Present your answers in complete sentences No need to rewrit

Present your answers in complete sentences. No need to rewrite the questions. Instead, to answer question 1, you can write, “In the virtual lab experiment, DNA microarrays were used to bla..bla…”.

Part II. Go through the DNA Microarray Virtual Lab at:

http://learn.genetics.utah.edu/content/labs/microarray/

Explore the page. Click on the microarray to begin. For most of the questions below, click on “Chapter 3: The experiment”.

3.In this particular experiment, what was the objective of the DNA microarray experiment?

4.In part 3 (isolate mRNA), how were mRNAs separated from tRNAs and rRNAs?   What were on the beads?   What unique property of mRNAs enabled its separation from tRNAs and rRNAs?

5.In part 4 (make labeled DNA copy), briefly describe how labeled cDNAs were generated. Practice using technical terms that you’ve encountered in your professor’s highly informative lectures. Describe the primers and enzymes that were used. Explain the reason for the choice of primer/s. Explain what the “special enzyme” does.

6.Parts 5 and 6. What do the colors red, yellow, and green represent? What do the dark spots mean?

7.Part 7. If you’re a researcher developing a drug to shut off genes that are expressed mostly in cancer cells, will you try to turn off genes that showed up green, red, or yellow?

8.Give two reasons or examples as to why DNA microarray experiments don’t always identify all genes that have “gone bad”. Answers are mentioned in the interactive.

Solution

Objective of the DNA array expriment:

In order to diagnose cancer, one could compare the appearance of cancerous cells with the healthy cells. But cancer cells don\'t always look so different from healthy cells. The experiment is based on the ssumption that cancer is basically a disease caused due to genes that have stopped working properly, thereby causing the cell growth to spin out of control, leading to tumor formation and cancer. Different kinds of cancer are caused by different sets of genes.

The objective of the gene is to know which of the genes in cancer cells are working abnormally so as to diagnose cancer better.