Tools_of_the_Biologist.ppt slides presentation
- 1. Tools of the Biologist
- 2. In order to observe, discover, and explore, scientists use many different pieces of lab equipment. A. Measuring Length 1. Meter stick, Ruler Each marked line represents 1 cm. The smaller lines between cm are mm. There are 10 mm in 1 cm There are 100 cm in 1 m
- 3. B. Measuring Volume 1. Graduated Cylinder Used to measure exact volumes To Use: Fill to the appropriate level. Note that liquid in a glass graduate cylinder curves upward at the edges. This is called the MENISCUS. Read the volume at the bottom of the meniscus when looking at eye level.
- 5. 12 mL 16 mL 14 mL 14 mL Pay attention to the scale of the graduate cylinder (How much the lines go up by)
- 6. B. Measuring Volume 2. Beaker Used to measure a approximate volume To use: fill with the appropriate volume There will not be much of a meniscus Read at eye level.
- 7. B. Measuring Volume 3. Erlenmeyer and Florence Flasks Used to measure an approximate volume And/or to mix solutions To use: same as beaker Erlenmeyer Florence
- 8. B. Measuring Volume 4. Pipette Used to measure an approximate volume Measures one drop at a time To use: (to fill) submerge, gently squeeze and release (to release) carefully squeeze 1 drop at a time
- 9. C. Measuring Mass 4. Electronic Balance Used to measure an exact mass To use: Turn on, zero the balance, set to correct unit, carefully place sample on tray. If sample is placed in a container subtract the mass of the container from the total mass
- 10. D. Tools for Dissection 1. Dissecting Pan Used to hold specimens in place To use: Lay the specimen on the tray and pin to the rubber bottom
- 11. D. Tools for Dissection 2. Dissecting Needle (Probe) Multi-purpose tools to move parts of the specimen
- 12. D. Tools for Dissection 3. Scalpel Use: to make precision cuts and/or take samples
- 13. D. Tools for Dissection 4. Forceps Use: to grasp and manipulate parts of a specimen
- 14. E. Using Chemicals 1. Test Tube/Test tube rack Use: to carry out chemical reactions When not in use, put in test tube rack
- 15. E. Using Chemicals 1. Test Tube Holder Use: to hold and move test tubes Squeeze handle so the clamp opens Release handles so the clamp closes around test tube
- 16. E. Using Chemicals 1. Test Tube Brush Use: cleans inside of test tube
- 17. F. Observing Specimens and Samples 1. Petri Dish Use: small dish to hold samples and/or grow bacterial samples.
- 18. G. Safety Equipment 1. Safety Goggles Use: Place over your eyes for protection
- 19. G. Safety Equipment 1. Safety Gloves Use: Place over your hands for protection from heat, chemicals, body fluids, etc
- 20. G. Observation 1. Compound Light Microscope Use: enlargement of microscopic specimens
- 22. 1. Compound Light Microscope - Magnifies specimen 100s of times - “Compound” means it has several lenses 2. How to Use a Microscope - Always carry the microscope by the arm while supporting the base - Position the microscope so the arm is near to you - ALWAYS START WITH THE LOWEST POWER MAGNIFICATION
- 23. 2. How to Use a Microscope (cont) - Center the slide on the stage - Center the specimen in the field of view (remember the image is inverted) - Use the coarse adjustment to focus the slide - - Once the slide is in focus, switch to a higher power then refocus with fine adjustment - ONLY USE THE FINE ADJUSTEMENT ONCE YOU’VE SWITCHED TO THE HIGH POWER LENS – IF NOT THE SLIDE WILL CRACK
- 24. Making a Wet Mount Slide Wet mounts are microscope slides that contain a specimen mounted in water. A cover slip (or cover glass) is used to flatten the specimen and the water drop. 1. Obtain a clean microscope slide and cover slip. Hold cover slips only by the edges. 2. Add a small drop of water to the slide. 3. Place the specimen in the drop of water. 4. Hold the cover slip at a 45˚ angle next to the drop of water, slide it over until it hits the water. Place it onto the water. This helps prevent air bubbles.
- 25. Adding a Stain/Chemical to Wet Mount Slide Stains: Chemicals added to a slide in order to see parts of a specimen more clearly.
- 27. Adding a Stain/Chemical to Wet Mount Slide Stains: Chemicals added to a slide in order to see parts of a specimen more clearly. 1. After making a wet mount slide, place a drop of stain on one side of the cover slip 2. Gently touch the other side of the cover slip with a piece of paper towel 3. The paper towel will “pull” the stain under the coverslip
- 29. Human Red Blood Cells
- 30. Plant Cells Fly Head Sperm Cells Pollen
- 31. Cancer Cells Whooping Cough E Coli