Super Simple Biology: The Ultimate Bitesize Study Guide

Book Preface

How science works
Science is not merely a collection of facts. It is also a way of discovering new facts by having ideas and testing them. Scientists use ideas (hypotheses) to make predictions they can test with experiments.
This process of testing ideas with experiments is known as the scientific method.
1. Make an observation
The first step in the scientific method is to make an observation. For instance, you might notice that spring bulbs in a garden always flower first at the sunniest end of the garden.
Key facts
✓ The scientific method involves testing hypotheses with experiments.
✓ An experiment cannot prove a hypothesis is true—it can only support it.

2. Form a hypothesis
The next step is to form a hypothesis—a scientific idea—that might explain the observation. For instance, one possible explanation is that flowers emerge in the sunny spot first because the soil is warmer there.
3. Perform an experiment
You test a hypothesis by carrying out an experiment and collecting evidence. If temperature makes spring bulbs grow faster, you might set up an experiment to grow bulbs of the same plant species in identical soil containers at three different temperatures. To collect reliable evidence, you might grow many bulbs at each temperature. This makes it easier to spot if something has gone wrong, such as a plant not growing normally

4. Collect data
Scientists collect results (called data) from an experiment very carefully, often by taking measurements. These may be repeated to make sure they are accurate. The results are often recorded in a table.
Fact or theory?
If a scientific theory has been tested many times and has never failed, it might eventually be accepted as a fact. For instance, we now accept the theory that germs spread diseases as a fact. The theory that fossils are the remains of prehistoric organisms is also accepted as a fact. However, no scientific theory or fact can be proven true beyond doubt, as new evidence that a theory can’t explain could always come to light.

5. Analyze the results
To make the results easier to analyze, they are often shown on a graph. The graph here shows the average heights of the plants over 25 days. In this case, the results support the hypothesis that warmer temperatures make flowers emerge sooner. The results are considered to be repeatable if the same experiment is carried out several times and similar results are obtained.
6. Repeat the experiment
A single experiment doesn’t prove a hypothesis is true–it merely supports it. Scientists usually share their results in scientific journals so that others can repeat the experiment and verify the results. This is known as peer review. After many successful trials, a hypothesis may be accepted as a theory.