Question

A scientist fills a glass container with water and places an aquatic plant inside the container, then closes the lid and places the container in direct sunlight. The scientist observes small bubbles on the surfaces of the plant’s leaves on days 1 and 2, but no bubbles on day 3. The scientist concludes that the bubbles were caused by photosynthesis. Which substance should be added to the water in order for the bubbles to reappear?(1 point)
Responses

carbon dioxide
carbon dioxide

oxygen
oxygen

glucose
glucose

hydrogen gas

Answer 1

carbon dioxide

Photosynthesis uses CO2 (and light and water) to make glucose and O2. In a closed jar CO2 becomes limiting, so adding CO2 lets photosynthesis resume and O2 bubbles reappear.