Im not writing your essay but some plants are used as medication and other remedies. plants are important because they provide food, medicine, oxygen, etc.
The events of inspiration begins with the;
Impulses are conducted on the phrenic nerve to muscle fibers in the diaphragm contracting them.
As the dome shaped diaphragm moves downward the thoracic cavity expands.
At the same time the external intercostal muscles may contract raising the ribs and expanding the thoracic cavity further.
The intra-alveolar pressure decreases
Atmospheric pressure greater than intra-alveolar pressure forces the air into the respiratory tract through the air passages.
The lungs fill with air.
Air enters into the body through nose and proceeds to pharynx or windpipe afterwards it proceeds down and reaches to larynx the voice box and continue to proceed to trachea which is surrounded by rings so that by air pressure it cannot be collapse from there a divides into two side left and right bronchus then it conducted towards bronchioles which is the pathway to alveoli at last it reaches to its Final Destination (not that movie....hahah) which is alveoli where the exchange of gases takes place