Video Lesson:

Lesson Objective:

At the end of this lesson, you will be able to:

• explain about scientific method
• explain about the meaning of hypothesis
• practice about formulating hypothesis
• practice doing scientific experiment and drawing a bar graph

Welcome to the section on the Scientific Method! By the end of this lesson, you will have a solid understanding of the scientific method, the importance of forming hypotheses, and the skills to practice these concepts through hands-on experiments.

Biology is a science of inquiry. What comes to your mind when you hear the word “science”? Biologists are always curious about why things happen or how things happen. By asking questions and seeking science-based responses known as the scientific method, they come up with new theories to explain new findings.

The Scientific Method: A Series of Steps

The scientific method involves a series of steps that guide scientists through scientific investigations. By the end of this section, you will be able to:

• Explain the scientific method
• Understand and explain the meaning of a hypothesis
• Practice formulating hypotheses
• Conduct scientific experiments and draw bar graphs to represent your data

General Steps of the Scientific Method:

1. Observation: The scientific study begins with careful observations, often identifying a problem to solve. Observations can be made directly using your sense organs or indirectly using scientific tools like microscopes.
2. Asking Questions: These observations usually lead the scientist to ask questions. This step is crucial for inquiry.
3. Forming a Hypothesis: A hypothesis is a proposed scientific explanation for a set of questions. To solve a problem, several hypotheses can be proposed. Scientific hypotheses should be testable. For example, if you observe that plants need sunlight to grow, your hypothesis might be, “If plants receive more sunlight, then they will grow taller.”
4. Testing the Hypothesis: Hypotheses can be tested through experimentation. Any scientific experiment must be reproducible, meaning other scientists should be able to perform the same experiment and achieve similar results. If a hypothesis is not supported by experimental data, a new hypothesis can be proposed.
5. Making Conclusions: Scientists consider their original hypotheses and assess whether the new data supports or refutes them. If the data supports the hypothesis, it remains a possible explanation. If not, the hypothesis is rejected, and new hypotheses are formulated.
6. Communicating Findings: When scientists complete their work, they write a paper explaining their methods and results. These papers are submitted to scientific journals and help advance knowledge in the field. Sharing findings is crucial for scientific progress and education.

Example of Hypothesis Testing in Everyday Life:

Example One:

Suppose you notice that your favorite plant is wilting even though you water it regularly.

1. Observation: The plant is wilting despite regular watering.
2. Question: Why is the plant wilting?
3. Hypothesis: The plant may not be getting enough sunlight.
4. Experiment: Move the plant to a sunnier location and monitor its condition over the next week.
5. Conclusion: If the plant begins to thrive in the sunnier location, the hypothesis is supported. If it continues to wilt, you might formulate a new hypothesis, such as the plant having a disease or needing different soil.

Example 2:

Objective: To determine the importance of temperature for seed germination.

Steps and Instructions:

1. Gather Materials:
   • Bean seeds
   • Three containers for germinating the seeds
   • Water
   • Ruler
   • Notebook for recording observations
2. Set Up the Experiment:
   • Germinate bean seeds in three different temperature conditions:
     • Condition One: Place one container at room temperature.
     • Condition Two: Place the second container in a colder place, such as a refrigerator.
     • Condition Three: Place the third container in a hotter place, such as inside the kitchen near a heat source.
3. Formulate a Hypothesis:
   • Room Temperature: Seeds will germinate normally.
   • Colder Place: Seeds will have slower germination or may not germinate at all.
   • Hotter Place: Seeds will germinate faster but may have weaker seedlings due to excessive heat.
4. Conduct the Experiment:
   • Water the seeds regularly and ensure each group gets the same amount of water.
   • Record the day each seed begins to germinate (first signs of sprouting).
   • Measure the length of the seedlings each day using a ruler and record the observations on the notebook.
5. Create a Bar Graph:(See below)
   • X-axis: Days of germination (1st day, 2nd day, 3rd day, etc)
   • Y-axis: Length of the germinated plants (measured in cm).
6. Interpret the Results and Conclude the Experiment:
   • Room Temperature: Seeds germinated at a normal rate with steady growth.
   • Cold Temperature: Seeds germinated more slowly and showed slower growth.
   • Hot Temperature: Seeds germinated quickly but may show signs of stress or weaker growth over time.
   • Conclusion: Temperature significantly affects the rate of germination and growth of bean seeds. Optimal germination occurs at room temperature, while extreme temperatures (both cold and hot) can negatively impact germination and seedling growth.
7. Report Your Results: Based on the experiment, it is observed that bean seeds germinate most effectively at room temperature. Seeds placed in a colder environment showed delayed germination and slower growth, while those in a hotter environment germinated quickly but did not sustain healthy growth over time. This indicates that while temperature is a crucial factor in seed germination, extreme temperatures can hinder the process. The results highlight the importance of maintaining optimal conditions for successful seed germination and growth.