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 high-throughput molecular biology tool. It consists of a solid surface, such as a glass slide, with thousands of DNA sequences (probes) arranged in an ordered array.

Step 2: Detailed Explanation:
- DNA microarrays primarily measure gene expression levels (mRNA production) for thousands of genes simultaneously. - mRNA is extracted from two cell populations (e.g., cancerous vs. normal), converted to fluorescently labeled cDNA, and hybridized to the microarray. - Fluorescence intensity at each spot reveals genes with increased (upregulated) or decreased (downregulated) activity in one condition compared to another. - This is ideal for studying gene expression changes in diseases like cancer. - Option (B) describes electrophoresis. - Option (C) describes the Polymerase Chain Reaction (PCR). - Option (D) is studied using ribosome profiling or mass spectrometry (proteins), not DNA microarrays.
Step 3: Final Answer:
A DNA microarray's best application is investigating gene expression levels, such as in a cancerous cell. Option (A) is correct.