Tools And Procedures Flashcards
Why do scientists need a common system of measurement
Researchers need to replicate each other’s experiments and most experiments involve measurements.
When collecting data and doing experiments, what system of measurements do most scientists use.
International system of units/metric system
What is the metric system?
A decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of 10.
1000 meters =
1 kilometer
1 liter=
1000 milliliters
1000 kilograms=
1 metric ton
When scientists collect data, what are they 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?
Pattern
What are microscopes?
Devices that produce magnified images of structures that are too small to see with a naked eye
What are compound light microscopes?
They all light to pass through the specimen and use 2 lenses to form an image.
How to chemical stains make light microscopes more useful?
They show specific structures of the cell.
Fluorescent dyes are combined with video camera and computer processing produce 3D images(cell movement)
What are the 2 main types of electron microscope?
Transmission electron microscope
Scanning electron microscope
Compare how TEM and SEM produce images
TEM- shine beam of electrons through a then specimens. Images show the inside.
SEM- scan a narrow beam of electrons back and forth accords the surface of a specimen. Image shows outside scan.
TEM- detail
SEM- realistic 3D
How must samples be prepared for observations by an electron microscope?
be preserved and dehydrated before placed inside the microscope
Cell culture
A group of cells grown in a nutrient solution from a single original cell
