Science · Unit 3 · Weeks 13–18
Life Cycles & Living Together
The big idea
Your child builds an argument with evidence that living in a group, such as a wolf pack or a honeybee colony, helps some animals survive. Then your child compares the life cycles of a bean plant, a butterfly and a frog and sees that all living things are born, grow, reproduce and die. The unit ends with field study of a small local ecosystem and a model that predicts what happens when the environment changes.
Standards in plain words
- 3-LS2-1 Argues from evidence that some animals form groups that help members survive.
- 3-LS1-1 Makes models showing that living things have different life cycles, but all are born, grow, reproduce and die.
- 3-LS4-3 Argues from evidence that in a given habitat some living things survive well, some survive less well and some cannot survive at all.
- 3-LS4-4 Judges how well a solution works for a problem caused when an environment changes and the plants and animals living there may change.
- 3-LS4-2 Uses evidence to explain how differences among individuals of the same kind can help some survive, find mates and have young.
What mastery looks like
- Makes a claim about group living and supports it with a fact, such as how a herd protects its members.
- Puts the stages of a plant, butterfly and frog life cycle in order and names what they share.
- Records the living and nonliving things in a study square and notices patterns across visits.
- Builds an ecosystem model with producers, consumers, decomposers and nonliving parts and draws energy arrows.
- Predicts how a change, such as losing a pond, affects the model and judges a solution and its limits.
Materials
- Pictures of animal groups (wolf pack, honeybee colony, herd of elephants)
- Dry bean seeds, a clear cup and potting soil
- Magnifying glass
- Clipboard or hardcover book for field notes
- Shoebox or tray for an ecosystem model
- Paper plates and index cards for sorting
- Science notebook
Anchor texts
- Reading About Our World passages: 'Better Together' (Week 13), 'Who Eats Whom?' (Week 14), 'Changing as They Grow' (Week 15) and 'A Bridge for Animals' (Week 17)
- Video hub topics: why some animals live in groups, the plant life cycle, choosing a local ecosystem to study, and planning a model ecosystem
Watch across the unit
Watch for: Thinking the queen bee is the boss, or that animals in a group are always safe.
Try: Explain that the queen's main job is laying eggs, and that groups lower the risk but predators still catch some animals.
Watch for: Believing small butterflies are babies, or that a butterfly comes out of a cocoon.
Try: Explain that adult insects do not grow; the caterpillar does all the growing, and butterflies form a chrysalis while moths spin cocoons.
Watch for: Thinking a model is exactly the same as the real ecosystem.
Try: Ask, 'What does the real ecosystem have that your model does not?' and list at least two differences.
Pacing
Short week: Plant the bean on the Week 15 Monday even in a short week, since it is observed for weeks. In the field-study week, keep at least two visits to the study square. Otherwise keep Monday's lesson and the Friday check.
Flex week: Week 14 is the flex week. Catch up on food chain arrows and adaptations, or enrich with a camouflage color investigation and a fair test of which conditions pill bugs choose (then return them outdoors). End with the Weeks 10 to 13 review.
Week by week
| Week | Topic | Investigation |
|---|---|---|
| Week 13 | Animal groups | Compare group-living animals |
| Week 14 | Flex week | Choice investigation |
| Week 15 | Life cycles | Compare plant, butterfly and frog life cycles |
| Week 16 | Studying a local ecosystem | Observe and record a local ecosystem |
| Week 17 | Modeling an ecosystem | Build a model and predict changes |
| Week 18 | Quarter 2 review | Performance task; Unit 3 test |