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:

Explain Mendel’s law of segregation and independent assortment in terms of genetics and the events of meiosis
Use the forked-line method and the probability rules to calculate the probability of genotypes and phenotypes from multiple gene crosses
Explain the effect of linkage and recombination on gamete genotypes
Explain the phenotypic outcomes of epistatic effects between genes

Find out what happened when Mendel crossed two hybrid pea plants. The animations do a good job explaining why these crosses produce a 3:1 ratio of traits.

This resource explains Mendel's first law (Law of Segregation) in detail. Includes Mendel's original experiments with results and conclusions.