Analyzing Allele Frequencies for D4.1 in the New IBDP Biology Course

I have officially been teaching the brand new IBDP Biology course for a month now and while I am able to use some of my material from the old syllabus (organized in a new way), there are brand new things to figure out. So far, the most challenging of these new things has been in my HL lesson on Natural Selection in Subtopic D4.1.

From the syllabus:

D4.1.10 —Allele frequencies of geographically isolated populations.

Application of skills: Students should use databases to search allele frequencies. Use at least one human example.

If you haven't noticed already, the new syllabus format includes details such as applications, Nature of Science (NOS) connections and specific examples to include directly below the content statement. (see the image below to clarify, it is taken directly from the 2025 IBDP Biology Subject Guide.)

I was shocked that this simple statement ended up taking me about two hours to figure out... the first step was to find a database that was free, offered data on allele frequencies in different populations and was accessible to my students. After looking at several options I decided to go with the National Library of Medicine National Center for Biotechnology Information SNP Database, linked here. After looking at a variety of examples, YouTube videos & websites (one particularly useful one in italian, thank you Google Translate). I was able to figure out how teach my students to search for human allele frequencies in the SNP database.

You can see the slides I put together in the space below.

As you can see, I simply had students use the SNP (Single Nucleotide Polymorphism) database and search for Homo sapiens since the guide specified a human gene. Luckily, we had already learned about SNPs in Subtopic A3.1 Diversity of Organisms and our discussion about genomes. They will come up again when we do Subtopic D1.3 Mutation & Gene Editing. This new syllabus is very spiral in nature and we come back to the same ideas multiple times.

I had students examine SNP rs248 simply because it showed up on the first page of the search and had both a variety of sources and included many geographic regions, addressing the connection to geographically isolated populations. This particular SNP is found on Chromosome 8 and includes only two alleles, one with Guanine "G" and the other with Adenine "A", as you can see on the last image above the "G" base is much more common than the SNP "A". This gene codes for LPL (lipoprotein lipase) one of the lipase enzymes found in the heart, muscle and adipose tissue of humans. This connects further to C1.1 Enzymes & Metabolism as well as to D2.2 Gene Expression where students are asked to examine an example of a protein being expressed, such as an enzyme. It also connects to B1.1 Carbohydrates & Lipids. Luckily, I seem to have chosen an ok example, although I think I can find an even better example for next time.

The next time I teach this subtopic I hope to have the time to develop an assignment using this database where we are able to look more closely at geographically isolated populations and examine specific allele frequencies. When I get this figured out and tested I will be sure to put it up in my TPT shop for any interested teachers. For now, I hope these screenshots and links will help. It's going to be a busy year with this new syllabus and I hope this saves you some time!

Thanks for reading teachers, travelers and curious souls of all kinds!

The Roaming Scientist