Final answer:
The filter paper disks soaked in catalase solution floated due to the production of oxygen gas from the breakdown of hydrogen peroxide, which decreased the density of the disks and made them buoyant.
Step-by-step explanation:
Jenny soaked filter paper disks in a catalase solution, and after 30 seconds, the disks floated to the surface. This occurrence is best explained by the production of oxygen gas. When the filter paper disks are added to the catalase solution, any hydrogen peroxide present is broken down by the catalase enzyme into water and oxygen. The release of oxygen gas creates bubbles that adhere to the surface of the disks, decreasing their density and causing them to rise to the surface due to the buoyant force exceeding the force of gravity. This activity is an application of the catalase test, which uses the presence of bubbling to determine if aerobic bacteria are capable of breaking down hydrogen peroxide.