While DNA Microarrays Can Be Used to Determine Whether or Not

question 13

Multiple Choice

While DNA microarrays can be used to determine whether or not a gene is expressed in a cell, quantitative polymerase chain reaction (qPCR) can be used to specifically quantify the extent of gene expression in cells and tissues. To perform qPCR, mRNA is extracted from cells and reverse transcribed to complementary DNA (cDNA) . Using fluorescent DNA molecules that recognize specific gene sequences and DNA polymerase, copies of the gene sequence of interest are made. After the copies are made, a fluorescent detector measures the intensity of the fluorescent signal, which is proportional to the number of mRNA transcripts in the cell and corresponds to the level of gene expression in the cell.
-Which of the following statements regarding the comparison of DNA microarrays and qPCR is false?

• A) Both methods use fluorescent DNA molecules and cDNA.
• B) Both methods can determine whether a gene has been turned on or not.
• C) Both methods use mRNA extracted from cells.
• D) Both methods can accurately quantify the levels of gene expression in cells.

---

Definitions:

Licensure Exam

A standardized test required in many professions to ensure competence and to officially grant permission to practice in that field.

National Mean

A statistical average that represents typical or average performance or measurements across a nation.

Mean

The average of a set of numbers, calculated by adding them together and dividing by the number of values.

Standard Deviation

A measure of the amount of variation or dispersion of a set of values from the mean.