What Is Biology?: Tutorial

Scientific Tools

Advancements in research tools are key to the growth of most sciences. Probably the first big advance in scientific tools was the invention of the microscope. The invention of computers also has made an enormous contribution to all the sciences.

Themes in Biology

Although there are many areas of study within biology, several themes have emerged: *Science as process*: The word science is derived from a Latin verb meaning "to know." That is, biology is an ongoing process of learning, not just a list of facts. *Evolution*: Evolution is simply how living things evolve, or change, over time. It explains inherited similarities in organisms and causes of variation. *Energy transfer*: All organisms perform work as they move, grow, and reproduce and need an energy source to do so. Organisms constantly transfer energy to their surroundings, and vice versa. This transfer involves the conversion of one form of energy into another. *Continuity and change*: Organisms reproduce to ensure their species continues. But combining genes also results in variations in offspring. *Relationship of structure to function*: Every type of organism has developed parts to adapt to its habitat. Birds have different kinds of beaks, and plants have different kinds of seeds, for example. *Regulation*: Also called homeostasis. Cells, animals, and ecosystems work to maintain stable internal conditions, such as body temperature, even when external conditions change. *Interdependence in nature*: The flow of energy and cycling of matter are the two processes that determine the relationships between organisms and their surroundings. *Science, technology, and society*: Scientific inquiry should consider the ethical and social impact of the research. In other words, scientists must make decisions based on what society should do over what it can do.

Newer Research Methods

As scientists learned more about nature and science, they began to challenge established ideas like spontaneous generation. This was the beginning of what is now known as scientific inquiry. Scientists use three key methods to research and analyze data: observation, investigation, and experimentation. Scientific inquiry begins with observation. It is a process in which scientists gather information in an orderly manner. They record their observations, which become data that they categorize. Data is of two types: Numerical data is called quantitative data. Descriptive data, data that cannot be counted, is called qualitative data. An example of quantitative data is, "A plant has 10 leaves." An example of qualitative data is, "The leaves are healthy." Based on the data she's gathered, a scientist may propose a hypothesis. A hypothesis is a question framed by a scientist to explain a set of observations. It's a prediction that must be testable. So the scientist must conduct experiments or do more investigation. A hypothesis isn't always proven correct. Experiments or investigation may prove the hypothesis wrong. Then the scientist must reformulate the hypothesis and start over again. Scientists use controlled experiments to test hypotheses. In an experiment, factors such as temperature, light, time, and materials can change if they're not controlled. These factors are called variables. To properly test a hypothesis, scientists change only one variable at a time so that they can interpret the results accurately. An experiment must be repeated enough times to ensure that the outcome is always the same. Once testing is complete, the scientist analyzes the results and then concludes that her hypothesis is correct, partially correct, or just plain wrong. Once a hypothesis is accepted as correct and after repeated testing, it becomes a theory. A theory may be disproven if contrary evidence later becomes available. Theories are different from scientific laws, which are statements accepted at face value because they have always been observed to be true. Scientific experiments are based on the assumption that nature behaves consistently. Hence, the conclusions derived from one experiment can be applied to all similar instances. Today, researchers publish detailed descriptions of their experiments in scientific journals to enable other scientists to test their hypotheses by imitating their experiments.

Biology in Your Life

As you work through this lesson, think about how biology—the study of life—affects you every day. It explains the human body and describes conditions of good health. It teaches you about the causes of disease and provides the means for diagnosis and treatment. It helps you understand other life-forms and their roles in your environment. It identifies environmental problems and demonstrates ways to solve them. In recent decades, technology has come to play an important role in the study of life. In this lesson, you will see how advancements in technology have led to discoveries our ancestors could not even have imagined. Let's take a look.

Applied Biology

Biological research has contributed directly to life as we know it: how we grow crops, how we identify and treat diseases, and even what foods we eat are all direct results of biological research. Biotechnology (for example, converting corn into fuel) and food technology (for example, developing tomatoes with skins tough enough to be transported) are examples of how we see biology applied every day. Researchers who pursue a specific area of interest may someday make great achievements. For example, an interest in diseases could lead to finding a cure for diabetes. Or an interest in plants could lead to discovering more efficient ways to grow our food without losing its good taste.

Summary

Biology, the study of life, is the science on which many kinds of study are based: medicine, nutrition, molecules, ecosystems, and more. Several themes, such as evolution and energy transfer, are consistent throughout Biology's many disciplines. Research methodologies have undergone a significant change over the years. Observation, investigation, and experimentation remain the backbone of research, but microscopes and computers have greatly enhanced scientific knowledge and study. The data gathered by researchers must be organized and analyzed so that it is useful. Tables and graphs are good ways to represent data.

Math Skills and Data Analysis

Data is of no use unless it is organized and analyzed. Large amounts of data need to be organized in an appropriate manner to identify expected changes in variables during an experiment. One way to organize data is to record it in a table and represent it in a graph. Data analysis consists of four major steps: Classify the data into appropriate categories. Draw an inference from the data. Calculate the appropriate values. Draw a conclusion about the data.

Laboratory Techniques

Let's look at how a scientist might use an electron microscope for research. Consider a microbiologist studying the structure of a virus under an electron microscope. He is exploring this research question: "What is the structure of the proteins that coat a virus?" The microbiologist wants to test these hypotheses: If the virus behaves a lot like HIV, the virus coat will have two receptor proteins. If the virus is grown on nutrient agar, the coat proteins will be modified. Here, the first hypothesis is testable because the receptor proteins can be viewed through the microscope. However, the second hypothesis cannot be tested because the conditions to test it can never be created. A virus cannot grow on nutrient agar, which is a cell-free medium.

Specialized Fields of Biology

Like all sciences, biology includes many specialized fields. Given the size and diversity of our natural world, it would be impossible for any one type of biologist to study all living things. Traditionally, there were two main branches of biology: botany (the study of plants) and zoology (the study of animals). Today, there are dozens. Specializations range from the study of cells to organisms to ecosystems and beyond. For example, histologists study microscopic animal and plant tissues, and ecologists study how organisms relate and interact with their environment and other organisms. The field of biology has many other "ists" that all fall under the broad umbrella of the same science.

Microscopes

Microscopes magnify objects to make them appear larger than their actual size. One type is a light microscope. It magnifies objects to 1,000 times their actual size and produces a visible image by focusing visible light rays. You can see living cells with the help of a light microscope and certain stains and dyes to enhance visibility. Another type is the electron microscope. It uses a focused beam of electrons to magnify samples. The image created is 1,000 times more detailed than an image from a light microscope. Electron microscopes operate in a vacuum. That means samples must be dehydrated before they are placed in the microscope, a requirement that makes electron microscopes useless for viewing living organisms.

Early Days of Science

Our ancestors were as curious about their lives as we are about ours. They too posed questions and provided answers. Initially, these answers were not the result of scientific research. For instance, smallpox was thought to be a curse. But experimentation started centuries ago. Aristotle researched a number of disciplines. He dissected animals and observed their behavior in their natural environment. He classified living things on the basis of complexity of structure and function. During Aristotle's times, people believed that nonliving matter produced living things. People based their belief on what they saw: maggots appearing seemingly out of nowhere on discarded food. This idea was called spontaneous generation.

Metric System

Standardized measurement is essential in scientific research. Today, most scientists use the metric system of measurement. The units of this system are assigned specific standards and are scaled in multiples of 10. The original metric system was revised in recent years and is now called the International System of Units, or SI for short. This system measures length in kilometers, mass in kilograms, volume in liters, and temperature in degrees Celsius.

Biology and Other Sciences

The word biology means the study of life. In fact, biology is often called life science. But biologists also need to study how living organisms interact with nonliving objects. Several interdisciplinary branches of science have emerged to accommodate this need. Biochemistry is the study of chemical processes in living organisms. Bioinformatics is the application of information technology in biological analysis. Other common interdisciplinary branches include biophysics (the science of the application of physics to biological processes and phenomena), biometry (the science of measuring and analyzing biological data), psychology (the study of the mind), and sociobiology (the study of social behaviors in animals).

Rita loves animals and wants to work at a wildlife sanctuary. Which branch of biology should she study?

Zoology