The Malpighian tubules of insects are an excellent model for examining the properties of secretion in a transporting epithelium. In this exercise students expose tubules from cockroaches or crickets to chlorophenol red and visually estimate the dye concentration in the lumen. By adding metabolic inhibitors and competitors or by substituting ion-free media they can demonstrate competition, specificity, and energy- or ion-dependence of active transport. Advanced students can design their own experiments after a review of the literature. This simple and inexpensive exercise provides students with a challenging and rewarding introduction to experimental design in the laboratory.

This "clicker case" follows Susan, an intern at a local hospital, who has admitted a patient she discovers has used the drug Ecstasy. The girl becomes delirious, and Susan begins to suspect that she may be suffering from water intoxication. The case is designed for an introductory biology course for either science or non-science majors, though it could be adapted for upper level courses. It uses an example of water intoxication to introduce membrane structure and function, osmosis, and electrolyte balance in the body. The case itself is a PowerPoint presentation (~800KB) shown in class that is punctuated by multiple-choice questions students answer using clickers. It could be adapted for use without these technologies.

In this fictionalized story, John and Jane, whose new baby is born with Down syndrome, are suing the prenatal clinic where Jane received her care, blaming the clinic for the baby's condition. Designed for an introductory biology course, this "clicker case" has students assume the role of an expert witness hired by a law firm to give evidence in the case. To help determine the cause of "Baby Doe's" condition and whether anyone can be held responsible for it, students need to help the jury understand the process of cell division. In particular, they must explain the behavior of the chromosomes during cell division and how errors in this process can result in conditions such as Down syndrome. The case is presented in class using PowerPoint slides (~1.8 MB) that are punctuated by multiple-choice questions the students respond to using hand-held personal response systems, or clickers. It could be adapted for use without these technologies.

This "clicker case" is based on the General Biology edition of James Hewlett's "Bad Fish" case in our collection. The case follows the story of biologist Dr. Westwood, who is accidentally poisoned, first while traveling in Asia and then in the South Pacific. Students learn about Dr. Westwood's experiences and about nerve cell physiology-focusing especially on the role of ion channels in maintaining and changing electrical gradients across the cell membrane (resting potential and action potentials). They then apply what they learn in each part of the case to determine the mechanism of neurotoxin poisonings described in the case. The case is presented in class via PowerPoint (~2MB). Students use personal response systems, or "clickers," to answer the multiple-choice questions that punctuate the PowerPoint presentation as they explore the underlying mechanism of Dr. Westwood's poisoning.

In this version, developed for classes in cell and molecular biology, the protagonist of the case, Dr. Westwood, survives an accidental poisoning-not once, but twice. Students read about each incident, applying what they learn in each part of the case to the later sections, and then design a drug to treat the neurotoxin poisoning described in the story. The case comes in three different versions, or editions. This is the Cell & Molecular Biology Edition, which has a different set of questions than the General Biology Edition or the Human Anatomy& Physiology Edition, also in our collection.

In this version, developed for a course in general biology, the protagonist of the case, Dr. Westwood, survives an accidental poisoning-not once, but twice. Students read about each incident, applying what they learn in each part of the case to the later sections, and then design a drug to treat the neurotoxin poisoning described in the story. The case comes in three different versions, or editions. The General Biology Edition is designed for an introductory biology course. Its basic storyline and core objectives are carried over into a Human Anatomy& Physiology Edition and a Cell& Molecular Biology Edition, also in our collection, each of which has its own set of questions.

This resource uses a student-designed laboratory exercise as a model to demonstrate the techniques and concepts surrounding the scientific method.

This 14-minute video lesson provides an overview of B cells (B lymphocytes) and how they are activated and produce antibodies. [Biology playlist: Lesson 53 of 71].

This 13-minute video lecture provides an introduction to what cancer is and how it is the by-product of broken DNA replication. [Biology playlist: Lesson 13 of 71].

This 10-minute video lesson discusses how cytotoxic T-Cells get activated by MHC-I/antigen complexes and then proceed to kill infected cells. [Biology playlist: Lesson 56 of 71].

This 19-minute video lesson looks at diffusion and osmosis. [Biology playlist: Lesson 36 of 71].

This 2-minute video lesson provides an overview of early development of a zygote to an embryo. It also discusses embryonic and somatic stem cells. [Biology playlist: Lesson 12 of 71].

This 13-minute video lesson provides an overview of glycolysis. [Biology playlist: Lesson 24 of 71].

This 21-minute video lesson provides an introduction to helper T-Cells and their role in activating B cells. [Biology playlist: Lesson 55 of 71].

This 14-minute video lesson presents an introduction to cellular respiration, glycolysis, the Kreb's Cycle, and the electron transport chain. [Biology playlist: Lesson 21 of 71].

This 18-minute video lesson looks at mitosis, meiosis and sexual reproduction. It also covers understanding gametes, zygotes, and haploid/diploid numbers. [Biology playlist: Lesson 9 of 71].

This 21-minute video lesson examines parts of a cell: nucleus, ribosomes, endoplasmic reticulum, Golgi bodies, mitochondria, chloroplasts, vacuoles, and vesicles. [Biology playlist: Lesson 35 of 71].

This 27-minute video lesson looks at the phases of Meiosis. [Biology playlist: Lesson 11 of 71].

This 21-minute video explains the phases of mitosis. [Biology playlist: Lesson 10 of 71].