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 the relationship between genotypes and phenotypes in dominant and recessive gene systems
Develop a Punnett square to calculate the expected proportions of genotypes and phenotypes in a monohybrid cross
Explain the purpose and methods of a test cross
Identify non-Mendelian inheritance patterns such as incomplete dominance, codominance, recessive lethals, multiple alleles, and sex linkage

A pedigree shows how a trait is inherited over several generations. This video/slideshow explains why pedigrees are important, and the key factors scientists consider when studying pedigrees. [24:30]