A variation that does not involve a change in DNA sequence but can be passed from one generation to another is a(n)
epigenetic condition
Which of the following is an example of a recombinant DNA molecule?
A genomic fragment of human DNA ligated to a bacterial plasmid vector
If a single DNA molecule is amplified by PCR, how many DNA molecules will there be after six cycles?
64
A contig is
sets of two or more partially overlapping cloned DNA fragments that together cover an uninterrupted stretch of a genome
Dideoxy bases terminate DNA synthesis during DNA sequencing due to a lack of
3'-OH
Proteins that are able to activate gene expression without binding to the DNA are called
coactivators
Histones appear to have a singular role in the packaging of DNA. The nonhistone proteins in chromatin have which of the following functions?
All of the below choices are correct:
different functions for different tissues, such as tissue-specific transcription factors
activity at different moments in the cell cycle
centromere function activity
Attenuation occurs in the biosynthesis pathway for phenylalanine, therefore the leader sequence for this pathway will be rich in
phenylalanine
Random generation of overlapping insert fragments from large clones for the purpose of sequence analysis is termed
shotgun
Most decisions controlling the amount of gene product synthesized are made during
initiation of transcription.
The gene products encoded by trans-acting elements perform their function by
associating with regulatory sequences distant from the gene from which they were transcribed.
What is the function of the ampr gene in a vector
It is a selectable marker
The enzyme that some organisms use to replicate DNA at the ends of chromosomes is called
telomerase
The __________________________ is the cis-acting DNA sequence that serves as the binding site for RNA polymerase.
promoter
Hypercondensation of heterochromatin results in
transcriptional silencing.
The first level of compaction of DNA consists of
DNA winding around histones to form small nucleosomes
How do bacteria protect their own DNA from the restriction enzymes they produce?
Digestion is blocked by methyl groups added to recognition sequences in their DNA
The ________________ is the repeating structural unit of chromatin, consisting of approximately 200 base pairs of DNA and associated histone proteins.
nucleosome
_________________ are transcription factors that decrease transcriptional activity by associating with specific enhancer elements or activator proteins.
Repressors
Which of the following is not true of enhancer DNA sequences?
They contain the TATA box regulatory element.
In which of the following cases will a Barr body be seen?
both XX and XXY
Which of the following is not involved in RNA interference processes?
RNA polymerase I
DNA regions that are transcriptionally silenced by hypercondensation have often undergone a modification of their cytosine residues termed
methylation
Below are several steps involved in FISH. From the choices available, pick the order of steps that would be successful.
1) Fix chromosomes and denature the DNA.
2) Arrest cells in metaphase.
3) Take a picture using ultraviolet light.
4) Drop cells onto mi
2, 4, 1, 5, 6, 3
Transcription in prokaryotes and eukaryotes is similar in that
both are regulated by attachment of proteins to DNA adjacent to the gene being transcribed.
In tryptophan operon regulation in E. coli, tryptophan acts as a(n)
corepressor
In generating a reporter construct to study gene regulation, the reporter gene introduced replaces
the coding region of the gene being studied
Genomic DNA is isolated from bacteria. After a long digestion with a 6-base cutting enzyme that recognizes the sequence GAATTC, the DNA is not cut. The genome is 4 Mb, so there should be approximately 1,000 sites in the DNA. What is the most likely explan
The bacterium methylated the DNA, because it produces the 6-base cutting enzyme
The components of a chromosome include one long DNA molecule and
proteins
Which of the following is not usually seen when a cell loses telomerase activity?
Many normal somatic cells gain the ability to divide indefinitely
Histones and DNA have a strong attraction for each other because
DNA is negatively charged and histones are positively charged
A transcription factor that increases initiation of transcription by associating with an enhancer element is termed a(n)
activator
RNA polymerase binds to the
promoter
Regions of DNA are most sensitive to DNAase digestion when
they are free of histones
The primary function of basal transcription factors is to
assist in associating RNA polymerase with the promoter element.
A cis-acting DNA sequence that modulates the basal rate of transcription of a gene is termed a(n)
enhancer
Zinc-finger peptide motifs are responsible for what aspect of protein function?
DNA binding
The highest resolution map of a genome can best be generated from
sequence analysis
The most efficient control of eukaryotic gene expression is achieved at the level of
transcription initiation
Many operons for genes in anabolic pathways are not expressed in the presence of the final product of the pathway as, for example, with the arginine biosynthesis pathway. Loss of function mutations in regulatory proteins lead to constitutive expression of
A negative regulatory protein with arginine as the co-repressor
A yeast artificial chromosome (YAC) usually consists of
All of the choices below are correct
A yeast centromere
a yeast origin of replication
telomere sequences
suitable selectable markers
FISH analysis is useful for determining the
chromosomal location of a gene.
The lacZ gene is sometimes included in a cloning vector. What does it encode?
a detectable enzyme that is not produced if the gene is interrupted by an insert
Which of the following types of gene regulation occur in both prokaryotes and eukaryotes? More than one answer may be correct.
negative regulation
positive regulation
Genes encode
both noncoding RNAs and proteins
The location of a gene on the Y chromosome could be identified by
FISH and genomic Southern analysis
16 kb linear DNA is cut with EcoRI and BamHI. The EcoRI digest yields fragments of 2, 6, and 8 kb. The BamHI digest yields fragments of 5 and 11 kb. An EcoRIBamHI double digest yields 2, 3, 5, and 6 kb fragments. If the 3 kb fragment from the double diges
8 kb
Which of the following would be suggested by a DNAse hypersensitive site?
The chromatin is in a more open state than a region without the hypersensitive site.
The chromatin is in an open state and available for transcription.
The figure below shows the products from Sanger sequencing, with the negative end of the gel at the top, and the positive end of the gel at the bottom. What is the sequence of the template DNA strand (5' to 3' left to right)?
Gel reads: TCGCCAG
AGCGGTC
_______ _______ are cis-acting DNA sequences that often function at a distance from the gene they are regulating.
enhancer elements
6-base cutting enzyme should cut every 4kb, on average. Approximately how many sites are in the human genome (for simplicity, use 4 million kb as the size of the human genome)?
1,000,000
DNA sequences that serve as binding sites for proteins regulating transcription and are often found adjacent to a gene are said to be
cis-acting
Choose one or more answers from the list below that best completes the following sentence.
The core histone proteins are _______________________.
H2A
H2B
H3
H4
All of the following are associated with the formation of a functional miRNA except
translation on ribosomes.
Where do restriction enzymes come from, and what is their normal physiological function?
Bacteria produce them to protect against viral invasion
The association of DNA with histones to form chromatin affects transcription by
decreasing basal transcription rates.
Which of the following types of gene regulation occur in prokaryotes only?
attenuation
Which mutation in the ?-globin gene could, in theory, be detected with a genomic clone but not with a cDNA clone?
a promoter mutation that prevents transcription
Epigenetic changes that are inherited from parent to offspring can involve which of the following?
Acetylation of histones
Methylation of histones
Methylation of DNA
methylation of RNA
Proteins that consist of two identical polypeptide subunits are classified as
homodimers
Which vector is appropriate for cloning an insert of about 200 kb?
Yeast Artificial Chromosome (YAC)
_____________ are basal transcription factors that associate with TBP to assist in initiating transcription from eukaryotic class II genes.
TAFs
Which is not true of DNA arrays?
This method is too advanced to be applied at this time
From DNA research, sites of transcription and therefore most of the genes along the length of the chromosome appear to be found in
euchromatin
The DNAase enzyme can be used in assays to identify regions of DNA that are
free of associated proteins
_______________ is used to describe a situation in which a gene's expression pattern is dependent upon the parent from which it was inherited.
Genomic imprinting
If DNA has 5 different bases, a restriction enzyme with a 4-base recognition sequence would cut DNA approximately every
625 bp
In Sanger sequencing, what causes DNA synthesis to terminate at a specific base?
nucleotide triphosphates that lack a hydroxyl
Which of the following types of gene regulation occur in eukaryotes only?
Chromatin compaction
Differential splicing
Which of the following is not considered a distinct type of organization within a genome?
nonfunctional sequences