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Science Review

Grade 4 · Stretch challenge · 10 questions · Version PG-P7VEFH-DBMY

1.

How do greenhouse gases warm Earth?

2.

What is the role of chlorophyll?

3.

What is density?

4.

What is the difference between weather and climate?

5.

What transfers traits from parents to offspring?

6.

Why are food webs more realistic than single food chains?

7.

What cell structure contains genetic material?

8.

Which layer of Earth is liquid iron and nickel?

9.

State Newton's third-law force pair when swimming.

10.

Why does salt lower water's freezing point?

Answers and teaching notes

Use the answers to check the work after the learner finishes. For writing prompts, the guide describes what a strong response should include.

Show answers for version 17
  1. How do greenhouse gases warm Earth?They absorb and re-emit infrared energy
  2. What is the role of chlorophyll?Absorb light for photosynthesis
  3. What is density?Mass per unit volume
  4. What is the difference between weather and climate?Weather is short-term; climate is long-term patterns
  5. What transfers traits from parents to offspring?Genes
  6. Why are food webs more realistic than single food chains?Organisms have multiple food sources and predators
  7. What cell structure contains genetic material?The nucleus
  8. Which layer of Earth is liquid iron and nickel?Outer core
  9. State Newton's third-law force pair when swimming.Push water back; water pushes swimmer forward
  10. Why does salt lower water's freezing point?It disrupts ice crystal formation

Worked example

Connect the question to an observable process or scientific model.

Common mistake

Selecting a familiar term without checking its meaning.

Helpful hint

Explain why your answer makes sense.