Unit Plan 11 (Grade 5 Science): Plants: Inputs & Growth

Focus: Support an argument that plants get the materials they need for growth chiefly from air and water, not from “used-up soil” or “food from the outside.”

Grade Level: 5

Subject Area: Science (Life Science • Physical Science Connections)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students investigate the question: Where does a plant’s mass come from as it grows? They explore common ideas (plants “eat” soil, fertilizer, or just water) and compare these to evidence from observations, models, and data. Through demonstrations, readings, and simple investigations, students learn that plants take in water through roots and gases from the air (like carbon dioxide) through leaves, and that these inputs are rearranged into plant matter (stems, leaves, roots). By the end of the week, students construct and share an argument that plants get materials for growth chiefly from air and water.

Essential Questions

• Where do plants get the materials they need to grow larger and heavier?
• How do air and water become part of a plant’s mass (stems, leaves, roots)?
• What evidence can we use to support an argument about what plants need for growth?
• Why might people think plants get their mass from soil, and how can we use science evidence to check that idea?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Describe, using words and diagrams, that plants take in water through their roots and gases from the air (such as carbon dioxide) through their leaves.
2. Interpret observations or data (e.g., soil mass change, plant mass change, condensation in closed systems) that show that plants’ growth cannot be explained by soil loss alone.
3. Develop a model that shows inputs (air, water, and light energy) and outputs (plant matter, oxygen) for a growing plant.
4. Use evidence from investigations, models, or texts to support a written or oral argument that plants get the materials they need for growth chiefly from air and water.
5. Create a short CER (Claim–Evidence–Reasoning) explanation or mini-poster that clearly communicates how air and water become part of a plant’s body.

Standards Alignment — 5th Grade (NGSS-Aligned)

• 5-LS1-1 — Support an argument that plants get the materials they need for growth chiefly from air and water.

Success Criteria — Student Language

• I can explain that plants take in water through roots and gases from the air through leaves.
• I can use data or observations (like soil and plant measurements) as evidence in my argument.
• I can draw or use a model with arrows that shows air and water going into a plant and plant matter increasing.
• I can write or say a claim that plants get materials they need for growth mostly from air and water, and support it with evidence and reasoning.