Plant Light Experiment

Overview

Today students will learn how to plan and run a simple investigation using the practice of designing experiments, forming hypotheses, collecting data, and analyzing results. They will focus on a real-world question: whether plants grow faster under different colors of light.

Learning intentions

Students will be able to:

• Identify the difference between a hypothesis and a scientific question.
• Design an experiment to test how plant growth changes with different colors of light.
• Collect accurate quantitative data (e.g., height change over time) and record it clearly.
• Analyze data to determine whether results support a hypothesis.

Success criteria

Students can:

• Write a testable hypothesis that matches the investigation question.
• Create a simple experimental plan that controls key variables and identifies the independent and dependent variables.
• Collect and organize data in a table and graph (at least one visual representation).
• Explain whether the data supports the hypothesis and cite evidence from their results.

Curriculum links

• Inquiry and designing investigations in science (asking questions, planning procedures, controlling variables, using measurements).
• Scientific practices: developing and using models, using mathematics and data, and constructing explanations with evidence.
• Nature of science: how scientific knowledge develops through questioning, evidence, and iteration.
• Crosscutting concepts: cause and effect and using patterns in data to support claims.

Lesson structure (25 minutes)

1. 0–3 min | Engage and question

• Show a short prompt: “Do plants grow faster under red, blue, or white light?” Ask students to quickly discuss: what would you need to change and what would you measure?
• Clarify that a scientific question can be answered with evidence, and today they will gather that evidence.

2. 3–7 min | Hypothesis and variables

• Model writing a hypothesis using an if/then structure tied to light color (independent variable) and plant growth (dependent variable).
• Have students identify: what stays the same (controlled variables like water amount, plant type, soil amount, and total light exposure time).

3. 7–10 min | Experiment design walkthrough

• Provide a “mini-lab plan” template on the board: materials, procedure steps, variable controls, and measurement method.
• Teacher demonstrates how to measure plant height consistently (same starting point, same ruler position, same time of day).

4. 10–17 min | Data collection setup + recording

• Students work in groups of 3–5. If you have live materials, students measure and record current height for each light condition; if not, provide pre-made data sets from a prior run or simulated results.
• Students record data in a class-friendly table (light color, starting height, ending height, height change). Emphasize accuracy and legibility.

5. 17–22 min | Graphing and analyzing patterns

• Students create a simple bar graph or line plot of average height change for each color of light.
• Prompt them to look for patterns and answer: Which color shows the greatest growth? Do the data match the hypothesis expectation?

6. 22–25 min | Evidence-based claim

• Each group writes a short “claim-evidence-reasoning” statement: whether the data supports or does not support the hypothesis, using their graph/table as evidence.
• Quick share: 2–3 groups read their conclusions.

Resources

• Student data table worksheet (starting height, ending height, height change)
• Simple graphing paper or a one-page digital graph template (teacher-provided)
• Rulers (cm), measuring cups, labeled containers (if using real plants)
• Light-color materials (LED lamps or colored filters) OR teacher-provided pre-collected/simulated data
• Hypothesis sentence stems (e.g., “If plants get ___ light, then they will grow ___ because ___.”)
• Group roles card (Materials Manager, Data Recorder, Graph Checker)
• Timer for consistent measurement interval
• Dyslexia-friendly printed options (high-contrast worksheets, reduced text, larger fonts)

Assessment

• Formative: teacher observes group variable identification and checks hypotheses for testability and alignment to the question.
• Formative: review completed data tables and the correctness of the graph scale/labels.
• Summative (exit): students submit a brief claim-evidence-reasoning response stating whether results support the hypothesis.

Differentiation

• Support:
• Provide a partially filled-in variable chart (independent, dependent, controls).
• Use sentence starters for hypotheses and CER writing.
• Offer a “checklist” for experiment design: testable question, controlled variables, clear measurement.
• Extension:
• Challenge advanced students to propose an additional test (e.g., different light intensity) while keeping all other variables controlled.
• Ask them to calculate and compare averages and percent change, then discuss reliability (replication).
• EAL/SEN:
• Pre-teach essential terms using visuals (arrow diagram: independent → dependent; controls stay the same).
• Reduce reading load by using shorter procedure cards with large icons and step numbers.
• Allow oral responses recorded by a peer scribe for CER.
• Dyslexia-friendly reading options:
• Provide worksheets in large font, minimal text, and high contrast.
• Offer an audio version of the directions/procedure (teacher reads aloud) and allow students to follow along with a blank “fill-in” format.