Living Systems

Chapter One: Studying Life

• 1.1 Measurements

• 1.2 Thinking Like a Scientist

• 1.3 Graphs

1.2 Thinking like a scientist

• Science is a process of thinking and learning about the world around us.

• The scientific method is a process used by scientists to answer questions.

Can mud turn into worms?

1.2 Steps of Scientific Method

1.2 Hypothesis

• A hypothesis is a prediction that can be tested with an experiment.

Maria’s Hypothesis:Worms come to the surface after a heavy rain so they won’t drown in wet mud.

1.2 Designing Experiments

• A variable is a factor that affects how a system works.

• When designing an experiment, you identify the important variables in the system and change only one variable.

Maria changed the soil type in her experiment.

She did NOT change the worms, how long they stayed in light or the temperature.

1.2 Designing Experiments

• An experiment is a controlled test to determine if a hypothesis is correct.

• A system is a group of factors that are related in some way.

Maria’s experiment took place in a tank. The system included the worms, tank and soil.

1.2 Data and Conclusions• Each time you do the same experiment, it

is called a trial.

Maria repeated her experiment 4 times. This gave her more results to consider.

1.2 Data and Conclusions• After analyzing

the data, you should be able to state whether your hypothesis is correct, partially correct, or incorrect. Maria compared data

from tank 1 to tank 2.

1.2 Data and Conclusions• A lab report is a

good way to communicate the results of an experiment to others.