prokaryotic Regulation
I+ P+O+Z-Y-
3
______________
_______________
F’
I+P+OCZ+Y-
I- P+O+Z-Y+
4
______________
5
______________
_______________
F’
ISP-O+Z-Y+
I- P+O+Z+Y-
_______________