One of the failed hypothetical models of DNA is Linus Pauling's triple helix model. This structure would be unstable under normal cellular conditions.
During the process of trying to elucidate the structure of DNA, Jim Watson made some cardboard models to try to understand how DNA nucleotides are paired. It helped him visualize how hydrogen atoms of paired nucleotides interact with each other to form a symmetrical structure that fits the...
Scientists have pieced together the evolutionary history of the Antarctic icefish. The icefish makes an excellent case study for genetic evolution as both the gain and loss of genes have led to key adaptations.
The following classroom-ready resources complement The Making of the Fittest: The Birth and Death of Genes, which describes how scientists have pieced together the evolutionary history of the Antarctic icefish. The icefish makes an excellent case study for genetic evolution as...
The Double Helix is the story of the scientists and evidence involved in one of the most important scientific quests of the 20th century: the discovery of the structure of DNA.
The following classroom-ready resources complement The Double Helix. This short film describes the evidence that led James Watson and Francis Crick to the discovery of the double-helical structure of DNA and how the structure immediately revealed how genetic information is stored and...
This activity can be used in conjunction with the short film The Double Helix. It introduces students to the classic experiment by Matthew Meselson and Franklin Stahl, which revealed that DNA replication follows the semiconservative model.
Embedded quiz modules test students’ understanding as they watch the short film on the icefish—an example of how genes are reused and recycled.