Students will write, graph, and solve direct variation models for real-world problems. Students examine guided notes, review guided practice, study vocabulary, watch instructional videos and attempt practice problems.

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This comprehensive study guide highlights the main terms and formulas needed to understand graphs of rational functions. Examples are included.

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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:

Describe how scientists developed the present-day theory of evolution
Define adaptation
Explain convergent and divergent evolution
Describe homologous and vestigial structures
Discuss misconceptions about the theory of evolution

This activity provides an introduction to natural selection and the role of genetic variation by asking students to analyze illustrations of rock pocket mouse populations (dark/light fur) on different color substrates in the Sonoran Desert (light/dark) over time. Based on this evidence, and what they learn about variation and natural selection in the accompanying short film, students use this evidence to explain the change in the rock pocket mouse populations on the lava flow (dark substrate) over time. This is one of several classroom activities, focusing on related topics and varying in complexity, built around the short film. This ten minute film shows adaptive changes in rock pocket mouse populations, demonstrating the process of natural selection and can be accessed at http://www.hhmi.org/biointeractive/making-fittest-natural-selection-and-adaptation. The film is also available as an interactive video with embedded questions, which test students’ understanding as they watch the film.

Overview of the basic concepts behind evolution, such as gene variation and adaptations.[Free Registration/Login may be required to access all resource tools.]

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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. [32:01]

This website offers a clear definition of the science of Genetics, highlighting DNA and genes. There is a neat, easy-to-understand animated tour of the basics and an opportunity to go inside an animated cell. Student can build a DNA molecule and discover how proteins function. Teachers and students alike will enjoy "What Makes a Firefly Glow?" Among others, there is a student activity based on using DNA to solve a mystery of stolen artifacts. The great teacher resources supply guides and suggest classroom activities. All in all, this is a useful site whose simple interactive graphics provide a fun and easy way to learn the difficult subject of DNA.

This video segment from NOVA: "Cracking the Code of Life" explores the genetic similarities and differences among organisms.

This pathway explores how we inherit our phenotypes and the origin of genetic diseases.

This site from Palomar College describes the conditions needed for theHardy-Weinberg Principle to hold true.Completes sample calculations involvingthis principle.

Here is a site that clearly and thoroughly explains direct and inverse variation. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to students who have been absent or who need additional instruction on this or many other topics.

This site from Palomar College contains an interactive practice quiz containingfour questions on major concepts regarding gene flow. A great learning tool.

An introduction to Mendelian Genetics and inheritance. [5:10]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

The mathematics resource assesses students on linear relations. The activity has problems with graphing and analyzing linear relations. Some of the topics included are variation, scatter plots and linear relationships. The worksheet has problems, challenge activities, and an extension activity.

Understand how variation can be introduced into a species. [19:52]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Find a quick, concise explanation of Combined Variation. Hyperlinks are available to explain how variables can vary directly and inversely.