Module 1: Practical Skills In Biology ⚪️

Question 1

How to plan a valid method

Answer 1

1. Select the most appropriate apparatus
2. Outline the exact techniques of how to use the apparatus
3. Identify the IV and control variables
4. Have a suitable control experiment to demonstrate that only the IV is causing any change to the results

Question 2

Syringe

Answer 2

• used for measuring small volumes
• it is more accurate and precise than a measuring cylinder
• has a higher resolution and will therefore result in a lower percentage uncertainty

Question 3

Uncertainty

Answer 3

To work out uncertainty you must find the smallest increment of measurement on your
measurement device and then divide it by two

Question 4

Quantitative observations

Answer 4

• numerical

Question 5

Independent variable

Answer 5

The only value that should be “changed”throughout the experiment

Question 5

Qualitative observations

Answer 5

• descriptions
  e.g. colours

Question 5

Precision

Answer 5

• How close the agreement is between several measured values
• You can only determine if your results are precise by repeating the
  measurement
  -Reducing the effect of random errors improves precision.

Question 6

Accuracy

Answer 6

How close a reading is to the true value

Question 7

Dependent variable

Answer 7

This is the variable that is measured to determine the result of the experiment

Question 8

Control variable

Answer 8

Any values that affect the result of your experiment should be controlled or monitored

Question 9

Mean

Answer 9

• A measure of the average
  The sum of all the values divided by
  the number of values in the data set

Question 10

Median

Answer 10

• a measure of the average
• the middle value when the data is ranked

Question 11

Mode

Answer 11

• a measure of the average
• the value that occurs most often in a data set

Question 12

Standard deviation

Answer 12

Measures the spread of data around the mean value
- very useful when comparing consistency between different data sets

Question 13

Anomaly

Answer 13

An outlier in a set of results

Question 14

Analysing results

Answer 14

• observe
• record
• process data
• plot suitable graph

Question 15

Processing data

Answer 15

• this includes calculating the mean,median or mode
• it can also include calculating the standard deviation and statistics
• from this , the results can be interpreted

Question 16

Plotting a graph

Answer 16

-Select the correct data for each axis
-Use an appropriate scale
-Lable both axis and include units
-Draw an accurate line of best fit
- (curved or straight) if appropriate

Question 17

Evaluating data

Answer 17

Identifying patterns in data that do or do not fit suggested conclusions

Question 18

Methods of evaluating data

Answer 18

Are there any anomalies?
Does the method have limitations?
Was the practical technique precise and accurate?
Is there information on percentage error or uncertainties?
Is there a standard deviation or
statistic?

Question 19

Suggesting improvements to methods

Answer 19

Review the method and look for changes to equipment or techniques that could result in more accurate data

For example: more repeats , ensuring no bias

Question 20

Control experiment

Answer 20

• A test conducted exactly the same as the test experiment, but with the factor causing the change removed
• Used to compare data
• Used to prove any changes are due to the independent variable

Question 21

How is mass measured ?

Answer 21

Balance / scales

Question 22

How is time measured ?

Answer 22

Stop clock /watch

Question 23

How is temperature measured ?

Answer 23

Thermometer or data logger

Question 24

How is volume measured

Answer 24

Syringe , measuring cylinder, gas syringe

Question 25

How is length measured ?

Answer 25

Ruler or tape measure

Question 26

How is pH measured ?

Answer 26

Indicator paper , indicator solution , data logger

Question 27

Risk assessment

Answer 27

What could harm you? E.g. acid What harm could it cause you? E.g. corrosive to skin and eyes What actions could be put in place to prevent/ treat this? E.g. wear goggles and a lab coat

Question 28

Research

Answer 28

- Sources must be reliable and trustworthy - important in planning valid experiments that will produce accurate results

Question 29

Reliable sources

Answer 29

- A source that provides a thorough, well-reasoned theory, argument or discussion based on strong evidence - To ensure a source you are using is reliable, look at the author's information and publication data

Question 30

Colorimeter

Answer 30

- Measures light absorbance (how much light is absorbed) or light transmission (how much light passes through) a substance - Colorimetry can be used in any enzyme-catalysed reaction that involves colour change

Question 31

Potometer

Answer 31

A piece of apparatus designed to measure water uptake in a leafy shoot This is used as a measure of transpiration