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:

Understand how the cell cycle is controlled by mechanisms that are both internal and external to the cell
Explain how the three internal “control checkpoints” occur at the end of G1, at the G2/M transition, and during metaphase
Describe the molecules that control the cell cycle through positive and negative regulation

Cancer is a leading cause of death worldwide. Cancer involves uncontrolled cell growth, resistance to cell death, failure to differentiate into a particular cell type, and increased cellular motility. A family of gate-keeper genes, known as tumor suppressor genes, plays important roles in preventing the initiation and progression of cancer. Among these, p53 is the most famous. Because of its essential role in maintaining genomic integrity, p53 is often called the guardian of the genome. During this course, we will study how p53 serves as a pivotal tumor suppressor gene in preventing cancer.This course is one of many Advanced Undergraduate Seminars offered by the Biology Department at MIT. These seminars are tailored for students with an interest in using primary research literature to discuss and learn about current biological research in a highly interactive setting. Many instructors of the Advanced Undergraduate Seminars are postdoctoral scientists with a strong interest in teaching.