"[These webpages] give a clear explanation on how the polymerase chain reaction works and why it is useful."
This animation has five sections. The animation will stop at the end of each section.
Click on the grey arrow to start the animation running. The animation can be stopped and restarted at any point. A section can also be viewed again.
The red arrows that appear on the left after section one will return you to the very beginning of the animation.
The diagram below shows a gel electrophoresis plate which has been used to separate DNA fragments produced as a result of the DNA sequencing process shown above.
All of the DNA fragments started at the bottom of the plate. The current during electrophoresis flowed in such a way that they were carried up the plate in the direction of the arrow.
Use your knowledge of DNA sequencing, together with the information from the electrophoresis, to work out the sequence of the original strand of DNA, starting at the 5' end.
Enter your answers by selecting the correct nucleotide base from the drop down menu under each section of the strand.
Click on the button at the bottom of the page to see if you have worked out the sequence correctly.