Replication of DNA « Richmondschoolbiology’s Weblog

Before cell division can take place DNA has to be copied. It needs to be copied in such a way that there are no mistakes so the new strand of DNA is identical to the original. The process through which this is achieved is Semi-conservative replication.

Semi-conservative replication works on the principle that the organic bases in DNA fit together in complementary pairs (adenine is complementary to thymine, cytosine is complementary to guanine). So DNA can be copied by separating the two strands and then building up a complementary strand based on the bases on the original strand. In this way you get two DNA molecules which will be identical to each other as each strand has a new complimentary partner. It is called semi-conservative because the new molecules contain one of the original strands and one new strand, so half of the original DNA molecule has been conserved in this new one.

You need to know the process of semi-conservative replication including the roles of enzymes in the process. You should, of course, use your course book and the books in the library to learn this, but there are also animations here, here and here which might help you visualise the process.

It’s also important that you take time to consider how evidence was gathered to support this theory of replication. A good written explanation is here, whilst good animated explanations are to be found here and here.

As always, if you find any other good links to ideas covered in this post then please feel free to add a comment and share your find!

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