1 In an experiment investigating the effect of one variable on another, the independent variable is the one that you change and the dependent variable is the one that you measure. All other variables should be controlled (kept constant). 2 The range of the independent variable is the spread from lowest to highest...

One of the questions in the exam is likely to involve drawing a specimen on a slide, using a microscope, or drawing from a photomicrograph (a photograph taking through a microscope).Making decisions about what to drawYou might have to decide which part of a micrograph to draw. For example, there might be a micrograph of...

It is very important to understand the difference between experimental errors and 'mistakes'. A mistake is something that you do incorrectly, such as misreading the scale on a thermometer, or taking a reading at the wrong time, or not emptying a graduated pipette fully. Do not refer to these types of mistake when you are...

Once you have collected, tabulated and displayed your results, you can use them to draw a conclusion. When you are thinking about a conclusion, look right back to the start of your experiment where you were told (or you decided) what you were to investigate.For example:• In investigation 1, investigating the effect of...

When you have collected your data and completed your results table, you will generally want to display the data so that anyone looking at them can see any patterns.1. Line graphs Line graphs are used when both the independent variable and the dependent variable are continuous. This is the case for the potato strip...

You will often need to construct a table in which to record your measurements, readings and other observations. It is always best to design and construct your results table before you begin your experiment, so that you can write your readings directly into it as you take them.Let's think about investigation...

You will often be asked to take measurements or readings. In biology, these are most likely to be length, mass, time, temperature or volume.You could be taking readings from a linear scale (for example, reading temperature on a thermometer, reading volume on a pipette, or reading length on a potometer tube). You could...

Many of the experiments that you will do during your AS course, and usually Question 1 in the examination paper, will investigate the effect of one factor on another. These factors are called variables.Types of variablesThe factor that you change or select is called the independent variable. The factor that is affected...