In the experimental set-up, the rubber sheet represents the organ called

The rubber sheet in the experimental set-up represents the diaphragm. The diaphragm is a dome-shaped muscle located at the bottom of the chest cavity. When it contracts, it moves downward and flattens out, increasing the volume of the chest cavity and causing air to be drawn into the lungs. When it relaxes, it moves back up into its dome shape, decreasing the volume of the chest cavity and causing air to be pushed out of the lungs. In the experimental set-up, the rubber sheet is used to simulate the movement of the diaphragm. As the rubber sheet is pulled downward, it increases the volume of the jar, creating a vacuum that draws the egg inside. This represents the movement of the diaphragm during inhalation, which increases the volume of the chest cavity and draws air into the lungs. Therefore, the rubber sheet in the experimental set-up represents the diaphragm.