metric, measurement & microscope
DESCRIPTION
Metric, measurement & Microscope. What measurement system do most Scientists use? How are light microscopes and Electron microscopes similar? How are they different?. 1. 2. 3. Meters Liters Grams. How do you use the “ladder” method? . 1 st – Determine your starting point. - PowerPoint PPT PresentationTRANSCRIPT
Metric, measurement &
Microscope
What measurement system do most
Scientists use?
How are light microscopes and Electron microscopes
similar?
How are they different?
KILO1000Units
HECTO100
UnitsDEKA
10Units
DECI0.1
UnitCENTI
0.01Unit
MILLI0.001Unit
MetersLitersGrams
Ladder Method
How do you use the “ladder” method? 1st – Determine your starting point.
2nd – Count the “jumps” to your ending point.
3rd – Move the decimal the same number of jumps in the same direction.
4 km = _________ m
12
3
How many jumps does it take?
Starting Point Ending Point
4.1
__.2
__.3
__. = 4000 m
Try these conversions using the ladder method.
1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm
14 km = _______ m 109 g = _______ kg 250 m = _______ km
Conversion Practice
Compare using <, >, or =.
56 cm 6 m 7 g 698 mg
Length is the distance between two points.
The SI base unit for length is the meter.
We use rulers or meter sticks to find the length of objects.
Length
Analyzing Biological Data
Scientists collect data to find out whether certain factors change or remain the same.
Often, the simplest way to do that is to record the data in a table and then make a graph
Computers help scientists to gather, analyze, and present large quantities of data.
Analyses of data are used to make predictions about complex phenomena.
MicroscopesMicroscopes are devices that produce magnified images of structures that are too small to see with the unaided eye.
Scientists today use Two kinds of microscopes:
Light Electron
A light microscope, also called an optical microscope, is an instrument to observe small objects using visible light and lenses.
Onion Peel Stained animal cheek
cell
The electron microscope is a type of microscope that uses a beam of electrons to create an image of the specimen
House FlyDust mite
In order for a microscope to be useful, there must be two important properties----
magnification and resolution
Magnification is the ability to make things larger than they are
Resolution-the sharpness of an image
What’s my power?To calculate the power of magnification, multiply the power of the ocular lens by the power of the objective.
6 steps of how to view a specimen under a microscope:
1. Turn on the light2. Lower the stage to minimum and click
low objective in3. Slide over light hole4. Focus slide/course adjustment5. Click on high lens6. Focus with fine adjustment
Compound light microscopes• allow light to pass through the specimen
• use two lenses to form an image.
• Light microscopes make it possible to study dead organisms and their parts
• to observe some small organisms and cells while they are still alive.
Laboratory Techniques
• biologists place a single cell into a dish • contains a nutrient solution.
The cell is able to reproduce so that a group of cells, called a cell culture, develops from the single original cell.
Mosquito Cell Culture
Cell cultures can be used to:
• test cell responses under controlled conditions
• study interactions between cells
• select specific cells for further study
Centrifuge
• Cells are broken into pieces in a special blender.
• The broken cell bits are added to a liquid and placed in a tube.
• The tube is inserted into a centrifuge that spins, causing the cell parts to separate, with the most
dense parts settling near the bottom of the tube.
• A biologist can then remove the specific part of the cell to be studied by selecting the
appropriate layer.
