Question

Which one of the following best describes the application of DNA microarray?

• A. To investigate the level of gene expression in a cancerous cell
• B. To separate small biomolecules based on their charge.
• C. To amplify a DNA sequence.
• D. To study the protein synthesis in a cell.

Hint:

Associate "microarray" with a massive-scale analysis of gene activity. It gives a snapshot of which genes are "on" or "off" in a cell at a specific moment, making it perfect for comparing different cell states like healthy vs. diseased.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
A DNA microarray is a powerful molecular biology tool used for high-throughput analysis. It consists of a solid surface (like a glass slide) onto which thousands of different DNA sequences (probes) are spotted in an ordered array.

Step 2: Detailed Explanation:
- The primary application of DNA microarrays is to measure gene expression levels (i.e., the amount of mRNA produced from each gene) for thousands of genes simultaneously. - To do this, mRNA is extracted from two different cell populations (e.g., cancerous vs. normal cells), converted to fluorescently labeled complementary DNA (cDNA), and then hybridized to the microarray. - By analyzing the fluorescence intensity at each spot on the array, researchers can determine which genes are more active (upregulated) or less active (downregulated) in one condition compared to another. - This makes it an ideal tool for investigating the changes in gene expression that occur in diseases like cancer. - Option (B) describes electrophoresis. - Option (C) describes the Polymerase Chain Reaction (PCR). - Option (D) would typically be studied using techniques like ribosome profiling or mass spectrometry to look at proteins, not DNA microarrays.
Step 3: Final Answer:
The best description of a DNA microarray's application is to investigate the level of gene expression, for example, in a cancerous cell. Therefore, option (A) is correct.