Transcript 2. Cell Theory - Hicksville Public Schools / Homepage

LO: SWBAT explain how the cell
theory was developed
Do Now: What instrument was vital
for scientists to discover and learn
about cells? How does this
instrument work?
HW: Read pages 169-172, page
172 # 1-5
What instrument was vital for
scientists to discover and learn
about cells?
A light microscope can
magnify objects
up to 1000 times.
This instrument allows scientists
to see larger parts of a cell (cell
membrane, nucleus,
chromosomes, etc…)
Light Microscope
Anton van Leeuwenhoek
1600’s
Spiral Bacteria
Developed simple light
microscopes that allowed him to
examine tiny living organisms
he called “animacules”
Human Sperm
Robert Hooke(1665)
What is this?
First Compound
Microscope
CORK CELLS
First person to use the word
“cell”
Matthias Schleiden (1838)
ALL PLANTS ARE MADE OF
CELLS
Theodor Schwann (1838)
ALL ANIMALS ARE MADE UP OF
CELLS
Rudolf Virchow (1858)
CELLS COME FROM
PRE-EXISTING CELLS
How the Cell Theory was developed
Cell theory
• All living things are made of
cells
• Cells are the basic unit of
structure and function
(metabolism)
• New cells come from preexisting cells
What are some problems with
the Cell Theory?
• Are viruses living?
• Where did the first cell come
from?
Viruses
They are not made up of
cells, but are they living?
What do you know about
viruses?
•They can make
you very sick
•They can be
transmitted
from person to
person
•There are
different types
of viruses
HOW BIG IS A VIRUS?
Too small to be seen with a
light microscope
They are
microscopic and
smaller than
cells!
How can we determine if a
virus is living or non-living?
•
•
•
•
Is it made of cells?
Does it maintain homeostasis?
Does it carry out metabolism?
Does it reproduce?
Is a virus living or non
living?
How a Virus works
How are cells
classified?
How do these cells compare?
Cells are broken down into two
main classes:
Cells
Prokaryotic
Eukaryotic
Prokaryotes:
Were probably the first life forms
to appear on earth 3.5 billion
years ago
What were the conditions o
Earth at this time?
1)Hot
2)Little Oxygen
3)Abundant Lightning
4) Volcanic Activity
Harsh Early Earth
Why do you think Prokaryotes
were the first life forms on
earth?
1)Simple Structures
2) Their ability to
tolerate harsh
environments
3) Their ability to adapt
to changing
environments
What are some features of
prokaryotes?
** Although
prokaryotes do not
have nuclei, they
do have DNA.
1)Prokaryotes have NO NUCLEUS!!
2) Have few organelles (mini-organs)
3) PROKARYOTES = BACTERIA
What organisms are made up of
eukaryotic cells?
Plants
Animals
Fungi
Protists
All other living things are made up of
Eukaryotic Cells
What are some features of
typical eukaryotic cells?
1) They are more
complex
2) Appeared later on
earth
3) They have nuclei
4) They are larger
5) Have more organelles
6) Have membrane
bound
organelles
Eukaryotes
CELL TYPES
• PROKARYOTIC •
• HAVE only a few •
•
ORGANELLES
•
• HAVE NO
NUCLEUS
•
• PRIMITIVE CELLS
• Only Bacteria
EUKARYOTIC
HAVE ORGANELLES
HAVE NUCLEUS
MODERN CELLS
All other living
things: animals,
plants, fungi, protist
(unicellular
organisms)
What do all cells have in
common?
• Cell membrane –
gives shape to the
cells and allows
things in and out.
• The cytoplasm –
the jelly like
material where all
cell parts are
found
Compare and contrast
these two cars?
How Do
These Cells
Compare?
Eukaryotes
evolved from
prokaryotes