Download Science 10 Section I: Intro to Cell Theory

•Looked
at a cork and it reminded him of a
‘cell’ of a Monastery.
•He called them the building blocks of life.
“ALL LIVING THINGS ARE
MADE OF CELLS AND
CELL PRODUCTS”



Early scientists had trouble understanding the
origins of living things. They believe in the
theory of ‘spontaneous generation’ whereby
living things could emerge from non-living
matter.
For example, flies or rats could be created
from rotting garbage.
Louis Pasteur put an end to this theory and
suggest that ONLY LIVING THINGS COULD
COME FROM LIVING THINGS!


Rudolf Virchow refined Pasteur’s idea into a
new theory.
EVERY CELL
COMES FROM A CELL
Virchow’s Theory:




Virchow’s theory suggests that we all have a
touch of immortality.
The cells in your body come from genetic
information passed down to you by your
parents, ancestors and so on…
Part of you has been alive since the very first
human!!!
We accept Virchow’s theory as ‘true for now.’





Cells are unicellular and multicellular
Size from 5 to 50 Microns: piece of paper is
75 microns (millionths of a metre)
Cell shapes include: cubes, spheres,
doughnuts, columns, balloons, rods,
pancakes, hearts, corkscrews, etc…
Humans have on average 100 Trillion cells
155,000 cells in cm3


Brain has 30 billion brain cells! You cannot
grow more.
Your blood has 20 trillion red blood cells.

2 KINDS of cells:
1) PROKARYOTIC: this type of cell has no
nucleus or membrane bound organelles
within it. Genetic material is spread
throughout the cell.


Examples: BACTERIA and ALGAE
Sometimes these cells are called MONERANS



2) EUKARYOTIC: All other living organisms
(plants, animals, fungi and protists) are
composed of eukaryotic cells.
These cells have a nucleus and membrane
bound organelles.
There are many organelles inside a cell that
we can look at further.