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Scientists rely on a common measurement system to replicate experiments accurately. The metric system, a decimal-based system using units like meters and liters scaled on multiples of 10, is predominantly used for data collection. This system simplifies conversions, such as 1000 meters equaling 1 kilometer. Understanding measurement units is essential for data analysis in biology, aiding in recognizing patterns through graphical representations. Tools like microscopes further enhance our ability to study minute structures, crucial for biological research and understanding life processes.
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Tools and Procedures Measurements
Why do scientists need a common system of measurement? • .Researchers need to replicate one another’s experiments, and most experiments involve measurements
When collecting data and doing experiments, the system of measurement most scientists use is the ___________________ • MetricSystem
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.
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 ________
Metric System • a. 1000 meters = 1 kilometer • b. 1 liter = 1000 milliliters • c. 1 gram = 1000 milligrams • d. 1000 kilograms = 1 metric ton
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.
What does a graph of data make easier to recognize and understand than a table of data? • A pattern
Microscopes • What are microscopes? • Microscopes are devices that produce magnified images of structures that are too small to see with the unaided eye.
What are compound light microscopes? • They are microscopes that allow light to passthrough the specimen and use two lenses to form an image.
How do chemical stains make light microscopes more useful? • They can show specific structures in the cell.
What are the two main types of electron microscopes? • a. Transmission electron microscopes (TEMs) • b. Scanning electron microscopes (SEMs
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. • .
How must samples be prepared for observation by an electron microscope? • Samples must be preserved and dehydrated
Laboratory Techniques • A group of cells grown in a nutrient solution from a single original cell is called a ____. • Culture
What technique do biologists use to separate one part of a cell from the rest of the cell? • cell fractionation
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.
A device that produces magnified images of structures that are too small to see with the unaided eye • microscope
A well-tested explanation that unifies a broad range ofobservations • theory
The process by which organisms keep their internalconditions fairly constant • homeostasis
An organized way of using evidence to learn aboutthe natural world • science
The chemical reactions through which an organismbuilds up or breaks down materials • metabolism
A collection of living matter enclosed by a barrier thatseparates it from the surroundings • cell
