This interactive will present the mathematical consideration of exponentially
enriching a piece of DNA using PCR. Typically, a PCR protocol will repeat
approximately 30 cycles of denaturation, annealing, and elongation. 30 cycles of
PCR produce around 1 billion copies of the amplified region.

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 functions proteins perform in the cell and in tissues
Discuss the relationship between amino acids and proteins
Explain the four levels of protein organization
Describe the ways in which protein shape and function are linked

PCR, or polymerase chain reaction, is a powerful lab technique used to generate billions of copies of a specific stretch of DNA. This video animation illustrates the process of PCR.

This lab video demonstrates how to perform a PCR (Polymerase Chain Reaction) in the laboratory setting.

This interactive will present the components and steps needed for a successful
PCR reaction.

This interactive will present the rules for designing precise nucleotide sequences
called PCR primers. Designing primers for a PCR reaction is an important step
because the way they bind to the template DNA dictates much of the success of
the PCR reaction.

Polymerase Chain Reaction - or PCR - is known as one of the most ubiquitous and powerful techniques in life science laboratories. PCR is a highly sensitive and selective method to produce many copies of a particular piece of DNA. This pathway details applications of PCR, its mechanism and primer design, and demonstrates how the method is used in the lab.