I think the correct answer from the choices listed above is option A. Sickle cell disease is caused by a change in allele. It is a disorder of the blood caused by an inherited abnormal hemoglobin. Hope this answers the question. Have a nice day.
Cellular respiration is the metabolic process by which a cell produces usable energy in the form of ATP. In order to accomplish this cells require Glucose and Oxygen to form the reaction which produces ATP and the byproducts of Water and CO2.
In reality its a complex topic however this is the basic form.
Reflex action in the diagram would be the response. Diagram extracted from online.