Aldosterone is secreted in response to changes in
C. blood pressure
The pneumatic bones are important to birds for respiration. They are hollow bones which are connected to the bird's respiratory system and are important for birds to be able to breath. Examples of pneumatic bones are the skull, humerus, clavicle, keel (sternum), pelvic girdle, and the lumbar and sacral vertebrae.
Glucagon is the hormone that helps in restoring the levels of blood glucose levels. It is produced by alpha cells of the pancreas. It stimulates the liver to break the glycogen, so that they may be utilized by the body, as a source of energy. It also stimulates glucose synthesis in the body.
Answer:
B,the variable that is changed and being tested
