7-1 Life is CELLULAR
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Transcript of 7-1 Life is CELLULAR
7-1 Life is CELLULAR
Federoff
Key Questions
• What is the cell theory?• How do microscopes work?• How are prokaryotic and eukaryotic cells
different?
Discovery of the Cell• Microscopes allowed a new
world to open up.– Started in the late 1500’s with
eyeglass makers• Robert Hooke (1665)– Englishman– Studied Cork – Termed cells “cells” because of
their resemblance to monastery rooms.
Discovery of the Cell (cont.)
• Anton van Leewenhoek– Same time as Hooke– Documented first LIVING and moving cells we
know today as microorganisms
Cell Theory• Schleiden, Schwann and Virchow – Scientists contributors
• States that:– All living things are made of cells– Cells are the basic structure and function in all living things– New cells come from existing cells
Exploring the cell - Microscopes
• Light Microscopes– Have an objective and eyepiece (ocular) lens– Compound magnification– LIMITS• Detail• 1000x magnification• Requires a stain• Thin specimen for light to pass through
Microscopes (cont.)
• Electron Microscopes– Higher Resolution– Can view DNA and Viruses– Scanning and Transmission– LIMITS• Must chemically preserve• Needs to be DEAD• Need to add false color
Scanning
Transmission
Cell Types
• Lots of variety in size, shape and function• All contain DNA and a cell membrane• 2 Types– Eukaryotes – have DNA in a nucleus– Prokaryotes – Do not have a nucleus to contain
their DNA
Prokaryotes• Smaller• Simpler• Doesn’t separate DNA with a nucleus• Unicellular• Ex. Bacteria
Eukaryotes
• Larger• More complex• DNA in nucleus• Great variety• Unicellular or Multicellular• Ex. Your cells