DNA sequencing: Ordering the stages/Teaching Notes

DNA sequencing - the stages

Pedagogic strategy

This section is to be completed without reference to information about sequencing. Provide each student with a copy of the Activity sheet:DNA_to_data_worksheet.

1. ‘Discuss and do’
Instruct students to work in pairs, to discuss the topic in hand. Each pair needs to complete the task to identify the stages of DNA sequencing process.

2. 'Plenary'
Teacher or student-led review / plenary. There is an answer sheet on the teachers page (http://www.yourgenome.org/downloads/pdf/teachers/info/DNA_to_data_answers.pdf)

Question and Answer routine:

(i) Nominate contributions - from one of the pairs - for matching up the text and diagrams.
(ii) Note students' responses on the whiteboard.
(ii) Check if any other pairs have different matchings.
(iii) Seek reasons for differences in matchings.
(iv) Discuss and come to a class consensus on matching and ordering.
(v) Share answer sheet responses – note these on the whiteboard.
(vi) Compare the class answers with the answer sheet.
(vii) Compare and seek reasons from students for any differences.
(vii) Discuss and agree on a final version.
(viii) If time permits, you could show the DNA sequencing Flash animation (10 minutes, 359kB) at http://www.yourgenome.org/teachers/sequencing.shtml.
(xi) If required, give students time to update their work.

About the animation

Age level: 17-18 yrs (A2)
Topic: Genetics, gene technology, sequencing genomes, HGP

A short 'Flash' animation at http://www.yourgenome.org/teachers/sequencing.shtml details the technology involved in centres such as the Sanger Institute. There is an introduction to DNA and genomes; an overview of which countries were involved in the international Human Genome Project; and a description of the biological principles and techniques involved in sequencing the human genome. The animation demonstrates how the principles of the Sanger sequencing method are derived from the natural process of DNA replication. It also demonstrates how recombinant DNA techniques were used in the Human Genome Project to clone DNA sections for sequencing. The animation can be used to discuss the international collaboration in the Human Genome Project.

You can launch the animation directly by clicking the icon or download the animation to keep locally and use without Internet access. This is a silent Flash animation which requires Adobe Flash.

Notes

Some preliminary lesson or homework preparation on the topic of DNA sequencing is necessary. You could, for example, ask students to note the key details from the DNA Sequencing Flash animation (359kB) http://www.yourgenome.org/teachers/sequencing.shtml

Alternatively you could ask students to note key details of sequencing using the 'Human Genome Project student information sheet' (pdf) which details sequencing by the Human Genome Project at: http://www.yourgenome.org/downloads/pdf/teachers/info/HGP_infosheet.pdf.

The stages of DNA Sequencing on the activity sheet could be mixed-up and used as a sorting exercise.