Life Science IntroductionWhat is Science?

Life Science

EARTH SCIENCE

Physical Science

Life Science Branches

Scientific Method

• A series of organized steps used to solve a problem

State the Problem

• Usually formed when an observation is made that cannot be explained

• It is important to clearly state what your problem is to avoid any confusion later in the scientific method.

Research your Problem

• Project research is collecting information from reliable sources.

• Research must be conducted so a valid hypothesis can be written

Writing a Hypothesis• an explanation that can be tested• It is written: (variable is something that can change)

• If (independent variable), then (dependent variable).• Independent variable is the variable that is changed and

tested in the experiment. It is also called the manipulated variable.

• The dependent variable depends on the independent variable. It is also called the responding variable.

Creating an Experiment to Test the Hypothesis

• a step by step procedure that can be easily followed by others.

• All conditions must be constant except the independent variable. (only one can be tested)

• Many experiments contain a control which is the standard to which the outcome of a test is compared.

• At least three trials to guarantee valid results

Observations/Analyze the Data• The data is collected and placed in a data table for

easy viewing.

• Data is best graphed so the results can easily be seen. Trends in the data can be seen.

Types of Graphs

• Line graph shows change over time

• Circle graph uses percentages of a whole

• A bar graph is usedwhen the data is notconnected

Conclusion• A conclusion is a logical explanation to a

question based on data and observations• It will state whether the hypothesis is

supported or not• A conclusion can also state problems or

suggestions for further testing

How does the amount of water effect plant growth?

• Research: Does the amount of food given to a certain plant effect the growth of that plant?

• Hypothesis: If the plant is watered with 1 liter once a week it will grow the tallest.

• Experiment: 9 plants total3 tested with low amount of water3 tested with the recommended amount of water (control group)3 tested with too much water.

Variables

• Independent variable: amount of water• Dependent variable: growth of the plants• Constants; same sized plants, same sized pots,

same soil, same amount of sunlight• Control: the usual amount of water a plant

needs

Analyze the Data• The data is placed in a data table and then

graphed.• What kind of graph?• Conclusion: Was your hypothesis supported or

not supported? It is OK to be not supported. The objective of the scientific method is to investigate a problem and work toward a solution. Even if you have disproved your hypothesis you have still done a good job if you correctly applied the scientific method.

http://www.youtube.com/watch?v=TC3WIh0JDs8&feature=related

Models and Simulations• Models can be used when what is being studied is either

too big or too small to be easily seen.• Simulations are used when the “real thing” is not

available.

Classification System

Safety in the Lab

SI units of Measurements

• Based on the number 10• Easy to read and understand• Almost every country in the world uses it

except United States!

Length or Distance

• Length: the unit is meter

• A metric ruler or meter stick is used

Length, width,distance, thickness,girth, etc.

millimeter mm 10 mm= 1 cm

centimeter cm 100 cm= 1 m

meter m

kilometer km 1 km= 1000 m

Mass and Weight• Mass is measured in grams, it is the amount of

matter in an object

Measured with a triple beam balance or electronic balances

Weight is measured in newtons, it is the amount of gravity that pushes down on an object measured with a spring scale

Massmilligram mg 1000 mg= 1 g

gram g

kilogram kg 1 kg= 1000 g

Volume

• Volume is measured in liters, cubic centimeters

• Measured with graduated cylinders

Volume

milliliter mL 1000 mL= 1 Lcubic centimeter cm³ 1 cm³= 1 mL

liter L 1000 L= 1 m³cubic meter m³

Density• Density is the amount of matter in a given space, it

never changes.• Density is mass divided by volume

• Time is measured in seconds or hours• Temperature is measured in degrees Celsius • Probeware can be used to collect data

Tools used by scientists

Periodic Table

• Elements of life include hydrogen, carbon, oxygen, and nitrogen.

Microscope

Microscope

• Fill in your diagram with labels and explanations.

• Remember that if you do not gently lower the object near the slide, you can crack the slide and damage the microscope.

http://www.youtube.com/watch?v=Swcz_TJMz0I&feature=plcp

Any questions?

• It’s alive!!!