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 that meiosis and sexual reproduction are evolved traitsIdentify variation among offspring as a potential evolutionary advantage to sexual reproductionDescribe the three different life-cycle types among sexual multicellular organisms and their commonalities

By the end of this section, you will be able to:Describe the behavior of chromosomes during meiosisDescribe cellular events during meiosisExplain the differences between meiosis and mitosisExplain the mechanisms within meiosis that generate genetic variation among the products of meiosis

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 meiosisUse the forked-line method and the probability rules to calculate the probability of genotypes and phenotypes from multiple gene crossesExplain the effect of linkage and recombination on gamete genotypesExplain the phenotypic outcomes of epistatic effects between genes

By the end of this section, you will be able to:Discuss Sutton’s Chromosomal Theory of InheritanceDescribe genetic linkageExplain the process of homologous recombination, or crossing overDescribe how chromosome maps are createdCalculate the distances between three genes on a chromosome using a three-point test cross

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.

The topic of this video module is genetic basis for variation among humans. The main learning objective is that students will learn the genetic mechanisms that cause variation among humans (parents and children, brothers and sisters) and how to calculate the probability that two individuals will have an identical genetic makeup. This module does not require many prerequisites, only a general knowledge of DNA as the genetic material, as well as a knowledge of meiosis.

The principles of genetics with application to the study of biological function at the level of molecules, cells, and multicellular organisms, including humans. Structure and function of genes, chromosomes and genomes. Biological variation resulting from recombination, mutation, and selection. Population genetics. Use of genetic methods to analyze protein function, gene regulation and inherited disease.

Students randomly select jelly beans (or other candy) that represent genes for several human traits such as tongue-rolling ability and eye color. Then, working in pairs (preferably of mixed gender), students randomly choose new pairs of jelly beans from those corresponding to their own genotypes. The new pairs are placed on toothpicks to represent the chromosomes of the couple's offspring. Finally, students compare genotypes and phenotypes of parents and offspring for all the "couples" in the class. In particular, they look to see if there are cases where parents and offspring share the exact same genotype and/or phenotype, and consider how the results would differ if they repeated the simulation using more than four traits.

Students learn about mutations to both DNA and chromosomes, and uncontrolled changes to the genetic code. They are introduced to small-scale mutations (substitutions, deletions and insertions) and large-scale mutations (deletion duplications, inversions, insertions, translocations and nondisjunctions). The effects of different mutations are studied as well as environmental factors that may increase the likelihood of mutations. A PowerPoint® presentation and pre/post-assessments are provided.

In a class discussion format, the teacher presents background information about basic human genetics. The number of chromosomes in both body cells and egg and sperm cells is covered, as well as the concept of dominant and recessive alleles. Students determine whether or not they possess the dominant allele for the tongue-rolling gene as an example.