Life Science Introduction What 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 used when the data is not connected

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 total 3 tested with low amount of water 3 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. http://www.youtube.com/watch?v=TC3WIh0JDs8&feature=related 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.

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, width, distance, thickness, girth, etc. 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 Mass milligram 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 L cubic centimeter cm³ 1 cm³ 1 mL liter L 1000 L 1 m³ cubic 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!!!