Download The basic unit of life

The Cell
The basic unit of life
Cell Theory: states the following
3 things
1) all living things are
cellular
2) cells are the smallest
functioning unit in all
living things and
3) cells come from preexisting cells
This knowledge came out of the
following work:
• Hans Janssen- 1590, 1st compound microscope
• Robert Hooke -1665, First to use the word “cell”, could
only see cell wall of cork.
• Anton van Leeuwenhoek- 1680, First to observe living
cells (teeth scrapings). He called them “animalcules”.
• Matthias Schleiden-1838, First to observe that plants
are made of cells
• Theodor Schwann-1839, First to put concept that all
living things are cellular
• Rudolph Virchow-1855, Discovered that cells come
from other cells, discredited “spontaneous generation”
(Redi too!)
What’s the fuss?
• People thought that life spontaneously
generated if the substances of life were
present. Not a miraculous process!
2 main types of cells
Prokaryotes
Eukaryotes
No Nucleus or other
membrane-bound
organelles
Contains a nucleus and
other membrane-bound
organelles
Smaller in overall size
Larger in overall size
Cell wall (when present)
contains peptidoglycan,
complex
Cell wall when present
contains cellulose, simpler
Circular DNA
Helical, linear, double
stranded DNA
EX: Bacteria
Ex: Human cells, plant cells
The prokaryote
Fimbriae
Cillia
Location of
DNA/RNA
Cellular movement
• 3 ways cells move (if they can)
Cilia- hair-like projections
Flagella- whip-like projections
Pseudopod-false foot, like the
blob!
The 2 energy organelles
Comparing plant and animal cells
Cell Wall
Plastids
Shape
Vacuoles
Centrioles
Division
Plant
Animal
Present
Absent
Present
Absent
Generally more
Generally more
rectangular due to spherical due to
ridgid cell wall
lack of cell wall
One large
Absent
Build Cell Plate
Many small
Present
Lack cell plate
Once you have one cell….
Individuals cells can, at times, organize themselves to
eventually become multi-cellular organisms. List
the 6 levels of organization from simple to
complex.