Mitosis and Meiosis
Mitosis and meiosis are types of biological cell division. I created three diagrams explaining mitosis and meiosis visually, on which I collaborated closely with my high school teacher, Dr Włodzimierz Wójcik. In 2008 I published the diagrams in Wikipedia under the Creative Commons. Since 2009 they have also been used in teaching in Poland and in the US.
In mitosis, a single somatic diploid cell divides into two identical diploid cells. In other words, a cell makes an exact copy of itself.
In meiosis, a single diploid cell divides into four haploid cells: gametes or meiospores. In other words, a cell splits into four reproductive cells (in humans it's egg or sperm cells).
Mitosis allows multicellular organisms to grow, build tissues, and replace cells. Meiosis enables sexual reproduction and contributes to genetic diversification in each new generation of organisms.
In 2008 I published the diagrams under the CC BY-SA 3.0 Creative Commons license. Since then, they have been adopted by 22 Wikipedia pages in 12 languages, used in high school and university teaching in Poland and USA, and published in books. They also come up on the first page of Google image search for "mitosis" and "meiosis".
It took me about 6 months to develop all three diagrams. Everything started with low-fidelity sketches, in which I could capture all scientific concepts agreed with Dr Wójcik.
We worked through several iterations. Once I managed to work out diagram structure in detail, I later progressed to sketching in higher fidelity and, ultimately, to digital production.