Doing reserach: cress

• Biologie
• Middelbare school
• mavo, havo, vwo
• Leerjaar 1

Conducting Research in Biology

The Cress Practical Assignment

Learning Objectives for Today:

• You can name the 6 steps involved in conducting research.
• You can design a small research project on your own.

The Research Steps

0. An observation and/or idea

1. Formulating the research question

2. Making a hypothesis

3. Creating a list of materials

4. Describing the method

5. Collecting and processing results

6. Drawing a conclusion

1. What do I want to investigate?

Research Question

• A question that describes what you want to know or discover.

In this case, you have already been given the research question:

What is the effect of light on the growth of cress plants?

2. What is my hypothesis?

Hypothesis

• What is the expected answer to the research question?
• Also, provide a prediction: If I ……. do, then ……. will happen.
• Support your hypothesis with background information, if possible.

What do you think?

What is the effect of light on the growth of cress?

2. What is my hypothesis?

Hypothesis

Example

• I expect that cress seeds will not grow without light. Plants need light for photosynthesis and energy, which is not possible without light. If I place the cress seeds in the dark, I expect the seeds will not germinate.

3. Materials

Materials

A list of everything needed to perform the experiment.

Example:

• 2 small bowls
• Cotton wool
• A cup of water
• 30 cress seeds

4. Method

method

Step-by-Step Execution of the Experiment.

Why this method?

Example:

1. Take two tubes and place a large amount of cotton wool inside each one.
2. Fill the tubes with water until the cotton wool is completely submerged.
3. Wait for the cotton wool to absorb the water, then pour out any excess water.
4. Place 10 cress seeds in each tube.
5. Put one tube in a location that remains dark for 24 hours a day, and place the other tube in a location with light for 24 hours a day.
6. Examine the tubes after 7 days.

5. results

Results

What happened during the experiment?

Only facts!

Data presented in a table and/or graph, such as the length of the plants.

Photos/videos of the experiment.

Example:

6. What conclusion can I draw?

Conclusion

Answer the research question.

Refer to the results and the hypothesis.

The research question for this experiment was: ‘What is the effect of light on the growth of cress?’

The answer is that cress seeds grow taller when they are grown in the dark. This is shown in Table 1, where the cress seeds grown in the dark are taller than those grown in the light.

The hypothesis was therefore incorrect: cress plants grow both in the dark and in the light.

Assigment

Design your own (simple) experiment using cress seeds.

Choose a liquid (or condition) that you want to investigate.

• What is your hypothesis, and why?
• What materials do you need?
• What method will you use? (Describe this very precisely, so someone else can perform your experiment correctly.)

So, now....

How will I conduct my research?: What is the effect of ... on the growth of cress plants?

Write down the following in your notebook:

• How many seeds do you need for your experimental group and how many for the control group?
• What do you need to carry out the experiment?
• Where will you conduct the experiment?
• How will you ensure that other factors, besides the one you are investigating, do not affect the results?
• How will you measure and present the results of the experiment?

Once you have written down the answers to all these questions, present your plan to your teacher. If the plan is approved, you will receive seeds and can start your experiment.