In this module, we'll explore the molecular structure of DNA. What is DNA? What are the basic building blocks of DNA? Where can you find DNA within a cell? We'll learn about how James Watson and Francis Crick were able to solve the riddle of the molecular structure of DNA by building on the work of other scientists. Their groundbreaking discovery revealed that four nucleobases (adenine, thymine, cytosine, and guanine) combine with sugar and phosphate molecules to form the familiar double helix of DNA. We'll take a look at how the molecular structure of DNA regulates its functions; for example, how the chemical bonds (covalent and noncovalent) between these molecules allow DNA to "unzip" during replication. Then we'll take a look at how you manage to fit over three billion base pairs into each of your cells. (Here's a hint: Histones, nucleosomes, and chromosomes would be great at packing for a trip!)

We've all heard DNA described as "the blueprint of life," but what does that actually mean? Each one of the approximately 20,000 genes in our bodies contains the instructions for building a protein. In this module, we'll explain how RNA copies the genetic information contained in our genes and uses this information to assemble amino acids into proteins. Scientists call this concept "Central Dogma": DNA makes RNA and RNA makes protein. We'll also explore how we transmit genetic information from one cell to another -- and what happens when things go wrong. Along the way, we'll learn about techniques (such as polymerase chain reactions and gel electrophoresis) that forensic scientists use in DNA fingerprinting. Join us this week for murder and mayhem in the lab!

In this module, we'll explore the techniques scientists use to manipulate DNA. Genetic engineering has allowed us to increase crop yields, diagnose illnesses, develop vaccines, and manufacture insulin. By carefully selecting a pair of molecular scissors (restriction enzymes), scientists are able to isolate a gene of interest and insert it into plasmid DNA, turning a common bacteria (E. coli) into a molecular copying machine. This week, we'll learn that mutations are genetic errors, but that not all mutations are necessarily bad — in fact, some mutations confer a selective advantage that protects against disease. We'll explain what genetically modified organisms are (and what they are not) and weigh in on the heated debates about the ethics and safety of GMOs in popular media.