BELL RINGER 8-13-14
1.
A prediction or statement that can be tested is a(n) ______.
a.
b.
c.
d.
2.
A sample that is treated exactly like the other experimental groups
except that the variable is not applied to it is a(n) __________.
a.
b.
c.
d.
3.
Conclusion
Observation
Control
Hypothesis
Observation
Variable
Control
Hypothesis
What is the only difference between the control group and the
experimental group in a controlled experiment?
a.
b.
c.
d.
The test
The prediction
The variable
The hypothesis
AGENDA
Standard
Cell Theory Notes
Endosymbiotic Theory Video
Eukaryotic/Prokaryotic Venn Diagram
Independent
Whole class
STANDARD
Students will analyze the nature of the
relationships between structures and functions in
living cells
Explain the role of cell organelles for both
prokaryotic and eukaryotic cells, including the cell
membrane, in maintaining homeostasis and cell
reproduction.
BEFORE WE GET GOING…
A theory in everyday language implies that
something is unproven or speculative
A theory in science is
A widely accepted explanation of things observed in
nature
It must be supported by evidence (including
evidence gained through experimentation and
observation)
CELL THEORY
Some random cell facts:
The average human being is composed of around 100
Trillion individual cells
It would take as many as 50 cells to cover the area of a dot
on the letter “i”
Red blood cells
DISCOVERY OF CELLS
1665 – English scientist, Robert Hooke,
discovered cells while looking at a thin slice
of cork.
He described the cells as tiny boxes or a
honeycomb
He thought that cells only existed in plants and
fungi
ANTON VAN LEUWENHOEK
1673 – used a handmade microscope to
observe pond scum and discovered single-celled
organisms
He called them “animalcules”
He also observed blood cells from fish, birds, frogs,
dogs, and humans
Therefore, it was known that cells are found in
animals as well as plants
150-200 YEAR GAP?
Between the Hooke/Leuwenhoek discoveries and the
mid 19th century, very little cell advancements were
made.
This is probably due to the widely accepted traditional
belief in “spontaneous generation”
Example
Maggots from rotting meat
MATTHIAS SCHLEIDEN
1838 – concluded that all plant parts are made of cells
He was a German botanist
THEODOR SCHWANN
1839 – concluded that all animal tissues are composed of
cells
He was a German physiologist and close friend of
Schleiden
LOUIS PASTEUR
1859 - Disproved spontaneous generation
RUDOLF VIRCHOW
1858 – studied cellular pathology and concluded that
cells must arise from preexisting cells
“Where a cell exists, there must have been a preexisting cell.”
He was a German physician
THE CELL THEORY
3 Basic Components:
All organisms are composed of one or more cells.
The cells is the basic unit of life in all living things.
All cells are produced by the division of preexisting cells.
Roundworm embryo
undergoing cell
division
THE MODERN INTERPRETATION OF CELL THEORY
All known living things are made up of one or more cells
All living cells arise from preexisting cells through division
The cell is the fundamental unit of structure and function
in all living organisms
The activity of an organism depends on the total activity of
independent cells
Energy flow occurs within cells
Cells contain hereditary information which is passed from
cell to cell during cell division
All cells are basically the same in chemical composition in
organisms of similar species
WHY IS CELL THEORY IMPORTANT?
Helps us to differentiate between living and non-living
things.
Unifies all living things – no matter how different one
organism is from the next they are both composed of cells
Foundational for biology!
Mouse kidney cells
Onion cells
PROKARYOTES
The first organisms on Earth
May have lived 3.5 billion years ago and for millions of
years they were the only organisms on Earth
Eukaryotes evolved from prokaryotes, but how?
Endosymbiotic theory
E. coli, prokaryote
Amoeba, eukaryote
PROKARYOTIC/EUKARYOTIC VENN DIAGRAM
Use Chapter 7 in your textbook to complete a Venn
Diagram comparing and contrasting prokaryotic and
eukaryotic cells
Work for 20-25 minutes on your own, then we will fill out a
class Venn diagram based on your input
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