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 epithelial tissues
Discuss the different types of connective tissues in animals
Describe three types of muscle tissues
Describe nervous tissue

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

List the basic components of the blood
Compare red and white blood cells
Describe blood plasma and serum

Defines and describes red blood cells and white blood cells, and describes the roles of platelets.

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This comprehensive study guide covers the main terms and concepts needed for a unit on the circulatory system.

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This 15-minute video lesson provides an introduction to the circulatory system and the heart. [Biology playlist: Lesson 39 of 71].

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.

Students will make a proportional model of blood out of red gelatin, a plastic bag, and rice. They will learn about the different components that make up blood and will investigate what happens when the arteries and veins experience buildup from cholesterol. They will then work in pairs to brainstorm ways to clean our clogged arteries.

Students are introduced to the circulatory system with an emphasis on the blood clotting process, including coagulation and the formation and degradation of polymers through their underlying atomic properties. They learn about the medical emergency of strokes the loss of brain function commonly due to blood clots including various causes and the different effects depending on the brain location, as well as blood clot removal devices designed by biomedical engineers.

This lesson will identify the cause and effects of various blood disorders. [5:21]

The purpose of this lesson is to teach students about blood and its components while instilling an appreciation of its importance for survival. The lesson takes a step-by-step approach to determining the "recipe" for blood while introducing students to important laboratory techniques like centrifugation and microscopy, as well as some diseases of cell types found in blood. [35:52]

Students are introduced to the circulatory system, the heart, and blood flow in the human body. Through guided pre-reading, during-reading and post-reading activities, students learn about the circulatory system's parts, functions and disorders, as well as engineering medical solutions. By cultivating literacy practices as presented in this lesson, students can improve their scientific and technological literacy.

This pathway provides and introduction to some of the systems of the body and the concept of homeostasis.

Students demonstrate the erythrocyte sedimentation rate test (ESR test) using a blood model composed of tomato juice, petroleum jelly and olive oil. They simulate different disease conditions, including rheumatoid arthritis, anemia, leukocytosis and sickle-cell anemia, by making appropriate variations in the particle as well as in the fluid matrix. Students measure the ESR for each sample blood model, correlate the ESR values with disease conditions and confirm that diseases alter blood composition and properties. During the activity, students learn that when non-coagulated blood is let to stand in a tube, the red blood cells separate and fall to the bottom of the tube, resulting in a sediment and a clear liquid called serum. The height in millimeters of the clear liquid on top of the sediment in a time period of one hour is taken as the sedimentation rate. If a disease is present, this ESR value deviates from the normal, disease-free value. Different diseases cause different ESR values because blood composition and properties, such as density and viscosity, are altered differently by different diseases. Thus, the ESR test serves as a real-world diagnostic screening test to identify indications of the presence of any diseases in people.

Although mom controls the oxygen source, the fetus has a couple of clever tricks to get the most oxygen possible! Rishi is a pediatric infectious disease physician and works at Khan Academy.

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.

This lesson describes how the circulatory system works, including the heart, blood vessels and blood. Students learn about the chambers and valves of the heart, the difference between veins and arteries, and the different components of blood. This lesson also covers the technology engineers have developed to repair the heart if it is damaged. Students also understand how the circulatory system is affected during spaceflight (e.g., astronauts lose muscle in their heart during space travel).

Using ordinary household materials, student “biomedical engineering” teams design prototype models that demonstrate semipermeability under the hypothetical scenario that they are creating a teaching tool for medical students. Working within material constraints, each model consists of two layers of a medium separated by material acting as the membrane. The competing groups must each demonstrate how water (or another substance) passes through the first layer of the medium, through the membrane, and into the second layer of the medium. After a few test/evaluate/redesign cycles, teams present their best prototypes to the rest of the class. Then student teams collaborate as a class to create one optimal design that reflects what they learned from the group design successes and failures. A pre/post-quiz, worksheet and rubric are provided.

Your blood gives doctors all kinds of clues about your health. It's normal to be nervous about this test, but no one loves needles! What you may not know? Most blood draws take less than a minute. [2:01]