Introduction to Biology

Question 1

What are the four types of variables?

Answer 1

Independent variable, Dependent variable, Controlled variables, Confounding (hidden) variables

Question 2

Independent variable

Answer 2

A factor you can change (presence or absence of caffeine)

Question 3

Dependent variable

Answer 3

The factor you measure in response to change (number of words recalled)

Question 4

Controlled variables

Answer 4

Factors that might influence the results that you have some control over (caffeine source and amount)

Question 5

Confounding (hidden) variables

Answer 5

Hidden factors that may influence the results - we have no control over them (time of day, caffeine sensivity)

Question 6

Range of data

Answer 6

Max. data - min. data = Range of data
Only calculate if you have less than five values

Question 7

Standard deviation

Answer 7

Good to calculate if there is a lot of data, so more than five. Use a calculator to calculate it for you.

Question 8

Scatter Graph

Answer 8

Used to present data with a lot of errors and outliers. Useful for determining the relationship between two variables

Question 9

Outlier

Answer 9

A data value that lies outside the main spread of data

Question 10

Line Graph

Answer 10

Used when one variable affects another.

Question 11

Line Graph with measure of spread

Answer 11

The points are drawn with error bars

Question 12

Line Graph: Two Curves Plotted together

Answer 12

Useful when you need to compare two data sets together

Question 13

Bar Graph

Answer 13

The data are discontinuous, so the bars do not touch

Question 14

Histograms

Answer 14

Plots of continous data, usually of some physical variable against frequency of occurence

Question 15

Pie Graph

Answer 15

Good for showing relative proportions and for data sets with small number of categories