Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

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

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

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

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

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

Describe the scientific reasons for the success of Mendel’s experimental work
Describe the expected outcomes of monohybrid crosses involving dominant and recessive alleles
Apply the sum and product rules to calculate probabilities

In this video collaboration from Khan Academy and 23andMe, you'll learn how chromosomes and genes are passed down from parent to child.

In this video collaboration from Khan Academy and 23andMe, you'll learn how chromosomes and genes are passed down from parent to child.

In this video collaboration from Khan Academy and 23andMe, you'll learn how your observable traits, or phenotypes, are the result of interactions between your genes and environment.

In this video collaboration from Khan Academy and 23andMe, you'll learn how your observable traits, or phenotypes, are the result of interactions between your genes and environment.

In this video collaboration from Khan Academy and 23andMe, you'll find out why women don't have a Y chromosome. Even with no Y, women can still learn about their paternal ancestry with genetic testing from services like 23andMe.