What is a hypothesis? How is it different from a guess? What is a theory?

Answer the following question 

1. What is a hypothesis? How is it different from a guess? What is a theory? (2 points)
2. List three different examples that provide evidence in support of evolution and justify briefly your choices (1 point)
3. Define homologous structure; provide an example to illustrate your definition. (1 point)
4. What is the difference between genetic drift and gene flow? (1 point)