measurement and data collection
DESCRIPTION
Measurement and Data Collection. Pre-AP Biology. Bellwork. You are making a 10% gelatin solution by adding 10 g of gelatin to 100 mL of water and heating to 70 o C. What measurement tools would you use to make this solution? Be ready to share. Objectives. - PowerPoint PPT PresentationTRANSCRIPT
PRE-AP BIOLOGY
Measurement and Data Collection
Bellwork
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You are making a 10% gelatin solution by adding 10 g of gelatin to 100 mL of water and heating to 70oC. What measurement tools would you use to make this solution?
Be ready to share
Objectives
Define the international system of unitsCalculate conversions between metric units Identify scientific tools in the laboratory used
for measurement
Purpose
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• Your experimental results will not mean very much if you don’t have a way to attach numbers or non-opinion descriptions to them.
• The numbers collected must be expressed in units that have the same meaning world-wide
• Scientists have developed tools to assist in data collection
• Proper organization of the data allows the scientist to determine what the data really means.
International System of Units-Metric System
Scientists use the metric or SI systems of units for the measurement of physical quantities-length, volume, and mass
This system of measurement is used world-wide
The metric system is a decimal system of measurement that is scaled on multiples of 10
Prefixes are used in front of the units to indicate powers of ten
Metric System
Measurement Base Unit Symbol
Mass gram g
Length meter m
Volume liter L
Metric Prefixes
Prefix Symbol Power Prefix Symbol Power
tera- T 1012 deci- d 10-1
giga- G 109 centi- c 10-2
mega- M 106 milli- m 10-3
kilo- k 103 micro- 10-6
hecto- h 102 nano- n 10-9
deca- da 101 pico- p 10-12
Metric Conversions
When converting between metric units, follow these rules Always convert to base units first
Ex. To convert cmkm must first convert cm to m then to km
Make conversions using the prefix definition Ex. Use the conversion 1 cm = 102 m rather than 1 m = 100 cm
Example
Conversion of 6.5 km to m Start with what?
Why do I need to learn this method?
You need to fill your swimming pool with your garden hose. The hose releases 1L of water per minute. Your pool holds 1000 kLof water. How long will it take to fill your pool?
Can you answer this by moving the decimal point?
Example
Conversion of 6.5 km to m
Practice Problem-complete on note-taker
435 mL L
Practice Problem-complete on note-taker
5.39 g mg
Measurement tools used in Biology
Reading a Meter Stick
Meter Stick – major scale division represent centimeters
Each cm is further divided into minor scale divisions-0.1 cm or 1 mm divisions
Reading volume in a graduated cylinder
• Graduated cylinder is marked off in equal units of volumes
• Usually they are graduated in mLs
• Most graduated cylinders have– Major scale divisions –
associated with numbers– Minor scale divisions
between the numbers
• Read the volume at the bottom of the meniscus
Use of balance for determining massIn this class, an electronic balance will be used for measuring mass
Zero the balance by hitting the Tare button before each measurement
Place object on stainless steel tray
Read the value for massIf you get the tray dirty,
please clean it off
Closure Activity
Name two measurement tools discussed in the notes today and explain how they are used in measurement.
Measurement Lab
Constructing well organized Data Tables
Example of a Good Data Table-
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Date Height in cm of plant
Appearance of leaves
4/5/11 10 Leaves are green and there are 2 areas of light green new leaves
4/6/11 10 All leaves are green and there are 3 areas of light green new growth
4/7/11 11 The plant has 3 areas with light green leaves. The leaves appear to be larger
4/8/11 13 Plant is more spread out and has 5 areas of light green leaves
4/9/11 16 Plant has 5 areas of light green leaves
Effect of fertilizer on plants
TThinkhink-P-Pairair-S-SharehareExamine the example data
table. Write down key characteristics of a data table on your note-taker.
Share with a partner3
Data table characteristics
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• Title• Clear labels• Dates• Column/row labels• Units are included• Easy to view• Straight lines• All data can be displayed
PROPERTY OF PIMA COUNTY JTED, 2010 24
Minute Paper- think back to Minute Paper- think back to the bellworkthe bellworkYou have one minute to write down qualitative and quantitative data in the form of a data table that you might take on the new species of plant
Be prepared to share.