Biology is the study of life, and uses the scientific method, the basis of science, to do so. Hypotheses are made, tested, and remade, until a theory is made, which then becomes Scientific law.
Answer:
well, I'm no college student but using common sense you need more than one so when one fails the other can come in and hopefully succeed.
Explanation:
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).