Photosynthesis Pondweed Lab

Plants make their own food by photosynthesis: using light energy, the chlorophyll in their chloroplasts turns carbon dioxide and water into glucose and gives off oxygen. In this lab a sprig of pondweed under a lamp releases oxygen bubbles that students can count, so moving the lamp, adding carbon dioxide or changing the temperature shows which limiting factor sets the rate. Students can change lamp distance and carbon dioxide and compare what happens. Use it for biology inquiry with Grades 3–5, Middle School, and High School on a projector or student device.

ស្តង់ដារ៖ NGSS MS-LS1-6, 5-LS1-1

• Move the lamp closer and count more oxygen bubbles, then find where extra light stops helping
• Record results and build a graph of the rate against light, carbon dioxide or temperature
• Change a second factor and start a new line: a fair test that reveals the limiting factor
• Try red, blue and green light and discover why leaves look green
• Zoom in to the leaf cells and a chloroplast to see where the oxygen and sugar are made

1. 1Predict how changing lamp distance will affect the oxygen bubbles per minute, then test the prediction.
2. 2Use evidence from the interactive visual to explain the result.

សំណួរដែលគ្រូតែងសួរ