Genetics & DNA: an interactive genetics course

Genetics & DNA is an interactive genetics course that goes from the structure of DNA to how traits are inherited and how genes are edited. Its 24 short sections cover base pairing, DNA replication, transcription and translation, mutations, alleles and Punnett squares, mitosis and meiosis, genetic engineering and CRISPR, each with a 3D model, an animation or a practice question.

It suits students revising genetics for school exams and anyone who wants to understand the science behind headlines about DNA tests and gene therapy.

What the genetics course covers

From DNA to protein

The first half follows one idea all the way through. A gene is a stretch of DNA holding the recipe for one protein. The cell copies the gene into messenger RNA in the nucleus (transcription), then a ribosome reads that message three bases at a time and joins amino acids into a chain (translation). The course uses the real HBB gene, which makes part of haemoglobin, so you can see how changing a single base changes the protein.

Inheritance

The second half moves from molecules to families. You meet alleles, dominant and recessive, genotype and phenotype, then use Punnett squares to predict offspring, including the 3 to 1 ratio Gregor Mendel found in pea plants. Meiosis explains where the variation comes from: with 23 chromosome pairs splitting at random, one person can make 2²³, or over 8 million, different combinations in their sex cells, before crossing over mixes things further.

Editing genes

The course ends with genetic engineering and CRISPR-Cas9, where a guide RNA leads an enzyme to cut DNA at one exact spot. It finishes with a real example: Casgevy, which the UK medicines regulator authorised in November 2023 as the first CRISPR medicine, to treat sickle cell disease.

Try a question from the course

Bases always pair the same way: A with T, and G with C. So if one strand reads A T G C C A, its partner reads T A C G G T. A to T pairs are held by two hydrogen bonds and G to C pairs by three, which is part of the course's section 3.

Now build the partner of a new strand, then press Mark to check it in the course.

Who this course is for

• School students revising DNA, protein synthesis, inheritance and meiosis, who want to see the processes move instead of reading about them.
• Adults new to biology who want a clear, short route to what genes are and how gene editing works.
• Teachers looking for animations and quick checks to use in a lesson.

What you need to know first

The course page suggests Cell Biology first. It helps to know what a cell, its nucleus and a protein are, because the genetics course starts inside the nucleus. You also need simple probability for Punnett squares: four equally likely boxes, so each one is a 1 in 4 chance. The Probability course covers that if it is new.

How long it takes

There are 24 sections, and most take a few minutes, as each is a short explanation and one interactive part. Learners without a plan can open two sections of a course a day, in order, so the whole course takes 12 days that way. A plan removes the daily limit and lets you go straight to any section, such as Punnett squares before an exam.

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