Which of the following is a likely explanation for the lack of transgene expression in the fifth
cell line?
A) The transgene integrated into a heterochromatic region of the genome.
B) The transgene integrated into a euchromatic region of the genome.
C) The transgene was mutated during the process of integration into the host cell genome.
D) The host cell lacks the enzymes necessary to express the transgene.
E) The transgene integrated into a region of the genome characterized by high histone
acetylation.

The transgene integrated into a heterochromatic region of the genome.

Of the lines that express the transgene, one is transcribed but not translated. Which of the
following is a likely explanation?
A) no promoter
B) no AUG in any frame
C) no compatible ribosome
D) high histone acetylation
E) missing transcription factor

no AUG in any frame

In one set of experiments she succeeded in decreasing methylation of histone tails. Which of
the following results would she most likely see?
A) increased chromatin condensation
B) decreased chromatin condensation
C) activation of histone tails for enzymatic function
D) decreased binding of transcription factors
E) inactivation of the selected genes

decreased chromatin condensation

One of her colleagues suggested she try increased methylation of C nucleotides in a
mammalian system. Which of the following results would she most likely see?
A) increased chromatin condensation
B) decreased chromatin condensation
C) activation of histone tails for enzymatic function
D) decreased binding of transcription factors
E) inactivation of the selected genes

inactivation of the selected genes

In one set of experiments using this procedure in Drosophila, she was readily successful in
increasing phosphorylation of amino acids adjacent to methylated amino acids in histone tails.
Which of the following results would she most likely see?
A) increased chromatin condensation
B) decreased chromatin condensation
C) activation of histone tails for enzymatic function
D) decreased binding of transcription factors
E) inactivation of the selected genes

decreased chromatin condensation

In addition, she finds what other evidence of this single-stranded RNA piece's activity?
A) She can measure the degradation rate of the remaining single strand.
B) She can measure the decrease in the concentration of Dicer.
C) The rate of accumulation of the polypeptide encoded by the target mRNA is reduced.
D) The amount of miRNA is multiplied by its replication.
E) The cell's translation ability is entirely shut down.

The rate of accumulation of the polypeptide encoded by the target mRNA is reduced.

If a particular operon encodes enzymes for making an essential amino acid and is regulated
like the trp operon, then
A) the amino acid inactivates the repressor.
B) the enzymes produced are called inducible enzymes.
C) the repressor is active in the absence of the amino acid.
D) the amino acid acts as a corepressor.
E) the amino acid turns on transcription of the operon.

the amino acid acts as a corepressor.

The functioning of enhancers is an example of
A) transcriptional control of gene expression.
B) a post-transcriptional mechanism to regulate mRNA.
C) the stimulation of translation by initiation factors.
D) post-translational control that activates certain proteins.
E) a eukaryotic equivalent of prokaryotic promoter functioning.

transcriptional control of gene expression.

Which of the following is an example of post-transcriptional control of gene expression?
A) the addition of methyl groups to cytosine bases of DNA
B) the binding of transcription factors to a promoter
C) the removal of introns and alternative splicing of exons
D) the binding of RNA polymerase to transcription factors
E) the folding of DNA to form heterochromatin

the removal of introns and alternative splicing of exons

What would occur if the repressor of an inducible operon were mutated so it could not bind
the operator?
A) irreversible binding of the repressor to the promoter
B) reduced transcription of the operon's genes
C) buildup of a substrate for the pathway controlled by the operon
D) continuous transcription of the operon's genes
E) overproduction of catabolite activator protein (CAP)

continuous transcription of the operon's genes

Which of the following statements about the DNA in one of your brain cells is true?
A) Most of the DNA codes for protein.
B) The majority of genes are likely to be transcribed.
C) Each gene lies immediately adjacent to an enhancer.
D) Many genes are grouped into operon-like clusters.
E) It is the same as the DNA in one of your kidney cells.

It is the same as the DNA in one of your kidney cells.

Which of the following would not be true of cDNA produced using human brain tissue as the
starting material?
A) It could be amplified by the polymerase chain reaction.
B) It would contain sequences representing all the genes in the genome.
C) It was produced from mRNA using reverse transcriptase.
D) It could be used as a probe to detect genes expressed in the brain.
E) It lacks the introns of the human genes.

It would contain sequences representing all the genes in the genome.