Which product of respiration is considered waste material and leaves the alveoli

When oxygen travels to the body via red blood cells, after the oxygen has been distributed to cells, the haemoglobin picks up a waste product called carbon dioxide (CO2) and exposes of the waste by exhaling it via the alveoli

Answer;

Carbon dioxide

Explanation;Cellular respiration is the process that takes place in the cell where glucose is broken down in presence of oxygen through three phases to yield energy in the form of ATP, and carbon dioxide and water as byproducts.In this process carbon dioxide is produced as a waste product.Glucose + oxygen → water + carbon dioxide The carbon dioxide released fro respiration dissolves in the blood plasma, and must be removed to avoid very high blood acidity. The blood flows through the lungs where carbon dioxide is removed from the blood to the alveoli by diffusion and then exhaled out of the body.

Since we don't see a strand; i got answers off a sheet and the correct answer is "2".