practical skills: written assessment

Question 1

preliminary research

Answer 1

Planning is an essential part of experimental biology

Preliminary research can be very helpful when trying to design an experiment to investigate a particular theory or hypothesis
Preliminary means “to come before”

Question 2

Researching other similar studies or experiments can help you with

Answer 2

Choosing the appropriate apparatus

Using the correct techniques

Identifying variables

Controlling other variables

Recording and collecting data accurately

Processing and presenting data in a useful way

Question 3

The choice of apparatus and techniques

Answer 3

The choice of apparatus and techniques should be based on the science surrounding the issue being investigated

For example, when testing the effect of different pH levels on enzyme activity is crucial that you know:

How to quantify/measure enzyme activity accurately

What other conditions (variables) will affect the function of an enzyme

For example, if the temperature becomes too high all the enzymes will denature and the enzyme activity will be 0 (no matter what the pH level is)

Question 4

preliminary studies

Answer 4

Once the preliminary research has been completed then preliminary studies can be conducted to further aid the experimental design

These studies are very important for:
Identifying additional variables that affect the experiment

Finding the best way to control these variables

Deciding on the quantities and volumes of substances that are needed so that you do not run out of reactants/reagents

Any experiment conducted without preliminary research or studies is likely to be invalid as the other variables that affect the results in the experiment will not have been identified and controlled

Question 5

types of variables

Answer 5

In an experiment, a variable is any factor that could change or be changed

There are different types of variables within an experiment

The independent variable: the only variable that should be changed throughout an experiment

The controlled/confounding variables: any other variables that may affect the results of the experiment that need to be controlled or monitored

The dependent variable: the variable that is measured to determine the outcome of an experiment (the results)

Question 6

validity of variables

Answer 6

It is essential that any variable that may affect the outcome of an experiment is controlled in order for the results to be valid

Preliminary research and preliminary studies can be used to identify variables within an experiment and to determine ways of controlling these variables effectively

The science surrounding the issue/problem being investigated is likely to contain information about different factors or variables that may exist