Solve all the questions as soon as possible
I am answering first three questions here, for remaining questions please ask seperately in different thread.
1) Cartilaginous rings are horizontally arranged C shaped bands of cartilage and their basic function is to provide support and to prevent the collapse of trachea during inspiration.
2)The epiglottis is a small flap that prevents food from entering the trachea.
3) Respiratory pigments are specialised pigments present in the blood that aid in the transportation of respiratory gases from the lungs to different parts of the body. For example, Haemoglobin is a red-coloured respiratory pigment that transports oxygen in humans.
Hope this answers your query,
Apart from oxygen transportation, hemoglobin has some role in transportation of carbon dioxide from body parts to lungs. About 10% of carbon dioxide transportation occurs through hemoglobin.