Why did the petri dish get warm when hydrogen peroxide and liver were combined?

Answer: The bubbles will form due to the liberation of oxygen gas and white spots will develop on the liver.

Explanation:

The liver is a vital organ, its function is to metabolize the toxins into less harmful metabolites, that are excreted out of the body.

The catalase is one of the enzymes that participate in the metabolic activities of the liver. In the given condition, when hydrogen peroxide and liver were combined. The catalase enzyme breaks down the hydrogen peroxide into water and oxygen. In this reaction, the oxygen gas is liberated, in the form of bubbles and this reaction produces white colored foam which later leaves white spots on the liver.