The Science of Biology

The Science of Biology Objectives- After you are done viewing this presentation you should be able to do the following: -Explain the goal of science, specifically the study of biology. -Describe how scientists formulate and test hypotheses. -Identify the independent variable, dependent variable, and control.

Thinking Like a Scientist • Scientific thinking usually begins with observations, the process of gathering information about events or processes in a careful, orderly way. • Observation generally involves the use of the senses (sight, smell, touch, and hearing)

Thinking Like a Scientist • The information gathered from observations is called data. • Two main types of data: quantitative and qualitative • Quantitative counts or measures data • One scar on a manatee’s back • Qualitative describes data • The manatee’s scar is colored white

Thinking Like a Scientist • Scientists use the scientific method to find solutions to a problem • They first observe the problem and then come up with a hypothesis • A hypothesis is a proposed scientific explanation for a set of observations • Scientific hypothesis must be proposed in a way that enables it to be tested

Thinking Like a Scientist • Science is constantly changing or an ongoing process---a process that involves asking questions, observing, making inferences, and testing hypotheses • An inference is a logical interpretation based on prior knowledge or experience

Designing an Experiment • Asking a Question • In order to determine how something occurs, people have to ask questions or identify a problem to be solved by asking a question • For example: How do new living things, or organisms, come into being? • Why do maggots appear on meat?

Forming a Hypothesis • A hypothesis is an educated guess about the answer to an identified problem. • Hypotheses are generally stated in an if/then format For example: If meat is allowed to sit out then it can be converted into living matter.

Setting Up a Controlled Experiment • The factors in an experiment that can change and have different values are called variables • A hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled • This type of experiment is called a controlled experiment

The variable that is deliberately changed is called the manipulated variable or independent variable • The variable that is observed and that changes in response to the manipulated variable is called the responding variable or dependent variable

A manipulated variable is the variable which you deliberately alter the value of. So, you will know the values of this variable before you do the experiment. • A responding variable is the variable which you have to measure to get your results. So, you do not know the values of this variable until you measure it.For example, to find out if your heart rate depends on exercise, you could do different amounts of exercise (the manipulated variable) and measure the heart rate (the responding variable).

Recording and Analyzing Results • Scientists record their observations or findings from an experiment in paper form, computer, or journals • The data collected from an experiment will need to be organized so that it can be effectively analyzed

Drawing Conclusions • Scientists use the analyzed data from an experiment to evaluate the hypothesis and draw a valid conclusion • That is they use the evidence they found to either agree or disagree with the hypothesis

Repeating Investigations • In order to validate the conclusions drawn from an experiment that are either supporting or rejecting the hypothesis, the same experiment must be repeated and must yield the same results.

How a Theory Develops • As evidence from numerous investigations builds up, a particular hypothesis may become so well supported that scientists consider it a theory. • In science, the word theory applies to a well-tested explanation that unifies a broad range of observations

Scientific Method

The Science of Biology