Unit C: Cycling of Matter in Living Systems Science 10 Unit C: Cycling of Matter in Living Systems

C1.1 Microscopy: A Window on a new World

Aristotle Aristotle is known as “The Father of Biology.” He was one of the first Greek philosophers who used the Scientific Method of observing, recording, reasoning, and interpreting in attempt to explain the world around him.

Microscopes Timeline 3000 years ago: Egypt & Mesopotamia Glass – the material for lenses Early 1200s: Roger Bacon Described how crystal lenses might improve vision of the elderly

Microscopes Timeline Late 1200s: Salvino degli Amati (Italy) Made the first pair of spectacles Lenses were fashioned by craftsmen A new branch of physics, called optics, was born to explain the movement of light

Microscopes Timeline 1600s: Telescopes & Microscopes 1595 Hans and Zacharias Janssen (Holland) invent the first 2-lens compound light microscope 1665 Robert Hooke (England) developed a 3-lens system. Hooke observed thin slices of cork and saw what he called cells 1665 Antoni van Leeuwenhoek, an expert lens crafter was the first to reveal the microbial world His daughter helped him make his microscopes They were the first to see the movement of different types of cells we now call protozoa, sperm, and bacteria

Microscope by Hans and Zacharias Janssen

Figure C1.3 Hooke’s Mircroscope

Human Immunodeficiency Virus (HIV) As lens technology improved over the years, the world’s knowledge of the microscopic world increased, allowing us to solve many problems Red Blood Cells Human Immunodeficiency Virus (HIV) E. Coli bacteria cluser

Using Microscopes A MICROSCOPE is an instrument with a lens or system of lenses for magnifying specimens. In order to use a microscope you must be familiar with the following: Microscope Structures & Functions Microscope Handling Protocol Calculating Magnification Unit Conversion Field of View

Eye Piece or Ocular Lens. Coarse Focus Adjustment Arm Stage Clip Fine Focus Adjustment Base Lamp Diaphragm Stage Objective Lenses Revolving Nosepiece Body Tube

Handling A Microscope Always carry the microscope in an upright position with two hands: one on the base, the other on the arm. Use only lens paper to clean lenses. Make sure the power switch is off before you plug it in. Never allow the lens to touch the slide. Never attempt to repair the microscope yourself.

Use stage clips to hold the slide steady. Always start to focus on the low-power objective lens first. Use the coarse focus first. Never use the coarse focus on the high-power objective lens. When you are finished: Rotate to the low-power objective lens Remove the slide Turn the microscope off Put the dust cover on Remove the power cord from the socket by the plug.

Calculating Magnification The MAGNIFICATION tells the reader how much larger (or smaller) the picture is than the real size of the item In order to calculate the magnification of a system use the following formula:

Skill Practice pg. 244 Calculating Magnification What is the magnification if the following combinations of lenses are used? a) A 2.5X low-power objective lens and a 10X ocular lens? 25X b) A 100X high-power objective lens and a 10X ocular lens? 1000X

Equivalent Measurement Unit Conversion Line Master 1: Units of Measurement Unit Equivalent Measurement Centimetre (cm) 1/100 metre; 10–2 m Millimetre (mm) 1/10 centimetre; 10–3 m Micrometre—also known as the Micron (μm) 1/1000 millimetre; 10–6 m Nanometre (nm) 1/1000 micrometre; 10–9 m Angstrom (Å) 1/10 nanometre; 10–10 m

Skill Practice Complete the following table. 40cm ______μm 1.6 nm Unit Conversion Complete the following table. 40cm ______μm ______ cm 1.6 nm 400 A ______ mm

Field of View The FIELD OF VIEW is the entire area that you see when you look through the microscope. Activity: Look at your partner through a paper towel roll. Now, get your partner to walk closer to you. Do you see more or less of your partner? Does your partner appear larger or smaller when he or she is closer to you? The same idea applies to magnification: Magnification increases the size of what you see BUT decreases the amount of the object in view

Since the field of view decreases in size in direct proportion to the increase of the magnification, we can calculate the size of the other fields of view. For example: If the field of view is 4000μ at 40X, it will be 10 times smaller at 400X, or 400μ in size.

Skill Practice Complete the following table: 4000 0.4 400 Calculating Field of View Complete the following table: Lens Magnification Field of view (mm) Field of view (μm) 40 4 100 1.6 1600 400 4000 0.4 400

Assignment Read pp. 242-246 Check & Reflect pg. 246 #1-8 Line Masters 1 & 2