Gaseous Exchange swapping Oxygen and Carbon Dioxide. Tissue Respiration, Ventilating the Lungs and Gaseous Exchange are terms with precise meanings and you must know what these are. Tissue respiration is the release of energy, usually from glucose, in the tissues of all animals, green plants, fungi and bacteria. All these living things require energy for other processes such as growth, movement, sensitivity, and reproduction. When oxygen is not available, some organisms can respire anaerobically i.e. without air or oxygen.
Yeast can respire in both ways.
Yeast gets more energy from aerobic respiration, but when it runs out of oxygen it does not die. It can continue to respire anaerobically, but it does not get so much energy from the sugar. We can respire in both ways too. Normally we use oxygen, but when we are running in a race, we may not get enough oxygen into our blood, so our muscles start to respire anaerobically. Unlike yeast we produce lactic acid.