Chapter 1.2 The Methods of Biology

Observing and Hypothesizing Curiosity motivates biologists to try to answer Knowledge is obtained when one scientist answers a question and then generates other questions. Sometimes the answers are useful in solving other problems.

Methods Biologists Use Scientific method is common steps biologists and other scientists use to gather information and answer questions. Generally include observations and collecting relevant information as well as using logical reasoning and imagination to make predictions and form explanations.

What is a hypothesis? Hypothesis is an explanation for a question or a problem that can be formally tested A hypothesis is normally formed after a scientist makes an observation, reads extensively or has previous investigations. Eventually the scientist will test a hypothesis by conducting an experiment.

What is an experiment? An experiment is an investigation that tests a hypothesis by the process of collecting information in controlled conditions.

What is the difference between a control and an experimental group? A control is the part of an experiment that is the standard against which results are compared. Receives no experimental treatment Experimental group is the test group that receives experimental treatment All other conditions are kept the same during an experiment.

What is the difference between the independent and the dependent variable? Independent variable is the only factor that affects the outcome of the experiment Dependent variable depend on changes made to the independent variable. (results)

Tools Some common tools include beakers, test tubes, hot plates, Petri dishes, thermometers, balances, metric rulers and graduated cylinders Microscopes, centrifuges, radiation detectors, spectrophotometers, DNA analyzers and chromatographers are a few of the more advanced tools used.

What is the experimental results? It is data or information obtained from the investigation. Quantitative data – uses numbers, charts, graphs and tables. Qualitative data – uses your senses, color, sound and visual observations.

After the experiment Scientists will ask several questions including “Was the hypothesis supported by the data?” “Was it not supported?” “Are more data needed?” Scientists will then write a conclusion They also examine their results to make sure they were not biased

Reporting Results Results and conclusions are published in scientific journals for others to research

What is the difference between a theory and a law? A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many different investigations and observations. Theory of Evolution, Big Bang Theory A law is a theory that has been known to be true Law of Gravity