Question 1

Where is messenger RNA formed?&#10;A) Mitochondria&#10;B) Golgi organelle&#10;C) Ribosomes&#10;D) Nucleus

Accepted Answer

Messenger RNA is formed in the nucleus during transcription. It is then transported out of the nucleus to the cytoplasm where it binds with ribosomes for translation into proteins. Mitochondria and Golgi organelles have different functions and are not involved in mRNA formation.

Question 2

What is the cell type and tissue of choice for molecular techniques used to detect acquired DNA mutations leading to malignancy?&#10;A) Peripheral blood mature lymphocytes&#10;B) Bone marrow hematopoietic stem cells&#10;C) The malignant tissue&#10;D) Peripheral blood mature neutrophils

Accepted Answer

The malignant tissue would be the best choice as it directly contains the mutated cells responsible for the malignancy. It would also provide a larger sample size compared to peripheral blood or bone marrow.

Question 3

Before molecular methods are performed, the DNA must be:&#10;A) Primed&#10;B) Flanked&#10;C) Elongated&#10;D) Amplified

Accepted Answer

Before molecular methods can be performed, the DNA must be amplified to increase the amount of DNA available for analysis. Amplification can be done through techniques such as PCR (polymerase chain reaction) or other nucleic acid amplification methods. Priming, flanking and elongation are all steps that occur during the amplification process.

Question 4

What is a tumor-suppressing cellular protein that can sense early DNA damage?&#10;A) p53&#10;B) Transfer RNA&#10;C) Apoptosis protein&#10;D) RNA polymerase

Accepted Answer

p53 is a well-known tumor-suppressing protein that can sense early DNA damage and trigger various cellular responses, including apoptosis and cell cycle arrest. Transfer RNA, Apoptosis protein, and RNA polymerase do not play a direct role in sensing DNA damage.

Question 5

Why is the helical configuration of DNA important?&#10;A) Permits purines and pyrimidines to bond&#10;B) Permits transcription of DNA by RNA polymerase&#10;C) Stabilizes the molecular structure&#10;D) Prevents occurrence of protein structural abnormalities (e.g., point mutations, translocations)

Accepted Answer

The helical configuration of DNA plays a crucial role in stabilizing its molecular structure. The double helix shape helps to protect the genetic information coded by the sequence of nucleotides. The stable structure of DNA also ensures that the bases remain properly aligned, preventing errors during replication and transcription.

Question 6

Molecular testing is useful for all of the following except:&#10;A) Evaluating clinical severity of anemia&#10;B) Finding chromosomal translocations in malignancies&#10;C) Detecting inherited disorders&#10;D) Identifying blood pathogens

Accepted Answer

Molecular testing can help find chromosomal translocations in malignancies, detect inherited disorders, and identify blood pathogens, but it is not useful for evaluating the clinical severity of anemia. Other diagnostic tests, such as a complete blood count, are better suited for this purpose.

Question 7

Gel electrophoresis, restriction endonucleases, and hybridization techniques are methods to:&#10;A) Detect DNA amplification&#10;B) Detect DNA extraction&#10;C) Measure concentration of DNA&#10;D) Identify BCR gene in chronic myelogenous leukemia

Accepted Answer

The answer of Gel electrophoresis, restriction endonucleases, and hybridization techniques...

Question 8

Why is a &#34;no DNA&#34; control used when performing molecular tests using the polymerase chain reaction (PCR)?&#10;A) To ensure that the targeted DNA is amplified&#10;B) To ensure that nontargeted DNA is negative&#10;C) To ensure that the targeted DNA containing the mutation is positive&#10;D) To ensure that no DNA cross-contamination of the samples, controls, or reagents occurs

Accepted Answer

The "no DNA" control is used to ensure that there is no DNA cross-contamination of the samples, controls, or reagents that can affect the accuracy of the results. It is important to have a negative control to distinguish between true negatives and false positives. A positive control is also used to ensure that the targeted DNA is amplified and to validate the PCR reaction. However, the "no DNA" control specifically addresses the possibility of contamination during the experimental process. The other options (A, B, and C) are not the main purpose of using a "no DNA" control.

Question 9

DNA has been isolated from appropriate cells and placed in an aqueous buffer. If molecular testing cannot be immediately performed, what should be done?&#10;A) Reprecipitate the DNA using isoproponol alcohol and then store at 4 $\degree$C&#10;B) Reprecipitate the DNA using isoproponol alcohol and then store at -80 $\degree$ C&#10;C) Store prepared DNA at 4 $\degree$ C&#10;D) Store prepared DNA at -80 $\degree$ C

Accepted Answer

Storing DNA at -80°C helps preserve its integrity for long-term storage, preventing degradation and maintaining its suitability for future molecular testing.

Question 10

How does ribonucleic acid (RNA) differ from deoxyribonucleic acid (DNA)?&#10;A) RNA does not contain nucleotides.&#10;B) RNA has uracil-replacing thymine.&#10;C) DNA is found primarily in the cytoplasm, and RNA is in the nucleus.&#10;D) DNA has a messenger, whereas RNA does not.

Accepted Answer

RNA has uracil as one of its nitrogenous bases, whereas DNA has thymine. This is the primary difference between the two nucleic acids.

Question 11

What is the preferred specimen for molecular techniques for diagnosis of inherited mutations?&#10;A) RNA extracted from peripheral mature red cells&#10;B) RNA extracted from fresh serum&#10;C) DNA extracted from peripheral blood white cells&#10;D) DNA extracted from peripheral blood mature red cells

Accepted Answer

The answer of What is the preferred specimen for molecular...

Deck 32: Molecular Diagnostics in the Clinical Laboratory