The computer program's simulation of a Sonoran desert community should ultimately strengthen the student's comprehension of what is required for a natural ecosystem to sustain itself (remain in balance). This computer simulation program has great flexibility. It allows the student to manipulate the population numbers of five Sonoran Desert species. A species natural history attachment provides vital information for the students to familiarize themselves with each species' behaviors, its niche and food resource needs. The program includes two producers, the Saguaro cactus and the Ironwood Tree. It also includes 3 consumers, but their interactions both toward the producers and each other differ. The community's ability to remain in balance and sustain all five species so that none die out rests on the student's assessment skills enabling him to correctly identify these dependencies. The student learns by trial and error as he continues to fine tune the ecosystem that he maintains stewardship of.

Explore how populations change over time in a NetLogo model of sheep and grass. Experiment with the initial number of sheep, the sheep birthrate, the amount of energy sheep gain from the grass, and the rate at which the grass re-grows. Remove sheep that have a particular trait (better teeth) from the population, then watch what happens to the sheep teeth trait in the population as a whole. Consider conflicting selection pressures to make predictions about other instances of natural selection.

The levels of contaminants found in particular animals vary widely depending on where they fit into the Arctic food chain, as described in this video segment adapted from LOKE Films and the Arctic Monitoring and Assessment Programme.

In this video segment adapted from LOKE Films and the Arctic Monitoring and Assessment Programme, learn how human populations in the Arctic are affected by industrial contaminants in the food chain.

Smithsonian Education presents Contrasts in Blue: Life on the Caribbean Coral Reef and the Rocky Coast of Maine. Teachers can download this comprehensive teaching package in which students explore two marine ecosystems, the coral reefs of the Caribbean and the state of Maine's rocky coastline. This amazing teaching package comes complete with background information, pictures and maps, student handouts, teacher answer keys, and a list of resources. Through this study students will gain an understanding of our world being one large ecosystem in which seemingly unrelated environments are in fact inevitably linked.

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 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.

Defenders of Wildlife provides information and interactive media to teach students about planet Earth and its' inhabitants. Students can research endangered species (over 50 listed here), learn how to defend and protect the environment, see how the web of life works and other engaging activities.

A comprehensive guide to national invasive species, including alien plants, animals, and microbes. An invasive species is one that is likely to cause environmental or human harm.

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

This video segment from Outdoor Nevada examines threats to the desert tortoise population.

This lab activity allows students to indetify macroinvertebrates and determine the health of an acquatic ecosystem.

This article provides links to web sites that describe the Arctic and Antarctica in terms of geography, climate, and ecosystems.

In this Dinosaur Train clip, Mr. Conductor explains to the Pteranodon kids that all creatures have their own part to play in an ecosystem. This resource teaches students that all organisms in an ecosystem are connected, and the difference between herbivores, carnivores, and omnivores. [1:33]

In this video segment from NatureScene, observe some methods of plant identification with regards to the diversity of hardwoods at the Congaree Swamp.

This video segment from the Science and Technology Chat series focuses on dolphin pregnancy, birth, and care of the young, and features Atlantic bottlenose dolphins living in captivity at the Mirage Resort Dolphin Habitat.

This video segment from Kentucky Life explains the differences between dragonflies and damselflies and explores their habitats.

This EPA website has links to many science topics about which the Environmental Protection Agency has concerns.