Last modified on 9 July 2009, at 22:56

IB Biology Practical Investigations/Genetics/DNA Microarray Virtual Lab

DNA MICROARRAYEdit

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 [1]
  • 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 excercise 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: