Download presentation
Presentation is loading. Please wait.
1
Lab Safety and the Scientific Method
Virginia Standard of Learning BIO.1a-m
2
BIO SOL: 1 a-m The student will plan and conduct investigations in which: observations of living organisms are recorded in the lab and in the field; hypotheses are formulated based on direct observations and information from scientific literature; variables are defined and investigations are designed to test hypotheses; graphing and arithmetic calculations are used as tools in data analysis; conclusions are formed based on recorded quantitative and qualitative data; sources of error inherent in experimental design are identified and discussed;
3
BIO SOL: 1 a-m The student will plan and conduct investigations in which: validity of data is determined; chemicals and equipment are used in a safe manner; appropriate technology including computers, graphing calculators, and probeware, is used for gathering and analyzing data and communicating results; research utilizes scientific literature; differentiation is made between a scientific hypothesis and theory; alternative scientific explanations and models are recognized and analyzed; and a scientific viewpoint is constructed and defended (the nature of science).
4
Lab Safety Listen to instructions of your __________.
Work safely and cautiously Tie back hair, fasten loose clothing, and secure dangling jewelry Do not taste and touch chemical No playing around in the laboratory Know the location of safety equipment & fire evacuation routes Use safety wear when necessary
5
Equipment you MUST know!
All parts of the ____________. Microscope slides and cover slips Graduated Cylinder Petri dishes
6
Graduated Cylinder – The meniscus
Jan consistently read the volume of liquids as shown. How would this practice impact her work? a) Her measurements would be very accurate b) Her measurements would be too high. c) Her measurements would lack precision. d) Her measurements would be too low for less dense liquids.
7
The petri dish SOL question
In the lab setup pictured below, a student is trying to determine the effect of pollutants on the growth of three groups of seeds. The results will not be valid because the experiment does not have a
8
The Scientific Method An organized way to solve a problem through experimentation & ______________.
9
The 6 Steps of the Scientific Method
10
1. State the __________ Form a question about a specific event or reaction EX: Mouthwash kills bacteria. Which brand works best?
11
2. Collect Information Research the problem Make ____________
EX: Read the labels of 3 common brands of mouthwash and see which has the most antiseptic (germ-killing) ingredients.
12
Observation vs Inference
Observations- made with the ___________ ____________ _____________ ___________ – a conclusion based on ________ and ________. Ex: Jimmy said he was not feeling well yesterday. He did not come to school today. I infer that he did not come to school because he is sick.
13
3. Form a hypothesis Make an educated guess based on your _______________________. A hypothesis can be recognized by an “_____, ________” statement. EX: If Listerine has more antiseptic ingredients than Scope or Wal-Mart brand, then it will kill more bacteria.
14
4. Design an Experiment Devise a way to test your hypothesis. Create a
____________ experiment.
15
ONLY ____ condition is changed!
A controlled experiment MUST have __ groups. CONTROL GROUP: all conditions remain the ______ EXPERIMENTAL GROUP: only the condition that you are testing for is _________. ONLY ____ condition is changed!
16
Establish the variables for your _______________.
_______________ VARIABLE: the variable that is changed, manipulated _______________ VARIABLE: the change caused by the manipulation of the independent variable
17
_______________- variables that will be kept the __________ in the _____________ group and the __________________ group. Ex: The control group will receive 10ml of water and each experimental group will receive 10ml of each mouthwash.
18
Trials __________________ groups that are exposed to the same conditions in an experiment. Minimum of _____ trials (the experiment must be done a minimum of 3 times )
19
Mouthwash Experiment Control Group -no mouthwash Experimental Group
Petri dish Bacteria grown from swab Listerine Experimental Group Scope Wal-Mart brand
20
_________________ _______________________ Mouthwash Experiment
INDEPENDENT VARIABLE: _________________ DEPENDENT VARIABLE: _______________________
21
5. Collect & Analyze Data Run the experiment & collect the _________.
22
2 Types of Data ___________ITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart __________ITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities
23
How do scientist measure quantitative data?
All scientist use the ______ (metric) system . Based on units of _________ Most countries use the metric system Standard Units of Measure Volume- ___________ Mass- ____________ Distance- __________
24
How is data recorded? Charts Graphs
Used for qualitative and quantitative data Graphs Type of graph used is dependent on the type of data collected.
25
How to Graph Identify your variables/Label your axis
__ goes on the _________ (horizontal) ___ goes on the _________ (vertical) Determine the range and scale Plot your points Title graph
26
Types of Graphs Pie Chart Bar Graph Histogram Line Graph Scatter Plot
27
QUANITATIVE EX: Area of Inhibition for Mouthwash Brands
QUALITATIVE EX: The control group and the Wal-Mart brand have a strong smell; the Listerine & Scope don’t smell as bad. QUANITATIVE EX: Area of Inhibition for Mouthwash Brands Control Listerine Scope Wal-Mart 5 min 0 mm 3 mm 2 mm 1 mm 10 min 4 mm 15 min 6 mm 5 mm 20 min 8 mm
28
_______________________
6. Draw Conclusions Determine from the data collected if the hypothesis was correct or incorrect _______________________ EX: Listerine did kill more bacteria than the other brands because it had more antiseptic ingredients.
29
The 7th Step __________/_________ your findings
Scientists often publish their findings in scientific journals/magazines, peer-reviewed journals
30
Let’s Review!
32
________________ ____________- a possible explanation to a question based on information the scientist has already gathered - If experiments show a hypothesis to be correct, other scientists may accept it as support for a scientific theory. EX: Plants obtain their energy from the sun.
33
____________ ________________ Theory- a ________ statement of why things work based on hypotheses that have been ____________ many times _______________ Generation Theory stated that living things can arise from non-living matter. ____________ _______ believed that maggots formed naturally from rotting meat.
34
Sometimes theories are __________
_________ __________ was one of the scientists that helped to confirm that the Spontaneous Generation Theory by Francesco Redi was wrong!
35
Microscope Parts Eyepiece Body Tube Revolving Nosepiece Arm
Objective Lens Stage Stage Clips Coarse Focus This is the exact version of the microscope used in class. Students will be identifying the parts on the microscopes at their desks as we go along and what their functions are. Diaphragm Fine Focus Light Base
36
Total Magnification Formula
Objective lens Ocular Total Magnification Scanning Power 4X 10X Low High 40X
37
Using High Power Switch to ______ power
Switch to ______ power objective Do _____ use the Coarse Focusing Knob Use the Fine Focus Knob to bring the slide Have students exchange slides so they can look at different things, walk them through using the high power objective to focus slides. Emphasize not using the coarse objective during this process, as it will crack the slides. What can you find on your slide?
38
Equipment - MICROSCOPE
39
HOW TO MAKE A WET MOUNT SLIDE
Use a temporary microscope slide and a ________________. Specimens will appear with a ________ image
40
Wet mount SOL Question The picture shows a coverslip correctly being lowered onto a slide. This method is used because it —
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.