Question 1
All mammals have a double circulatory system. Fig. 1.1 shows part of the human double circulatory system.

Fig. 1.1
Question 1(b)
Question 1(b)(i)
Describe what is meant by the term double circulation.
Question 1(b)(ii)
State one advantage of a double circulation.
Question 1(d)
Describe how blood is transported from the vena cava to the lungs. You may use the letters on Fig. 1.1 in your description.











