WITH COMPLETE SOLUTIONS GRADED A++
In somatic cell gene therapy, what type of vector is most commonly used to alter a specific set of an
individual's somatic cells?
a.
Virus
b.
Bacteria
c.
RNA polymerase
d.
Recombinant DNA
ANS: A
In somatic cell gene therapy, a vector is used to carry a normal copy of the mutated gene into the
individual's cells. These vectors are usually viruses, such as retroviruses, lentiviruses, or adenoviruses,
which have been genetically modified so that they contain the normal human gene and cannot make
copies of themselves (otherwise they could cause a viral infection). Bacteria, RNA polymerase, and
recombinant DNA are not used as vectors in somatic cell gene therapy.
,In DNA replication, what does the enzyme DNA polymerase do?
a.
Travel along the single DNA strand, adding the correct nucleotide to the new strand
b.
Move along the double strand of DNA to unwind the nucleotides of the double helix
c.
Hold the double strand apart while the correct nucleotides are added to the strand
d.
Transport the double strand of DNA from the nucleus to the cytoplasm for protein formation
ANS: A
The DNA polymerase enzyme travels along the single DNA strand, adding the correct nucleotides to the
free end of the new strand (see Figure 4-3, B). The correct option is the only one that accurately
describes the process involved in DNA replication using DNA polymerase.
How is transcription best defined?
a.
DNA polymerase binds to the promoter site on ribonucleic acid (RNA).
b.
RNA directs the synthesis of polypeptides for protein synthesis.
c.
,RNA is synthesized from a DNA template.
d.
A base pair substitution results in a mutation of the amino acid sequence.
ANS: C
Transcription is the process by which RNA is synthesized from a DNA template. The correct option is the
only one that accurately defines the term transcription.
What is the purpose of using a Giemsa staining technique on chromosomes?
a.
Permit the mitotic process to be followed and monitored for variations.
b.
Allow for the numbering of chromosomes and the identification of variations.
c.
Identify new somatic cells formed through mitosis and cytokinesis.
d.
Distinguish the sex chromosomes from the homologous chromosomes.
ANS: B
One of the most commonly used stains is Giemsa stain. By using banding techniques, chromosomes can
be unambiguously numbered, and individual variation in chromosome composition can be studied.
Missing or duplicated portions of chromosomes, which often result in serious diseases, also can be
, readily identified. The correct option is the only one that accurately describes the purpose of the Giemsa
staining technique.
An amniocentesis indicates a neural tube defect when an increase in which protein is evident?
a.
Cytochrome P-450
b.
Alpha fetoprotein
c.
DNA polymerase
d.
Embryonic proteins
ANS: B
Other disorders can be detected with this procedure. These include most neural tube defects, which
cause an elevation of alpha fetoprotein in the amniotic fluid, and hundreds of diseases caused by
mutations of single genes. Cytochrome P-450 is useful in helping to formulate drug doses more precisely.
DNA polymerase travels along the single DNA strand, adding the correct nucleotides to the free end of
the new strand during DNA replication. Embryonic proteins are not involved in neural tube defects.
Amniocentesis is recommended for pregnant with what history?
a.