Scientific Inquiry & Lab Skills Topics 8 & 9 Scientific Inquiry & Lab Skills

Topic 8 Vocabulary on pp 146 & 166 Especially: controlled experiment, independent and dependent variable, support, refute and validity.

Topic 8 Inquiry involves observations and inferences and ultimately leads to use of the scientific method

Topic 8 HYPOTHESIS… What to say… an attempt to explain what has been observed in a way that can be tested. What is crucial… THEY ARE NEVER WRITTEN IN QUESTION FORM, EVER! … THEY ARE MOST OFTEN WRITTEN IN “IF, THEN, BECAUSE” FORM. The if will almost always reflect the I.V., the then will almost always reflect the data you will collect (D.V) and the because almost always explains why/conclusion. Ex. If this hormone is applied to plant leaves, then it will grow faster because the hormone provides necessary chemicals for growth.

Topic 8 Designed an Experiment (controlled experiment) MUST be REPEATABLE What is it you will measure? Data collected= Dependent Variable What is it you will control/manipulate?= Independent Variable What will use as a reference/starting point?=Control What conditions will be the same for all?=variables THERE CAN ONLY BE ONE VARIABLE THAT CHANGES (I.V.) Large sample sizes with repeated trials provides much more accurate information, less possibility for error. Likely to provide VALID results.

Topic 8 Organize data into tables, charts and graphs: all must have titles Graphs see page 155 green box Must have title: The Effect of IV on DV with x axis being the IV and the y axis being the DV Scale axes without using breakers and making sure there are equal increments being used Plot points accurately Make a legend if need be

Topic 8 Data tables must have titles and the IV (x axis) is most often the left column, the DV (y axis) is most often the right column. Final steps: Draw conclusion based on findings/results. Have peers review.

Topic 9 Use the metric system! Based on multiples of 10! K H D B D C M Length= meters Volume= liters Mass= gram Temperature= Celsius

Topic 9 Look at sample questions p 168-169 # 1-8 Microscope: Know slide making techniques and why we stain Larger & brighter field of view= low power but less detail Smaller &darker field of view=high power but more detail Image seen under scope is UPSIDE down & BACKWARDS Movement is opposite direction to appearance Use coarse adjustment first then fine, but never use coarse on high power

Topic 9 Additional lab procedures: Gel Electrophoresis Chromatography Indicators D. Key Dissection KNOW SAFETY PROCEDURES IN THE LAB