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G7 ch1.3 exploring life
The development of the microscope allowed scientists to observe microorganisms and cells, changing beliefs about disease causation. Robert Hooke and Anton van Leeuwenhoek used early microscopes to observe cells and microorganisms in the 1600s-1700s. Modern microscopes like light microscopes and electron microscopes provide higher magnification and resolution to observe living and non-living microscopic structures.
G7 ch1.3 exploring life
- 1. Exploring Life CHAPTER 1LESSON 3 – P. 27-31
- 2. Key Concepts • Howdid microscopes change our ideas about living things? • What are the types of microscopes, and how do they compare?
- 3. Vocabulary • Light microscope •Compound microscope • Electron microscope
- 4. The Development ofMicroscopes • The development of the microscope was crucial for understanding disease and pathogens, the causes of diseases. • Between 1600-1800s many people didn’t believe in pathogens, microbes that cause illness. • t took almost 200 years after the Anton van Leeuwenhoek saw the first microorganisms for the concept of spontaneous generation to die out.
- 5. Robert Hooke • Firstperson to see cells and coined the term “cell” • 1665
- 6. Anton van Leeuwenhoek •Dutch merchant and lens grinder • He is called the “Father of Microbiology” • He was able to make simple microscopes that could magnify an object up to 270x. • He was the first person to discover blood cells and microorganisms. • 1674
- 7. Types of Microscopes ONECHARACTERISTIC OF ALL MICROSCOPES IS THAT MY MAGNIFY OBJECTS. WHAT DOES IT MEAN WHEN SOMETHING IS MAGNIFIED?
- 8.
- 9. Resolution • Magnification ishow many times larger the object appears than its original size. • For example, if I am looking at a 1mm long bug that appears 2mm long under the microscope. The magnification of the microscope is 2x.
- 10. Resolution • Resolution ishow clear an object looks under a microscope. • For example, if you put an ant under a microscope that has 10x magnification and you can’t see its legs the resolution of that microscope is poor.
- 11. Characteristics of amicroscope • There are 2 main types of microscopes, light microscopes and electron microscopes. Both differ by magnification and resolution.
- 12. Light Microscopes • Lightmicroscopes use light and lenses to enlarge an image of an object. • If a light microscope uses more than one lens it is a compound microscope. • If a light microscope uses one lens, its simple. Total Magnification = ocular lens x objective lens
- 13. Light Microscopes Light microscopescan enlarge images up to 1500 times the original size. ◦The resolution of a light microscope is about 0.2 micrometers or 2/1,000,000 of a meter. ◦This means if to points are 0.2 micrometers apart you can see the space between them. Light microscopes can be used to see living and nonliving things. ◦They must be mounted on a slide. ◦Some objects must be stained such as white blood cells.
- 14. Electron Microscopes AreAwesome! Electron microscopes use a magnetic field to focus a beam of electrons through an object or onto an object’s surface. ◦Can magnify up to 100,000x ◦Resolution 0.2nanometers or 2/1,000,000,000 meter ◦1,000 times better than a light microscope The Electron Microscope
- 15. TEM (transmission electronmicroscope) Used to see tiny things like cell structures. ◦Preparation is hard ◦Objects are mounted in plastic and thinly sliced ◦Only see dead organisms ◦Electrons pass through the object and the computer makes an image ◦Cost: $250,000 (7,500,000 NT)
- 17. SEM (scanning electronmicroscope) Used to study an objects surface Electrons bounce off the object and a computer produces a 3-D image Can be used to see living things Cost: $500,000 (15,000,000 NT)
- 38. Using Microscopes Health Care ◦Surgery ◦Analyzeblood, urine and other fluids ◦Examine healthy and diseased tissue ◦Display surgery Other Uses ◦Forensic science to study evidence at crime scenes ◦Identifying mold or insects from an idea ◦Paleontologist and palynology examining fossils ◦Industry ◦Steel factories to check for impurities ◦Jewels for scratches
- 39. What would youuse? 1. You study the shape of different minerals. 2. You study the structures inside microorganisms. 3. You study the way a type of pond microbe moves around. 4. You are counting the number of white blood cells a person has. 5. You need to know the different structures and shapes of pollen.