Unit D: Changes in Living Systems

Bees are important for agriculture. But bee populations face threats. This resource looks at Colony Collapse Disorder, herbicides & pesticides, and more.

When fertilizers from agriculture get into lakes and rivers, big problems can result for aquatic ecosystems, food chains & webs!

images of some birds in the process of building their nests

10 images of some birds' nests showing various designs, structures and materials used for building them

5 images of predatory birds that hunt and feed on other animals such as eagles, the Great Horned Owl and vultures

10 images of some birds such as finches, chickadees and cardinals that produce sounds and calls in a musical way

Beavers are a Canadian symbol. But in South America, they’re considered an invasive species.

4 images of some birds such as emus and penguins that have less developed or small wings and have evolved over time not to be able to fly

4 images of some birds that are heavy-bodied and ground feeders such as turkeys, pheasants and peacocks

12 images of some cold-blooded animals such as frogs and newts classified as amphibians that can live in the water or on land

11 images of some animals such as lizards and Arctic Hares whose appearance has adapted to provide protection in their environments

20 images of animal pairs such as polar bears, turtle, dogs and birds in their juvenile and adult stages of life

10 images of some animals such as bears, bats, turtles and lemurs that spend the cold weather in a dormant state

10 images of some animals such as salmon, Monarch butterflies, whales, zebras and wildebeast that move seasonally from one region to another

5 images of invertebrates such as spiders and scorpions characterized by having 4 pairs of segmented legs, 2 main body parts and simple eyes