Tools of Science EQ: How do we quantify our observations?

The Metric System Based on a scale of 10 –Units are 10 times more or less than the one you started with Also called the International System of Units (SI) –Almost all countries use it as their everyday means of measurement –United States has tried converting in the early 1980’s but met with resistance from the older generation

Metric Mnemonic K H D B D C M King Henry Died BY Drinking Chocolate Milk

2 nd Way to Convert in Metric

Common Metric Units Length is measured in meters using a ruler or odometer Mass is measured in grams using a scale Temperature is measured in Celsius using a thermometer Volume is measured in liters using a graduated cylinder –There is also a math calculation for mass which is length times width time depth –cm 3

Light Microscope Magnifies something too small to see with the naked eye by focusing light rays Can magnify the image up to 1000 times

Basic Rules for Using a Microscope Always carry a microscope with 2 hands –One on the arm, one on the base Always start on the lowest objective lens and finish on the lowest lens Course adjust only on the lowest power –Always fine adjust on medium and high power!!! Turn the light off when done

Electron Microscope Developed to see very small objects – like the organelles in a cell Magnifies objects by focusing beams of electrons Scanning electron microscopes are capable of producing a three dimensional image of an object Can only be used on dead organisms

Cell Cultures A way of taking a single living cell and having it reproduce under controlled conditions This enables the scientists to have large numbers of cells to study

Cell Fractionation Used to separate different parts of the cell from the whole Cells are first broken down and then spun The parts separate based on their density –The lighter parts stay suspended in the water –The heavier parts sink to the bottom Biologist can choose which layer to study