Why are aquatic plants such as Elodea suitable for investigating photosynthesis?

Why are aquatic plants such as Elodea suitable for investigating photosynthesis?

• A. Bubbles of oxygen visible for counting
• B. They store more starch
• C. They require no light
• D. They have no chloroplasts

Answer: (A)

Oxygen produced during photosynthesis is the visible, direct signal you can use in a simple aquatic experiment. In Elodea, when light is present, the plant’s chloroplasts drive the reactions that split water, releasing oxygen. That gas forms bubbles that rise in the water, so you can see and count them to gauge how fast photosynthesis is happening under those conditions. This makes Elodea especially convenient: its submerged leaves reveal bubbles clearly, so the rate can be estimated without fancy equipment, just by observing the gas coming off. The idea isn’t about starch storage or anything that happens after photosynthesis; it’s about real-time gas production. It also hinges on light because photosynthesis requires it, and the plant must have chloroplasts to perform the reactions that generate oxygen. So the visible bubbles are a simple, reliable proxy for photosynthetic activity in this setup.

Oxygen produced during photosynthesis is the visible, direct signal you can use in a simple aquatic experiment. In Elodea, when light is present, the plant’s chloroplasts drive the reactions that split water, releasing oxygen. That gas forms bubbles that rise in the water, so you can see and count them to gauge how fast photosynthesis is happening under those conditions. This makes Elodea especially convenient: its submerged leaves reveal bubbles clearly, so the rate can be estimated without fancy equipment, just by observing the gas coming off.

The idea isn’t about starch storage or anything that happens after photosynthesis; it’s about real-time gas production. It also hinges on light because photosynthesis requires it, and the plant must have chloroplasts to perform the reactions that generate oxygen. So the visible bubbles are a simple, reliable proxy for photosynthetic activity in this setup.