K'NEX RSS Feeds - Secondary School: Biology; Life Sciences Sitemap http://www.knex.com Copyright 2012. All Rights Reserved DNA, Replication and Transcription Set includes 521 K NEX Rods and Connectors and a 24 page full color building instruction booklet. Builds 11 DNA and mRNA molecules. Build any one from 19 combinations at once. Wonderfully flexible set allows students to build and learn using models that d... http://www.knex.com/Educators/dna_replication_transcription.php