Which law states that each gas in a mixture exerts its own pressure and that these add up to the total?

1. Partial pressure is the pressure of a single type of gas in a mixture. 2. Dalton's law says a specific gas type in a mixture exerts its own pressure independently of the others. 3. It follows that the total pressure is the sum of all the partial pressures. 4. Boyle's law concerns volume and pressure in a single gas, so it answers a different question. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 22 "The Respiratory System", section 22.4 Gas Exchange_