An operon is made up of
an operator, a promoter, the genes of that particular enzyme. (All of
the Above)
DNA methylation and histone acetylation are examples of
epigenetic phenomena.
An example of repressible operon will be
tryptphan regulation/trp operon.
Muscle cells differ from nerve cells because they
express different genes.
Which of the following supports the argument that viruses are nonliving?
They are not cellular.
Which of the following is characteristic of the lytic cycle?
A large number of phages are released at a time.
Viruses _____.
use the host cell to copy themselves and make viral proteins
Embryonic lethal mutations result in:
Phenotypes that are never born/hatched.
Which of the following genes map out the basic subdivisions along the
anterior-posterior axis of the Drosophila embryo?
Segmentation genes
The formation of the fertilization membrane requires an increase in
the availability of:
Calcium ions
Gases are exchanged in a mammalian embryo in the:
Chorion
Genomic imprinting, DNA methylation, and histone acetylation are all
examples of:
Epigenetic phenomena
In humans, identical twins are possible because:
Early blastomeres can form a complete embryo if isolated.
From earliest to latest, the overall sequence of early development
proceeds in which of the following sequences?
Acrosomal reaction ? cortical reaction ? synthesis of embryo's DNA
begins ? first cell division
In eukaryotes, general transcription factors:
Bind to other proteins or to a sequence element within the promoter
called the TATA box.
At the time of implantation, the human embryo is called a:
Blastocyst
As an embryo develops, new cells are produced as the result of:
Cell division
Which of the following sets of materials are required by both
eukaryotes and prokaryotes for replication?
Double-stranded DNA, four kinds of dntps, primers, origins
A transcription unit that is 8,000 nucleotides long may use 1,200
nucleotides to make a protein. This is best explained by the fact tha
many noncoding stretches of nucleotides are present in mRNA.
A human zygote undergoes its first cell division:
24 hours after fertilization
The vegetal pole of the zygote differs from the animal pole in that:
The vegetal pole has a higher concentration of yolk.
In a newly fertilized egg, the vitelline layer:
Hardens to form a protective cover.
One hereditary disease in humans, xeroderma pigmentosum (XP), makes
homozygous individuals exceptionally susceptible to UV-induced
mutation damage in the cells of exposed tissue, especially skin.
Without extraordinary avoidance of sunlight exposure, patients soon
succumb to numerous skin cancers. Which of the following best
describes this phenomenon?
Inherited inability to repair UV-induced mutation
During fertilization, the acrosomal contents:
Digest the protective jelly coat on the surface of the egg.
In positive control of several sugar-metabolism-related operons, the
catabolite activator protein (CAP) binds to DNA to stimulate
transcription. What causes an increase in CAP?
Decrease in glucose and increase in camp
Which of the following is a protein produced by a regulatory gene?
Repressor
Contact of a sperm with signal molecules in the coat of an egg causes
the sperm to undergo:
The acrosomal reaction
The product of the bicoid gene in Drosophila
provides essential information about:
The anterior-posterior axis
Steroid hormones produce their effects in cells by _____.
binding to intracellular receptors and promoting transcription of
specific genes
The tryptophan operon is a repressible operon that is:
Turned off whenever tryptophan is added to the growth medium
In animals, embryonic stem cells differ from adult stem cells in that
Embryonic stem cells are totipotent, and adult stem cells are pluripotent
The migratory neural crest cells:
Form neural and non-neural structures in the periphery.
If a Drosophila female has a homozygous mutation for a
maternal effect gene, _____.
all of her offspring will show the mutant phenotype, regardless of
their genotype
The outer-to-inner sequence of tissue layers in a post-gastrulation
vertebrate embryo is:
Ectoderm ? mesoderm ? endoderm
From earliest to latest, the overall sequence of early development
proceeds in which of the following sequences?
Cleavage ? gastrulation ? organogenesis
Which of the following experimental procedures is most likely to
hasten mRNA degradation in a eukaryotic cell?
Removal of the 5' cap
A new DNA strand elongates only in the 5' to 3' direction because
DNA polymerase can only add nucleotides to the free 3' end.
The lactose operon is likely to be transcribed when
The cyclic AMP and lactose levels are both high within the cell
An Okazaki fragment has which of the following arrangements?
5' RNA nucleotides, DNA nucleotides 3'
For a repressible operon to be transcribed, which of the following
must occur?
RNA polymerase must bind to the promoter, and the repressor must be inactive.
Which of the following correctly displays the sequence of
developmental milestones?
Cleavage ? morula ? blastula ? gastrula
Your brother has just purchased a new plastic model airplane. He
places all the parts on the table in approximately the positions in
which they will be located when the model is complete. His actions are
analogous to which process in development?
Pattern formation
Fertilization normally
Reinstates diploidy
Transcription of structural genes in an inducible operon _
starts when the pathway's substrate is present
A human blastomere is
An embryonic cell that is much smaller than the ovum.
Cells move to new positions as an embryo establishes its three germ
tissue layers during:
Gastrulation
Two potential devices that eukaryotic cells use to regulate
transcription are
DNA methylation and histone modification
A student wishes to clone a sequence of DNA of ~200 kb. Which vector
would be appropriate?
A bac
Which of the three types of viruses shown below would you expect to
include glycoproteins?
I and II only
The outer-to-inner sequence of tissue layers in a post-gastrulation
vertebrate embryo is
Ectoderm ? mesoderm ? endoderm.
DNA microarrays have made a huge impact on genomic studies because they
Allow the expression of many or even all of the genes in the genome
to be compared at once.
Which of the following describes the transfer of polypeptide
sequences to a membrane to analyze gene expression?
Western blotting
Which of the following is characteristic of the lytic cycle?
A large number of phages are released at a time.
The product of the bicoid gene in Drosophila
provides essential information about
the anterior-posterior axis.
Which of the following is least associated with the others?
Binary fission
In 1997, Dolly the sheep was cloned. Which of the following processes
was used?
Fusion of an adult cell's nucleus with an enucleated sheep egg,
followed by incubation in a surrogate.
One hereditary disease in humans, called xeroderma pigmentosum (XP),
makes homozygous individuals exceptionally susceptible to UV-induced
mutation damage in the cells of exposed tissue, especially skin.
Without extraordinary avoidance of sunlight exposure, patients soon
succumb to numerous skin cancers. Which of the following best
describes this phenomenon?
Inherited inability to repair UV-induced mutation.
Which of the following best describes the complete sequence of steps
occurring during every cycle of PCR?
1. The primers hybridize to the target DNA.
2. The mixture is heated to a high temperature to denature the
double-stranded target DNA.
3. Fresh DNA polymerase is added.
4. DNA polymerase extends the primers to make a copy of the target DNA.
2, 1, 4
Use Figure 20.1 to answer the following question.
Which enzyme was used to produce the molecule in Figure 20.1?
A restriction enzyme
in eukaryotes, general transcription factors
bind to other proteins or to a sequence element within the promoter
called the TATA box.
Which of the following is true of embryonic stem cells but not of
adult stem cells?
They make up the majority of cells of the tissue from which they are derived.
From earliest to latest, the overall sequence of early development
proceeds in which of the following sequences?
Acrosomal reaction ? cortical reaction ? synthesis of embryo's DNA
begins ? first cell division.
Which of the following correctly displays the sequence of
developmental milestones?
Cleavage ? morula ? blastula ? gastrula.
Viral genomes vary greatly in size and may include from four genes to
several hundred genes. Which of the following viral features is most
apt to correlate with the size of the genome?
Size and shape of the capsid
Most human-infecting viruses are maintained in the human population
only. However, a zoonosis is a disease that is transmitted from other
vertebrates to humans, at least sporadically, without requiring viral
mutation. Which of the following is the best example of a zoonosis?
Rabies
Which of the three types of viruses shown below would you expect to
include a capsid(s)?
all three
Genetically engineered plants:
Include a transgenic rice plant that can help prevent vitamin A deficiency
The host range of a virus is determined by
The proteins on its surface and that of the host
How does a bacterial cell protect its own DNA from restriction enzymes?
By adding methyl groups to adenines and cytosines
The reason for using Taq polymerase for PCR is that
It is heat stable and can withstand the temperature changes of the cycler
Embryonic lethal mutations result in
phenotypes that are never born/hatched.
The first cloned cat, called Carbon Copy, was a calico, but she
looked significantly different from her female parent. Why?
X inactivation in the embryo is random and produces different patterns.
The tryptophan operon is a repressible operon that is
turned off whenever tryptophan is added to the growth medium.
As genetic technology makes testing for a wide variety of genotypes
possible, which of the following is likely to be an increasingly
troublesome issue
The need to legislate for the protection of the privacy of genetic information.
What is the most logical sequence of steps for splicing foreign DNA
into a plasmid and inserting the plasmid into a bacterium?
I. Transform bacteria with a recombinant DNA molecule.
II. Cut the plasmid DNA using restriction enzymes.
III. Extract plasmid DNA from bacterial cells.
IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments.
V. Use ligase to seal plasmid DNA to nonplasmid DNA
III, II, IV, V, I
In a hypothetical situation, the genes for sex pilus construction and
for tetracycline resistance are located together on the same plasmid
within a particular bacterium. If this bacterium readily performs
conjugation involving a copy of this plasmid, then the result should be:
The rapid spread of tetracycline resistance to other bacteria in that habitat.
The segment of DNA shown in Figure 20.2 has restriction sites I and
II, which create restriction fragments A, B, and C.
CAB
Yeast artificial chromosomes contain which of the following elements?
Centromeres, telomeres, and an origin of replication
Which of the following is used to make complementary DNA (cDNA) from RNA
Reverse transcriptase
Which of these statements about prokaryotes is correct?
They divide by binary fission, without mitosis or meiosis.
In the figure, when new viruses are being assembled (IV), what
mediates the assembly?.
Nothing; they self-assemble
Why might a laboratory be using dideoxy nucleotides?
To sequence a DNA fragment
Why do RNA viruses appear to have higher rates of mutation?
Replication of their genomes does not involve proofreading.
Which of the following accounts for someone who has had a
herpesvirus-mediated cold sore or genital sore getting flare-ups for
the rest of his or her life?
Copies of the herpesvirus genome permanently maintained in host nuclei.
Why is it so important to be able to amplify DNA fragments when
studying genes?
A gene may represent only a millionth of the cell's DNA.
The DNA fragments making up a genomic library are generally contained in
BACs
Which of the following statements describes the lysogenic cycle of
lambda (?) phage?
The phage genome replicates along with the host genome.