Great Question! <em>The function of DNA polymerase is to replicate, proofread and repair the DNA.</em>
Answer: the two tropics zones
Explanation:
Between the two tropics zones, which includes the equator, the Sun is directly overhead twice per year. Outside the tropic zones, whether to the south or north, the Sun is never directly overhead. Two other significant lines of latitude are the Arctic Circle (around the North Pole) and the Antarctic Circle (around the South Pole).
The immune system, and the excretory system
(Honestly, all of them work to keep us 'healthy', but I believe these are the ones you're looking for)
