Practice Test 3
The oocytes used in the research study were taken from newborns. The oocytes used in the
research study in the passage were:
A. haploid cells arrested in prophase I.
B. diploid cells arrested in prophase I.
C. diploid cells arrested in metaphase I.
D. haploid cells arrested in anaphase II. - ANS B.
The cells would be in the period of arrest between the onset of oogenesis in the fetal stage and
the onset of the menstrual cycle, when one cell per month will move forward with meiosis I.
Since these cells have not completed meiosis I yet, they must still be diploids. Primary oocytes
are arrested in prophase I.
What is Synapsis, in respect to cell division? - ANS An important role in bringing together
homologous chromosomes during meiosis I so that crossing over can occur
The melting temperature of the 15-mer oligonucleotide 5'-GACTGCGGTTTTAAC-3' is 42 °C.
Which of the following oligonucleotides would be found primarily in a random coil state at 42 °C?
What would we be looking for? - ANS The correct answer must be an oligonucleotide with a
melting temperature with a lower melting temperature in order to be primarily in the random coil
state at 42°C. In order to have a lower melting temperature, the oligonucleotide must contain
fewer GC nucleotides than the given oligonucleotide
A Patient develops hypersecreting tumors of the parathyroid glands and pituitary gland. Which
of the following is likely to be observed in a patient with MEN-1?
II Hypercalcemia
III Hypocalcemia - ANS II
A Patient develops hypersecreting parathyroid tumors. Increased parathyroid hormone would
increase calcium levels
Secretion of aldosterone has all of the following effects?
1. Decreased loss of Na + in urine.
2. Increased in extracellular fluid volume.
3. Decrease in arterial pressure.
4. Decrease in urine volume. - ANS 1,2,4
, Aldosterone causes increased sodium reabsorption, and because of the rise in systemic Na+,
there will be decreased water loss, increased extracellular fluid volume, and increased blood
pressure.
It will not cause a decrease in blood pressure
PDC deficiency is a rare genetic disease. In PDC deficiency, the pyruvate cannot be converted
to acetyl-CoA. Which of the following conditions would be expected in patients with the disease?
A. Metabolic alkalosis
B. Lactic acidosis
C. Hyperglycemia
D. Hypolipidemia - ANS B.
The cells can only undergo glycolysis and anaerobic respiration. The end product of anaerobic
respiration in humans is lactic acid. Thus, patients with PDC deficiency have lactic acidosis
What is an intercalating agent, in respect to DNA modifications? - ANS It inserts itself between
base pairs in DNA.
Which of the following would be the most effective method to determine if transcription of a gene
had been silenced?
A. DNA fingerprinting
B. ELISA
C. RT-PCR
D. DNA sequencing - ANS C.
RT-PCR uses reverse transcriptase to make cDNA from mRNA. The cDNA can then amplified,
and then tested for. This is the only method listed that can be used to test for the presence of
mRNA and determine if transcription of the gene is occurring or not.
Most biological unsaturated fatty acids are cis and contain non-conjugated double bonds.
Because of this, additional steps are required in β-oxidation. These most likely include:
A. Changing a single double bond to trans via a reductase enzyme in the mitochondrial matrix.
B. Combining two double bonds via a reductase enzyme (which uses NADPH as a reducing
agent), then changing the resultant cis double bond to trans via an isomerase enzyme. - ANS
B.
Monounsaturated fatty acids require an isomerase enzyme to move the double bond during β
-oxidation. Polyunsaturated fatty acids require both an isomerase and a reductase enzyme to
complete β -oxidation; this also requires the reducing agent NADPH
Muscle fibers are composed of small contractile units called sarcomeres. During contraction,
which of the following occurs within a sarcomere?
The oocytes used in the research study were taken from newborns. The oocytes used in the
research study in the passage were:
A. haploid cells arrested in prophase I.
B. diploid cells arrested in prophase I.
C. diploid cells arrested in metaphase I.
D. haploid cells arrested in anaphase II. - ANS B.
The cells would be in the period of arrest between the onset of oogenesis in the fetal stage and
the onset of the menstrual cycle, when one cell per month will move forward with meiosis I.
Since these cells have not completed meiosis I yet, they must still be diploids. Primary oocytes
are arrested in prophase I.
What is Synapsis, in respect to cell division? - ANS An important role in bringing together
homologous chromosomes during meiosis I so that crossing over can occur
The melting temperature of the 15-mer oligonucleotide 5'-GACTGCGGTTTTAAC-3' is 42 °C.
Which of the following oligonucleotides would be found primarily in a random coil state at 42 °C?
What would we be looking for? - ANS The correct answer must be an oligonucleotide with a
melting temperature with a lower melting temperature in order to be primarily in the random coil
state at 42°C. In order to have a lower melting temperature, the oligonucleotide must contain
fewer GC nucleotides than the given oligonucleotide
A Patient develops hypersecreting tumors of the parathyroid glands and pituitary gland. Which
of the following is likely to be observed in a patient with MEN-1?
II Hypercalcemia
III Hypocalcemia - ANS II
A Patient develops hypersecreting parathyroid tumors. Increased parathyroid hormone would
increase calcium levels
Secretion of aldosterone has all of the following effects?
1. Decreased loss of Na + in urine.
2. Increased in extracellular fluid volume.
3. Decrease in arterial pressure.
4. Decrease in urine volume. - ANS 1,2,4
, Aldosterone causes increased sodium reabsorption, and because of the rise in systemic Na+,
there will be decreased water loss, increased extracellular fluid volume, and increased blood
pressure.
It will not cause a decrease in blood pressure
PDC deficiency is a rare genetic disease. In PDC deficiency, the pyruvate cannot be converted
to acetyl-CoA. Which of the following conditions would be expected in patients with the disease?
A. Metabolic alkalosis
B. Lactic acidosis
C. Hyperglycemia
D. Hypolipidemia - ANS B.
The cells can only undergo glycolysis and anaerobic respiration. The end product of anaerobic
respiration in humans is lactic acid. Thus, patients with PDC deficiency have lactic acidosis
What is an intercalating agent, in respect to DNA modifications? - ANS It inserts itself between
base pairs in DNA.
Which of the following would be the most effective method to determine if transcription of a gene
had been silenced?
A. DNA fingerprinting
B. ELISA
C. RT-PCR
D. DNA sequencing - ANS C.
RT-PCR uses reverse transcriptase to make cDNA from mRNA. The cDNA can then amplified,
and then tested for. This is the only method listed that can be used to test for the presence of
mRNA and determine if transcription of the gene is occurring or not.
Most biological unsaturated fatty acids are cis and contain non-conjugated double bonds.
Because of this, additional steps are required in β-oxidation. These most likely include:
A. Changing a single double bond to trans via a reductase enzyme in the mitochondrial matrix.
B. Combining two double bonds via a reductase enzyme (which uses NADPH as a reducing
agent), then changing the resultant cis double bond to trans via an isomerase enzyme. - ANS
B.
Monounsaturated fatty acids require an isomerase enzyme to move the double bond during β
-oxidation. Polyunsaturated fatty acids require both an isomerase and a reductase enzyme to
complete β -oxidation; this also requires the reducing agent NADPH
Muscle fibers are composed of small contractile units called sarcomeres. During contraction,
which of the following occurs within a sarcomere?
