The Scientific Method in Biology — Reading Comprehension

Biology seeks to answer questions about living things using a careful process called the scientific method. For example, a scientist may notice that some plants grow taller near a window than others placed farther away. To understand why this happens, scientists follow a series of logical steps: making observations, forming a hypothesis, designing and conducting experiments, collecting and analyzing data, and drawing a conclusion. Applying this process helps ensure discoveries are based on evidence, not just guesses or opinions.

How the Scientific Method Works

The first step is observation—scientists gather information using their senses or tools. For instance, they might measure how fast plants grow under different light conditions. Next, they create a hypothesis: a testable explanation for what they observed. In our plant example, a hypothesis could be, "Plants exposed to more sunlight will grow taller than those given less light." To test the hypothesis, the scientist sets up a controlled experiment where only one variable—the amount of light—is changed, while all other factors like water, soil, and temperature remain constant. This helps ensure that any differences in plant growth are actually caused by light, not something else. Data is collected—usually through measurements or observations—and then analyzed to see if it supports or contradicts the hypothesis.

Applying the Method in Real-World Biology

Biologists use the scientific method to answer questions in many areas, from plant growth to animal behavior. In animal studies, researchers might observe how changes in food availability affect foraging habits in birds. Variables like the type or amount of food offered are carefully controlled. Sometimes, hundreds of animals or plants are observed to account for variability among living things. Data is often organized in tables or graphs to spot patterns and trends. For example, if plants in sunlight grow 25% faster than those in shade, the data provides clear evidence supporting the hypothesis. In some cases, unexpected results lead to new questions and further experiments, showing how science is a continuous, self-correcting process.

Challenges Unique to Biological Research

Studying living organisms brings special challenges. Unlike chemicals in a test tube, living things are highly variable and can change over time. Biological experiments often require large sample sizes and may take weeks, months, or even years to complete. Ethical considerations are important, especially when working with animals or humans. Scientists must design experiments that minimize harm and respect living creatures. Sometimes, natural events like disease or weather can affect results, requiring careful analysis and sometimes repeating experiments.

By following the scientific method, scientists make discoveries that help us understand life’s complexity and solve real-world problems, from improving crop yields to protecting endangered species. This approach is central to how we build new knowledge in biology and connect it to broader scientific principles, like cause and effect in living systems.

Interesting Fact: Some plant experiments, such as studying tree growth, can last for decades or even centuries, with data collected by multiple generations of scientists!

Which of the following is the best example of a hypothesis?

What is the purpose of a controlled experiment?

In the passage, what is the first step of the scientific method?

Which step comes after collecting data in the scientific method?

What does the word 'variability' mean in the passage?

What is the meaning of 'ethical considerations' as used in the passage?

Why do scientists use large sample sizes in biology experiments?

How might natural events, like weather, impact biological experiments?

True or False: In a controlled experiment, more than one variable is changed at a time.

True or False: The scientific method is only used in chemistry, not biology.