IB Biology Practical Investigations/Genetics/DNA Microarray Virtual Lab

DNA MICROARRAY
TEACHING OBJECTIVE:


 * Observe a high-tech lab technique in action in this excellent Flash application, whilst learning how cancer cells and healthy cells express genes differently.

TASK OUTCOMES:
 * By the end of this activity, students will be able to:
 * describe the function and origin of the DNA Microarray
 * perform a simple virtual lab to compare the microarrays of healthy cells and cancer cells
 * illustrate how cancer cells express genes differently to healthy cells
 * Explain the function of reverse transcriptase in a biotechnological application

TIME REQUIRED:
 * 20-30 minutes

INTRODUCTION:

In this excellent Flash application from learn.genetics (Utah university), students are introduced to the 'new' science of genomics and are shown how a DNA microarray works. Thay are then instructed to carry out a virtual microarray that illustrates the genetic difference between a healthy skin cell and a melanoma cell. Students can use this task as a means to learn about genomics and the use of reverse transcriptase and to revise protein synthesis.

MATERIALS AND EQUIPMENT:


 * DNA Microarray virtual lab from


 * Teacher-set questions



OTHER RESOURCES NEEDED:


 * Individual access to computers is beneficial


 * Internet connection


 * Macromedia Flah Player (latest version)

INSTRUCTIONS:


 * Send students to the learn.genetics homepage and ask them to find the DNA microarray in the virtual labs section.


 * Students complete the microarray learning exercise individually.

SAMPLE QUESTIONS


 * What is the main difference between Genetics and Genomics? (scale of work and time consumption)


 * Which of the following statements are true?


 * An erythrocyte and a skin cell in the same body contain the same DNA. (T)


 * Different genes are expressed in different cell types within the same organism. (T)


 * Gene expression can be observed as production of tRNA. (F - mRNA)


 * Each spot on a Microarray represents one gene. (T)


 * A cancer cell will express most of the same genes as a healthy cell. (T)


 * Reverse transcriptase makes a new strand of RNA. (F - it makes copy DNA (cDNA))


 * Produce a flow-chart of the process of a microarray


 * If a gene is not expressed, what would you expect to see on a microarray scan?
 * green marker
 * red marker
 * yellow marker
 * no marker      (T)

IDEAS FOR FURTHER INVESTIGATION


 * learn.genetics has a number of excellent Flash applications and podcasts suitable for DP Biology.

SOURCES AND REFERENCES:


 * wikipedia: DNA Microarray


 * learn.genetics at the University of Utah