#Question id: 2867
#Unit 2. Cellular Organization
Deletion in region 3 enhances operon or rate of transcription (in trp operon); Choose an incorrect statement.
#Question id: 2868
#Unit 2. Cellular Organization
Given the following mutants and conditions, predict the expression of the of the lacZ gene (no expression, basal level of expression, or activated level of expression). A mutant of E. coli that has a mutation in the operator of the lac operon that prevents the repressor from binding
|
Glucose |
Lactose |
Expression |
|
+ |
- |
1 |
|
+ |
+ |
2 |
|
- |
- |
3 |
|
- |
+ |
4 |
#Question id: 2869
#Unit 2. Cellular Organization
Galactose imported into the yeast cell is converted to galactose 6-phosphate by a pathway involving six enzymes, whose genes are scattered over three chromosomes. Transcription of these genes is regulated by the combined actions of the proteins Gal4p, Gal80p, and Gal3p,
|
i. GAL3 |
a. Interaction with the Gal80p-Gal4p complex and activates Gal4p. |
|
ii. GAL4 |
b. Recruits SAGA, Mediator, and TFIID to the galactose promoters, leading to DNA polymerase II recruitment and initiation of transcription |
|
iii. GAL80 |
c. Transcriptional inhibitor |
|
d. Transcriptional activator |
#Question id: 2870
#Unit 2. Cellular Organization
In Escherichia coli, the synthesis of tryptophan is controlled by the tryptophan operon that is repressed in the presence of excessive tryptophan. When a mutant strain that has lost the regulatory gene of the tryptophan operon is placed in a medium that contains all nutrients the cells need to grow except tryptophan, which of the following will occur?
#Question id: 2871
#Unit 2. Cellular Organization
With respect to X-chromosome inactivation in females, which, if any, of the following statements is incorrect?
#Question id: 2872
#Unit 2. Cellular Organization
Concerning disorders resulting from unstable expansion of tandem oligonucleotide repeats, which, if any of the following statements is false.
A) The expansions can occur in coding DNA in some cases, and in noncoding DNA in other cases.
B) The repeats are of a variable number of nucleotides (from three to six) in both coding DNA and noncoding DNA.
C) The expansions in noncoding DNA are generally much larger in size than those in coding DNA.
D) The expanded arrays in noncoding DNA always result in loss of function of the host gene or of a neighboring gene.