The caribou travel great distances each winter to find food, often moving in large herds across the tundra. What is a caribou?

• A type of fish found in northern lakes

• A large deer species that migrates seasonally

• A type of bird known for its long-distance flight

• A species of bear that hunts in the Arctic

The destruction of a single species can disrupt an entire ecosystem, affecting both plants and animals that depend on it. What is an ecosystem?

• A group of predators hunting together

• A collection of deserts and forests

• A community of living things interacting with their environment

• A group of scientists studying wildlife

Scientists recently discovered a new organism living in the deep ocean, surviving in extreme heat and pressure. What is an organism?

• A non-living rock formation

• Any living thing, such as a plant, animal, or microbe

• A type of underwater volcano

• A machine designed to explore the ocean

The bald eagle was once an endangered species, but conservation efforts have helped increase its population. What does endangered species mean?

• A species that has recently evolved

• A species with a large, thriving population

• A species at risk of extinction

• A species that only lives in zoos

In harsh environments like the Arctic, lichen grows on rocks and tree bark, providing an important food source for some animals. What is lichen?

• A type of fungus that lives on decaying animals

• A combination of a fungus and an alga that grows together

• A type of moss that only grows in deserts

• A plant that requires large amounts of sunlight

The overuse of natural resources can lead to shortages of water, food, and shelter for both humans and animals. What are resources?

• Tools used for scientific research

• Materials that living things rely on to survive

• Locations where animals hibernate

• Laws that protect the environment

The 21st century has brought many technological advancements, changing the way people communicate and travel. What is a century?

• A period of 50 years

• A period of 100 years

• A period of 500 years

• A period of 1,000 years

Many birds migrate south during the winter to find warmer climates and food sources. What does migrate mean?

• To build nests for their young

• To move from one region to another seasonally

• To stay in one place all year

• To gather in large groups for protection

Scientists study how different species populate new environments after natural disasters. What does populate mean?

• To leave an area permanently

• To increase the number of organisms in a place

• To destroy a habitat

• To create artificial ecosystems

Desert plants have adapted to survive long periods without rain by storing water in their stems. What does survive mean?

• To continue living despite challenges

• To absorb sunlight for energy

• To grow quickly in warm climates

• To produce large flowers and seeds