Transcript Cell Diversity - Cloudfront.net

• All life is made of
cells
• Cells discovered after
microscope invented
• 1665: Robert Hooke
first observed cork
(dead tree bark)
– Boxes he saw
reminded him of tiny
rooms
– He named the empty
boxes “cells”
• Three Parts:
– 1) All organisms are
made of cells
– 2) The cell is the most
basic unit of life
– 3) Cells come from other
cells
• What’s the big problem
with this theory?
Where did the 1st ever cell come from?
Cell Diversity
• Shape depends upon function
• Nerve Shape: Elongated branching
– Function: Sends messages to and from brain
• Red Blood Shape: Disc-like shape prevents clogging
– Function: Carries O2 throughout blood
• Skin Shape: Flat & broad; layers overlap
– Function: Covers and protects the body
• 1) Prokaryote: Cells without a nucleus and other
membrane-bound organelles
– First cells/life on Earth (oldest fossils = ~3.6 b.y.o)
– AKA: Bacteria
• 2) Eukaryote: Cells
with a nucleus &
membrane bound
organelles
– More complex cells
– Evolved from
prokaryotes
– Ex: Protists, Fungi,
Plants, Animals
Prokaryotes vs. Eukaryotes
• Endosymbiosis Theory: Chloroplast & mitochondria were freeliving organisms
– Both were engulfed by a larger predator cell
– Both gave the larger cell an advantage (make food and energy)
– Predator cell provided each protection
• Over time, these cells could not survive without the mitochondria
& chloroplast
• Evidence: Mitochondria & chloroplast contain own DNA,
replicate, contain own ribosomes
Kobe Kuiz
1)
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3)
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9)
Who first identified cells?
What was he/she examining?
Name the three parts to the cell theory.
Explain how the shape of a blood cell allows it to
perform it’s job better.
Which category of cells contain nuclei?
Why are bacteria considered the oldest forms of
life on Earth?
How do prokaryotes and eukaryotes differ?
Which organelles are associated with the
endosymbiosis theory?
What evidence exists that the organelles from #8
were once free-living?