Q1. The gas ______ is transported into the red blood cells. This is carried on a molecule termed as ______ found in the RBC’s. There are around 250 million ______ molecules in each RBC. Each can carry ______ oxygen molecules. The gas ______ is mainly carried in the ______ of the blood rather than in the RBCs. It combines with water in the blood to generate carbonic acid which quickly modifies chemically to ______, a safe way to carry the gas in blood. When the ______ reaches the lungs, it is converted back to ______ gas, which then diffuses out of blood and is exhaled.
Q2. The main factors which influence respiratory rate and depth are ______ such as talking or coughing, ______ (for illustration, sometimes we try to breath at a different pace to relax), ______ like being scared, and ______ such as the amount of ______ or ______ in the blood.