7. Mammals have a double circulatory system Blood flows between
the heart and the lungs
the heart and the rest of the body (systemic circulation),
(a) Fig. 7.1 shows a cross-section of an artery.
Fig. 7.1
Explain how the structure of an artery, as shown in Fig. 7.1. is related to its functions.

Flock x flock y flock z total pieces of food eaten (from previous page) 147 93 60 food percentage* % % % simulated number of birds in flock for 3rd generation** * divide each flock's total pieces of food by 300, the total number of pieces of food eaten. ** multiply the food percentage for each flock by the total number of birds (30).

When analyzing tree rings, what do scientists assume a thin ring indicates?

Which food could be transported in a galvanized metal container?