1-2 How Scientists Work.................................................................. Name ___________________________________

1. Aristotle made extensive observations about the ________________________________
2. According to the "Recipe for Bees" what did you have to kill during the winter? ___________
3. What is spontaneous generation? ______________________________________________
4. What was Redi's hypothesis? _______________________________________________
5. The factors in an experiment that can change are called ____________________________
6. A hypothesis should be tested by an _____________________________ in which only one _________________________ is changed at a time.
7. The variable that is changed is called the __________________________ variable.
The variable that is not changed is called the _________________________ variable.
8. In the image below, which jar (X or Y) would have developed maggots? _____________

9. What was the purpose of the gauze in the experiment? ________________________
10. Which of the jars above was the control jar? ____________________
11. In the past, data was often recorded in notebooks or personal _________________. Today, researchers often store their data on a ___________________________.
12. Scientists use data to draw a valid __________________________________
13. Redi's results explained where ______________________ come from.
Redi's results refuted the hypothesis of ________________________________________

14. Number the following steps in the correct order.

_________ Forming a hypothesis
_________ Drawing a conclusion
__________ Recording and analyzing results
__________ Asking a question
__________Setting up a controlled experiment

15. Scientists publish their results in journals in order to: a) get paid b) allow other scientists to check their work
16. What did Anton van Leeuwenhoek call the tiny moving objects he saw in water? ___________________________
17. John Needham attempted to show that "little animals" could come from ____________________________
18. Spallanzani's experiment showed that the living things that entered the gravy came from where? _______________

19. Pasteur improved on on Needham's experiment by :
a) leaving the flask open to the air b) sealing the flask c) adding water to the flask

20. Name the scientist credited with the discovery:

1. Blood is circulated through vessels ______________________________
2. Anthrax vaccine _____________________________________
3. The structure of DNA (two people) ______________________________________
4. Detailed study of human anatomy _______________________________________

21. Name one reason why a controlled experiment may not be possible: _________________________________
22. If a hypothesis becomes very well supported, scientists may consider it a ______________
23. In science, the word _____________, applies to a well tested explanation that unifies a broad range of___________.
24. What two theories help explain why some marsupial mammals are only found in Australia?
25. What can happen to a theory if new evidence is found?_________________________________________