Experiment Vocab

Question 0

Ordered variables

Answer 0

Non numerical data can be ranked on a scale (eg abundant, common, rare)

Question 1

Categorical variable

Answer 1

Values are described by labels or categories (eg eye colour)

Question 2

Discrete variable

Answer 2

Data that can only be whole numbers (eg number of children)

Question 3

Continuous variable

Answer 3

Variable that can have any numerical value (eg height)

Question 4

Independent variable

Answer 4

Variable that is changed by the researcher in an experiment

Question 5

Dependant variable

Answer 5

Variable that is measured by the researcher

Question 6

Control variable

Answer 6

Variable that is kept constant by the researcher

Question 7

Valid

Answer 7

An experiment that is controlled and had only one independent variable

Question 8

Reliable

Answer 8

An experiment with consistent results

Question 9

Accurate

Answer 9

Results are close to true value

Question 10

Precise

Answer 10

Data have a high degree of detail

Question 11

Why make an experiment valid, and how?

Answer 11

Why: changing other variables could affect the results
How: keep other variables constant (the same)

Question 12

Why make an experiment precise, and how?

Answer 12

Why: obtain a more accurate (closer to the true value) result
How: use an instrument that measures to a high degree of detail

Question 13

Why make an experiment reliable , and how?

Answer 13

How: repeat experiment, compare results with those of others
Why: repeating experiments helps you spot anomalous results and to obtain an average from the non-anomalous results

Question 14

How would you make an experiment accurate?

Answer 14

Use correct equipment and method for experiment (eg weighing scales that ate calibrated correctly)

Question 15

How can you test for heat production during respiration

Answer 15

Using germinating peas in vacuum flasks

Question 16

Control

Answer 16

A control experiment is when the independent variable (the one you do or change) is omitted from the experiment so you can compare the result to the experiment with the independent variable

Question 17

How to test for carbon dioxide during respiration

Answer 17

Turns limewater cloudy

Question 18

3 ways to demonstrate osmosis

Answer 18

Membrane bags
Potato tissue
Observing plant cells

Question 19

Test for starch

Answer 19

Reddish-brown iodine solution turns blue-black with starch

Question 20

Test for glucose

Answer 20

Blue benedict’s solution turns orange-red when heated

Question 21

Determine energy content of a food sample

Answer 21

Burn it and use it to heat a measured sample of water

Question 22

Why should you use a water bath to heat a test tube of water, rather than heating it directly in a Bunsen flame?

Answer 22

To avoid the heated liquid jumping out of the tube