Grade 3
Animals and Ecosystems
Animal groups, fossils, habitats, survival, and environmental change.
3-LS2-1, 3-LS4-1, 3-LS4-3, 3-LS4-4
4 lessons
100 quiz questions
Lesson 1: Animal Groups and Survival
Learn how some animals live in groups that help members survive.
Learning goals
- Identify examples of animal groups.
- Explain how groups can help animals find food or stay safe.
- Use evidence to support an argument about group behavior.
Some animals live in groups
Many animals spend part or all of their lives in groups. Examples include a flock of geese, a herd of cattle, a school of fish, a swarm of bees, and a pod of whales.
Groups can help animals survive
Groups may help animals find food, defend themselves, care for young, keep warm, or travel. The size and purpose of groups can be very different from species to species.
Arguments need evidence
A scientific argument uses evidence. If you claim that living in a group helps bees survive, evidence might include bees working together to find food, protect the hive, and care for young.
Lesson 2: Fossils and Past Environments
Use fossil evidence to learn about organisms and environments from long ago.
Learning goals
- Describe fossils as evidence of past life.
- Use fossil data to infer past environments.
- Explain that some organisms that lived long ago are now extinct.
Fossils are evidence
Fossils are preserved remains or traces of organisms that lived long ago. Fossils can include bones, shells, footprints, leaves, or impressions.
Fossils tell about environments
Fossils can give clues about what an environment was like. Marine fossils found on dry land suggest that the area may once have been underwater. Tropical plant fossils in a cold place suggest the climate was different long ago.
Some organisms are extinct
Some plants and animals that lived in the past are no longer found anywhere on Earth. Fossils help scientists learn about these extinct organisms.
Lesson 3: Habitats and Survival
Compare how well organisms survive in different habitats.
Learning goals
- Describe a habitat as a place where organisms live.
- Explain that organisms have needs and characteristics.
- Use evidence to decide whether an organism can survive well in a habitat.
Habitats provide needs
A habitat is a place where an organism lives. Habitats provide things organisms need, such as food, water, shelter, air, space, and the right temperature range.
Organisms fit some habitats better than others
An organism may survive well in one habitat but poorly in another. A cactus survives well in a dry desert but would not survive well in a dark pond. A fish survives well in water but not on dry land.
Parts of a system interact
A habitat and the organisms living there form a system. Plants, animals, water, soil, sunlight, and temperature interact. A change in one part can affect other parts.
Lesson 4: Environmental Change
Examine how changes in habitats affect plants and animals.
Learning goals
- Identify natural and human-caused environmental changes.
- Describe ways organisms may respond to habitat change.
- Evaluate a solution to a problem caused by environmental change.
Habitats can change
Habitats can change because of floods, droughts, fires, storms, construction, pollution, new organisms, or changes in food and water. A change may help some organisms and harm others.
Organisms respond in different ways
When a habitat changes, some organisms survive and reproduce, some move to new locations, some move into the changed environment, and some die.
Solutions can be compared
People can design solutions to reduce problems caused by environmental change. A useful claim about a solution should include evidence about how well it meets the goal and stays within limits.