Chapter 1 - The Science of Biology 1-4 Tools and Procedures METRIC

1-4 tools & Procedures A common Measurement System Analyzing Biological data

Why do scientists need a common system of measurements? What is this common system called? What types of measurements are made in an experiment? To replicate one another’s experiments The Metric System S.I. Systeme Internationale It is a decimal system of measurements Length Mass Volume Temperature

Length This is the distance of something from end to end. Measured in METERS

There are 10 millimeters in one centimeter The system is based on multiples of 10

Mass How much matter is in an object Measured in GRAMS

Volume How much space an object takes up Measured in LITERS (liquid) Measured in cubic centimeters

The presence or absence of heat Temperature The presence or absence of heat Measured in CELSIUSo Water boils Water freezes

Metric System Category Definition Measured in: Length This is the distance of something from end to end Meters millimeters centimeters Volume How much space an object takes up Liters milliliters Mass How much matter is in an object (heavy) Grams milligrams Temperature The presence or absence of heat Celsius degrees 0o - freezing 100o boiling

Uncertainty of Measurements Lab Using metric tools, you will Measure length and width in cm and mm. Measure mass with grams. Measure volume by water displacement (uneven object) and LxWxH (even object) Measure temperature with a Celsius thermometer

Station 1 Meter stick to measure table top area

Estimate length using a metric ruler

Estimate length using a metric ruler

Estimate length with a metric ruler

Station 2 Metric ruler to measure a regular object’s volume

Station 3 Graduated Cylinder used to measure the volume of a colored liquid Meniscus

Estimate volume in a graduated cylinder

Estimate volume in a graduated cylinder

Station 4 Mass: (of an irregular object) Triple Beam Balance

Gages are all locked at the left Balanced is at ZERO

Mass Move gages to determine weight Start with smallest gage first Mass/weight is determined when it is balanced

Irregular pebble

Triple beam measurement

Triple beam balance

Triple beam balance

Station 5 Graduated Cylinder to find the volume of an irregular object 265 ml After 200 ml Before 265ml (after) -200ml (before) V(pebble) = 65 ml

Station 6 Celsius Thermometer to find the temperature of ice water Never allow the thermometer to touch the glass at the bottom

Gathering data from 9 other groups: Will there be inconsistent results?

Analysis & Conclusion

Cornell notes for 1-4 Like we did before, lets write down questions on the left side of our notebook and leave space on the right side for your answers. Each group will be assigned a question according to the number on their desk. You will be given 5 minutes to find your answers then you will share them with the class.

1-4 Questions What is a light microscope? What is an electron microscope? What is a Scanning Electron Microscope? What is a Transmission Electron Microscope? How are light microscopes and electron microscopes the same?

Questions (cont) How are light and electron microscopes different? What is a cell culture? What is cell fractionation?

Let’s see how we did on our answers!

TOOLS Light Microscope Produce magnified images by focusing visible light rays Produce images up to 1000X normal size Stains and dyes show specific structures in cells

Electron Microscope Use beams of electrons (rather than light) to produce images. Can produce images about 1000 times more detailed than a light microscope.

2 types of electron microscopes: Scanning Electron Microscopes Get 3-Dimensional views Like this 3-D view of pollen Transmission Electron Microscope Get views of thin slices Like this cell part

How are light and electron microscopes different? They are different in 2 ways: 1. Light microscope magnifies by using focused light Electron microscope magnifies by using electrons 2. Light microscopes can view live specimens Electron microscopes can only view dead specimens because the electrons operate in a vacuum with no air.

A single cell is placed into a petri dish and allowed to reproduce many more cells. This gives scientists enough material to study Cell parts are separated by spinning rapidly in a centrifuge Homework: P. 28 # 1,2,3,4,5 Workbook p. 10,11,12 LABORATORY TECHNIQUES Cell Cultures Cell Fractionation

1-4 HOT Questions List the 4 common metric units. Describe the main difference between the metric system and the English system of measurement. Sequence the following units in order from smallest to largest: m, mm, km, cm. Conclude why it is important to zero out a triple beam balance or an electric scale before you weigh an object. Justify why we wear goggles in the lab when using chemicals.

1-4 Homework p. 28 # 1, 2, 3, 4, 5 p. 31 # 22, 23