The author explains heat transfer and how it applies to living in extremely cold environments.

In this video segment, ZOOM guest Cassie takes us on a tour of the coral reef near her home in Key Largo, Florida, and points out some of its unique features.

In this video excerpt from NOVA, find out how whole genome sequencing saved the life of Alexis, a fraternal twin who was originally diagnosed with cerebral palsy but, in fact, had an even rarer genetic condition.

This article profiles Linda Deegan, scientist with the Arctic Long-Term Ecological Research site in the Kuparuk River region of Alaska, as she counts and tags Arctic grayling as they migrate from streams to lakes in the fall.

This activity is a field investigation where students observe plants, animals, and insects that are common to Minnesota.

In this lesson, students find their location on a map using Latitude and Longitudinal coordinates. They determine where they should go to be rescued and how best to get there.

Students learn how DNA fingerprinting has been used in criminal investigations and discuss the limitations of and problems with DNA testing.

Students perform DNA forensics using food coloring to enhance their understanding of DNA fingerprinting, restriction enzymes, genotyping and DNA gel electrophoresis. They place small drops of different food coloring ("water-based paint") on strips of filter paper and then place one paper strip end in water. As water travels along the paper strips, students observe the pigments that compose the paint decompose into their color components. This is an example of the chromatography concept applied to DNA forensics, with the pigments in the paint that define the color being analogous to DNA fragments of different lengths.

Explore the relationship between the genetic code on the DNA strand and the resulting protein and rudimentary shape it forms. Through models of transcription and translation, you will discover this relationship and the resilience to mutations built into our genetic code. Start by exploring DNA's double helix with an interactive 3D model. Highlight base pairs, look at one or both strands, and turn hydrogen bonds on or off. Next, watch an animation of transcription, which creates RNA from DNA, and translation, which 'reads' the RNA codons to create a protein.

This nonfiction article, written for students in grades 4-5, explores the life and seasonal migration of the sanderling bird. Modified versions are available for students in younger grades.

The dark reactions of photosynthesis (Calvin Cycle) are presented in this learning experience to show where these processes take place in the plant as well as the specific reactions involved.

This video segment from Evolution: "Darwin's Dangerous Idea," together with interviews with Daniel Dennett and James Moore, depicts Darwin struggling with publicizing his revolutionary theory.

In this video segment adapted from NOVA, scientists search for carbonized remains of plants preserved in lava flows to find out how long it has taken rain forests on Hawaii to regenerate after a volcanic eruption.

Without the work of decomposers, living organisms would eventually use up all the raw materials in the environment, and dead organisms and wastes would pile up. This video segment from Interactive NOVA: "Earth" describes the role of decomposers as the earth's great recyclers.

In this visualization adapted from the University of Massachusetts Medical School, discover the role that dengue viral proteins play in a human cell as the virus prepares to replicate.

Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.

In this lab activity, students determine density differences of water samples with varying temperature and salinity levels. Students synthesize information to predict the effects of oil in given water samples.

This is an integration of science leaf observations with musical composition for early elementary students.

How are species able to survive in a desert? tudents will be able to explain how plants and animals are adapted to a desert and how those adaptations help them survive and reproduce.

This video segment from NOVA: A Desert Place describes the physical characteristics and organisms that define the desert biome.