Learn about the antiparallel structure of DNA strands which can by 5 feet to 3 feet directionality. [9:57]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

A video discussing a variety of biotechnology applications that can be completed based on DNA's chemical properties. [2:44]

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Describe the structure of prokaryotic and eukaryotic genomes
Distinguish between chromosomes, genes, and traits
Describe the mechanisms of chromosome compaction

By the end of this section, you will be able to do the following:

Describe nucleic acids' structure and define the two types of nucleic acids
Explain DNA's structure and role
Explain RNA's structure and roles

Learn about deoxyribonucleic acid. Get an overview of DNA bases, complementary base pairing, and the structure of the double helix. [13:02]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Students reinforce their knowledge that DNA is the genetic material for all living things by modeling it using toothpicks and gumdrops that represent the four biochemicals (adenine, thiamine, guanine, and cytosine) that pair with each other in a specific pattern, making a double helix. They investigate specific DNA sequences that code for certain physical characteristics such as eye and hair color. Student teams trade DNA "strands" and de-code the genetic sequences to determine the physical characteristics (phenotype) displayed by the strands (genotype) from other groups. Students extend their knowledge to learn about DNA fingerprinting and recognizing DNA alterations that may result in genetic disorders.

Discover how the structure of DNA relates to its hereditary function in these videos from the American Masters film Decoding Watson. The first video, "DNA Structure and Function," [2:07] can be used with all middle and high school biology classes. The second video, "Discovering DNA," [0:55] is the Hereditary Material, contains advanced material and is more suited for students i n AP Biology classes. The accompanying classroom activity, appropriate for all students, explores how the building blocks of DNA assemble into a double helix. Additional support materials are available, including handouts, discussion questions and vocabulary.

As a class, students work through an example showing how DNA provides the "recipe" for making our body proteins. They see how the pattern of nucleotide bases (adenine, thymine, guanine, cytosine) forms the double helix ladder shape of DNA, and serves as the code for the steps required to make genes. They also learn some ways that engineers and scientists are applying their understanding of DNA in our world.

A nice tutorial on DNA structure. The menu at the bottom allows you to view some different information.

This narrated animation from Interactive NOVA: "The Secret of Life" illustrates DNA replication.

Read James Dewey Watson's Nobel Lecture "The involvement of RNA in the synthesis of proteins." This lecture, originally given December 11, 1962, is provided in PDF format.