How Scientists Work

Question 1

How do scientists work?

Answer 1

Using the scientific method

Question 2

What are the steps in the scientific method in order?

Answer 2

1. Make an observation
2. Ask a question
3. Test with an experiment
4. Record and analyze results
5. Draw a conclusion

Question 3

What do scientific experiments do?

Answer 3

Only support or refute/challenge hypothesis, not prove things.

Question 4

What is a variable?

Answer 4

Something that can change
Ex: the temperature of a room

Question 5

What is a controlled experiment?

Answer 5

A scientific test where only one variable, the manipulated variable, is changed

Question 6

What is a hypothesis?

Answer 6

An educated guess based on an observation and previous knowledge that is testable

Question 7

What is a controlled variable?

Answer 7

An element in a scientific experiment that remains the same throughout the investigation.

Question 8

What is a manipulated variable?

Answer 8

Also know as an independent variable, a factor that is deliberately changed in a scientific investigation

Question 9

What is a responding variable?

Answer 9

An element that changes in response to the manipulated variable

Question 10

What is spontaneous generation?

Answer 10

Also known as abiogenesis, the idea that life could come from non living matter

Question 11

What did Francesco Redi propose?

Answer 11

That maggots come from eggs laid by flies on meat

Question 12

What was Redi’s observation?

Answer 12

Flies land on meat that is uncovered. Later, maggots appear on the meat

Question 13

What was Redi’s hypothesis?

Answer 13

Flies produce maggots

Question 14

What was the manipulated variable in Redi’s experiment?

Answer 14

The gauze covering that keeps flies away from meat

Question 15

What was the responding variable in Redi’s experiment?

Answer 15

Whether maggots appear

Question 16

What was Redi’s conclusion?

Answer 16

Maggots form only when flies come into contact with meat. Spontaneous generation did not happen

Question 17

Why do scientists record data?

Answer 17

So that the experiment can be repeated

Question 18

Why do scientists repeat experiments?

Answer 18

To ensure that the results match the previous and are consistent

Question 19

Who challenged Redi’s results and what did he claim?

Answer 19

Needham, who claimed that spontaneous generation was possible under the right conditions

Question 20

What did Needham do?

Answer 20

Sealed a bottle of gravy and heated it

Question 21

What were Needham’s results?

Answer 21

After several days, the gravy was filled with microorganisms

Question 22

What did Needham conclude from his experiment?

Answer 22

That the microorganisms came from spontaneous generation

Question 23

What did Spallanzani do as a test?

Answer 23

Boiled the gravy, and kept the flask open and the other sealed

Question 24

What were Spallanzani’s results?

Answer 24

The open flask was filled with microorganisms, and the sealed one was not

Question 25

What did Spallanzani find?

Answer 25

If the gravy was boiled and sealed, no microorganisms would appear

Question 26

What did Needham do wrong?

Answer 26

Not heat the gravy enough

Question 27

What was Louis Pasteur's experiment?

Answer 27

First, he boiled broth. After a year, the broth had no microorganisms, however, once he removed the curved neck, the broth was filled with them

Question 28

What did Pasteur do differently than Spallanzani?

Answer 28

He used a swan neck flask

Question 29

What did Pasteur show?

Answer 29

That spontaneous generation was not possible, even if air was available

Question 30

When are two cases where experiments not possible?

Answer 30

1. Wild animals must be observed without disturbing them 2. Ethical considerations prevent some experiments

Question 31

What do scientists do if an experiment isn't possible?

Answer 31

They plan alternate investigations, which they can use to discover reliable patterns that add to scientific understanding

Question 32

What is a theory?

Answer 32

A well tested hypothesis that is very well supported by experiments

Question 33

Is a theory the absolute truth?

Answer 33

No

Question 34

When new evidence is uncovered, what happens to a theory?

Answer 34

It is revised or replaced