Biology • Virtual Lab

Elodea Photosynthesis & Cellular Respiration Lab

Model a familiar classroom Elodea investigation. Change one variable at a time, make a prediction, run repeated trials, count oxygen bubbles, and connect observations to photosynthesis and cellular respiration.

Pre-lab check Digital lab alternative Repeated-trial data

Grades 9–12

Choose how students will use the model

Pre-Lab hides sensor/rate information so students focus on observable evidence. Digital Lab reveals the full system.

Elodea Experimental Chamber

Observe the cut sprig and the oxygen bubbles it produces.

System ready

Lamp

20 cm

Elodea sprig in water + dissolved CO₂ source

O₂ 8.00 mg/L

CO₂ 12.00 mg/L

Oxygen bubbles 0 this 5-min trial

                  cut end
                

Photosynthesis 0.00 relative rate

Cellular respiration 0.00 relative rate

Net O₂ effect Balanced O₂ change ≈ 0

Pre-Lab mode: Use the visible bubble count as your evidence. Sensor and rate data are intentionally hidden.

Experimental Setup

Change one variable at a time for a fair test.

Lamp distance 20 cm

10 cm ~47% relative light 50 cm

Lamp power Turn the lamp off to test darkness.

Light color White

Dissolved CO₂ availability 60%

LowHigh

Water temperature 25°C

5°C45°C

Prediction Compared with the control setup

Choose a prediction before running the trial.

Control setup

20 cm • white light • 60% dissolved CO₂ • 25°C. Repeat each setup at least three times before comparing averages.

1Choose one variableKeep the others controlled.

2Make a predictionMore, fewer, or similar bubbles?

3Run 3 trialsBiological data naturally vary.

4Compare averagesUse evidence to explain the pattern.

Trials at current setup 0 Repeat the exact conditions to build an average.

Average bubbles / 5 min — Complete at least 2 matching trials.

Average net O₂ effect — Shown in Digital Lab mode.

Live Rate Graph

Photosynthesis and cellular respiration during the current trial.

Photosynthesis Respiration

Trial Results

Repeated trials include small biological variation.

Trial	Prediction	Distance	Color	CO₂	Temp.	Bubbles	Photo.	Resp.	Net O₂
Run a trial to begin collecting data.

Connect the observation to the biology

Reveal this after students have collected evidence.

Download Investigation Worksheet