If it has a nucleus or not
As heart rate increases, blood pumps faster through your body and you start to have better reflexes. You brain sends out signals to your legs. This can be an example of the flight or fight response. Your leg and arm muscles tighten up, blood is decreasing from lesser needed spots such as your chest, back, and head areas.
Answer:
haemoglobin
Explanation:
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body
This is true. it is called origin.
