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Tools and Procedures

Tools and Procedures . Measurements. A Common Measurement System . Why do scientists need a common system of measurement? . . Researchers need to replicate one another’s experiments, and most experiments involve measurements.

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Tools and Procedures

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  1. Tools and Procedures Measurements

  2. A Common Measurement System

  3. Why do scientists need a common system of measurement? • .Researchers need to replicate one another’s experiments, and most experiments involve measurements

  4. When collecting data and doing experiments, the system of measurement most scientists use is the ___________________ • MetricSystem

  5. What is the metric system? • The metric system is a decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of 10.

  6. Give the correct number or metric unit for the following: • a. 1000 meters = 1 ____ • b. 1 liter =___ milliliters • c. 1 gram = ______milligrams • d. 1000 kilograms = 1 ________

  7. Metric System • a. 1000 meters = 1 kilometer • b. 1 liter = 1000 milliliters • c. 1 gram = 1000 milligrams • d. 1000 kilograms = 1 metric ton

  8. Analyzing Biological Data

  9. When scientists collect data, what are they often trying to find out? • They are trying to find out whether certain factors changed or remained the same.

  10. What does a graph of data make easier to recognize and understand than a table of data? • A pattern

  11. Microscopes • What are microscopes? • Microscopes are devices that produce magnified images of structures that are too small to see with the unaided eye.

  12. What are compound light microscopes? • They are microscopes that allow light to passthrough the specimen and use two lenses to form an image.

  13. How do chemical stains make light microscopes more useful? • They can show specific structures in the cell.

  14. What are the two main types of electron microscopes? • a. Transmission electron microscopes (TEMs) • b. Scanning electron microscopes (SEMs

  15. Compare how a TEM and an SEM produce images. • A TEM shines a beam of electronsthrough a thin specimen, • whereas an SEM scans a narrow beam of electrons back and forth across the surface of a specimen. • .

  16. How must samples be prepared for observation by an electron microscope? • Samples must be preserved and dehydrated

  17. Laboratory Techniques • A group of cells grown in a nutrient solution from a single original cell is called a ____. • Culture

  18. What technique do biologists use to separate one part of a cell from the rest of the cell? • cell fractionation

  19. What is the single most important rule for your safety while working in a laboratory? • Always follow your teacher’s instructions and the textbook directions exactly.

  20. A device that produces magnified images of structures that are too small to see with the unaided eye • microscope

  21. A well-tested explanation that unifies a broad range ofobservations • theory

  22. Change over timein an organism is to ___. • evolve

  23. The process by which organisms keep their internalconditions fairly constant • homeostasis

  24. An organized way of using evidence to learn aboutthe natural world • science

  25. Evidence gathered from observations • data

  26. The chemical reactions through which an organismbuilds up or breaks down materials • metabolism

  27. A collection of living matter enclosed by a barrier thatseparates it from the surroundings • cell

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