Inducible enzymes
are produced when a small molecule inactivates the repressor protein
In E. Coli, trptophan switches off the trp operon by
binding to the repressor and increasing the latter's affinity for the operator
In the control of gene expression in bacteria, a regulatory gene
all of the above
A mutation that renders nonfunctional the product of a regulatory gene for a repressible operon would result in
continuous transcription of the genes of the operon
DNA methylation of cytosine residues
may be a mechanism of epigenic inheritance when methylation patterns are repeated in daughter cells
which of the following is not true of enhancers?
each gene may have several enhancers, and each enhancer may be associated with and regulate several genes
Which of the following is NOT an example of the control of gene expression after transcription?
rRNA genes amplified in multiple copes in the genome
A eukaryotic gene typically has all of the following associated with it except
an operator
proteasomes are
enormous protein complexes that degrade proteins marked with ubiquitin
which of the following is not descriptive of small ncRNAs
they are often found n "transcription factories
which of the following descriptions is NOT part of the process by which miRNA regulates gene expression
if the miRNA
pattern formation in animals is based on
positional info
how is the coordinated transcription of genes involved in the same pathway regulated
the genes have the same
which of the following might a proto-oncogene code for
receptor protein for growth factors
a gene can develop into an oncogene when
any of the above occur
a tumor-suppressor gene could cause the onset of cancer if
both a and d have occured
apoptosis is
a cell suicide
which of the following would most likely account for a family history of colorectal cancer?
inheritance of one mutated allele
the role of a metabolite that controls a repressible operon is to
bind to the repressor protein and activate it
a lack of which molecule would result in the cell's inability to "turn off" genes?
ubiquitin
Which of the following, when taken up by the cell, binds to the repressor so that the repressor no longer binds to the operator
inducer
the lactose operon is likely to be transcribed when
the cyclic AMP and lactose levels are both high within the cell
In response to chemical signals, prokaryotes can do which of the following?
alter the level of production of various enzymes
Which of the following mechanisms is (are) used to coordinate the expression of multiple, related genes in eukaryotic cells?
a specific combination of control elements in each gene's enhancer coordinates the simultaneous activation of the genes
genomic imprinting, DNA methylation, and histone amplification are all examples of
epigenetic phenomena
when DNA is compacted by histones...
methylation and phosphorylation of histone tails
two potential devices that eukaryotic cells use to regulate transcription are
DNA methylation and histone modification
steroid hormones produce their effects in cells by
binding to intracellular receptors and promoting transcription of specific genes
gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following?
eukaryotic exons may be spliced in alternative patters
which of the following experimental procedures is most likely to hasten mRNA degradation in a eukaryotic cell?
removal of the 5' cap
which of the following is most likely to have a small protein called ubiquitin attached to it?
a cyclin that usually acts in G1, now that the cell is in G2
The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called
RNA interference
embryonic lethal mutations result in
phenotypes that are never born/hatched
mutations in which of the following genes lead to transformations in the identity of entire body parts?
homeotic genes
which of the following describes proto-oncogenes
they can code for proteins associated with cell growth
which of the following is characteristic of the product of the p53 gene?
it is an activator for other genes
tumor-suppressor genes
can encode proteins that promote DNA repair or cell-cell adhesion
if she moves the repressor gene
the lac operon will function normally
if she moves the operator
the lac operon will be expressed continuously
in one set of experiments
increased chromatin condensation