Pack 11 DNA & bioinformatics

DNA & bioinformatics applies regex to genetic sequences. DNA is written with four letters, A, C, G and T, and its rules map neatly onto character classes, anchors and counted repeats. You don’t need any biology: each board states its rule.

The first board catches valid DNA only, so ACGT is caught and ACGU is spared. Then you catch sequences that start with the start codon ATG, ones that end with a stop codon such as TAA, sequences whose length is a multiple of three, and RNA, where U takes the place of T, as in GCAU.

Every level also has hidden checks: words you don’t see. Passing the words on screen solves a level; passing the hidden checks too ranks it.

Codons are a good excuse to practise grouped repeats, which the Quantifiers track explains. For another notation with strict rules, try Chess notation.