Would a light source be considered an internal or external stimulus? Explain your answer.

Which plains area lies in both the united states and canada? altiplano central canadian shield coastal plains great plains

How had the study of mitosis affected scientists knowledge of cancer

An example of internal feedback working to maintain homeostasis is your a. decreased respiration rate when you are studying b. decreased heart rate when you are sad c. increased respiration rate when your muscles need more oxygen d. increased heart rate when your lungs need more oxygen