Transcript Origins of Life ETO 2016_Silverman Mod

• Benchmark SC.912.L.15.8
•
Standard 15 Diversity and Evolution of Living Organisms
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Describe the scientific explanations of the origin of life on Earth. Pg. 58
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Benchmark Clarifications
Students will describe scientific explanations of the origin of life on Earth.
Students will identify situations or conditions contributing to the origin of life on Earth.
Students will identify ways in which a scientific claim is evaluated (e.g., through scientific
argumentation, critical and logical thinking, and consideration of alternative explanations).
Students will assess the reliability of sources of information according to scientific standards.
Students will identify what is science, what is not science, and what resembles but fails to meet
the criteria for science.
Content Limits Items may address the conditions required for the origin of life on
Earth but may not require specific knowledge of the age of Earth or its eras, periods, or epochs.
Items may assess how contributions of scientists such as Pasteur, Oparin, Miller and Urey,
Margulis, or Fox aided in the development of the scientific explanation of the origin of life but will
not assess what each scientist contributed.
Items assessing the origin of organic molecules, chemical evolution, and/or eukaryotic cells should
be conceptual.
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http://fcat.fldoe.org/eoc/pdf/BiologyFL11Sp.pdf
Think Ahead
1. One of the accepted scientific theories describing
the origin of life on Earth is known as chemical
evolution. According to this theory, which of the
following events would need to occur first for life to
evolve?
a. onset of photosynthesis
b. origin of genetic material
c. synthesis of organic molecules
d. formation of the plasma membrane
Abiogenesis
• -a living organism arises naturally
from non-living matter.
Spontaneous Generation
Biogenesis, which is the creation of living
organisms by other living organisms.
http://www.divediscover.whoi.edu/biology/light.html#
Deep Sea Vents 3 minutes
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http://www.teachersdomain.org/asset/tdc02_vid_deepseavents/
1. ________________ is the process by which some
organisms use chemical energy to produce
carbohydrates.
a. Photosynthesis
b. Cell Respiration
c. Chemosynthesis
d. Fermentation
The bubble model states that that the key processes
that formed the chemicals needed for life took place
within bubbles beneath the ocean ís surface.
What important role did bubbles play according to the
bubble model?
A. They provided protection from damaging ultraviolet
radiation.
B. They allowed the reactions to take place in the
presence of oxygen.
C. They kept the chemical products from ever entering
Earth’s atmosphere.
D. They gave the activation energy needed for
spontaneous chemical reactions.
How does a scientific law differ from a
scientific theory?
A law is a description of what happens in nature.
They are generally accepted to be true and
universal. Laws often have a mathematical basis.
A theory is based a set of related observations or
events based upon proven hypotheses.
-They are subject to change as new information is available.
• A theory can’t become a law.
*
Support
Video Theory and Law
• One way to tell a law and a theory apart is to
ask if the description gives you a means to
explain 'why'.
• Example: Consider Newton's Law of Gravity.
Newton could use this law to predict the
behavior of a dropped object, but he couldn't
explain why it happened.
http://www.youtube.com/watch?v=zGgIdrD20do
• How does the term,
• “Theory related to the puzzle activity?
Puzzle Activity
Groups of 4
Listen for Instructions
Puzzle Theory Presentation
Origin of Life
3 min.
• https://www.youtube.com/watch?v=XvMgoelauLQ
• The Miller-Urey experiment showed that, under certain
conditions, organic compounds could form from
inorganic molecules. What is one consequence of this
experiment?
• A. The experiment proved that methane and ammonia
will always give rise to organic molecules in any
circumstance.
• B. Scientists think it is possible that organic compounds
formed from the inorganic compounds present on Earth
billions of years ago.
• C. The experiment used the exact inorganic compounds
present on Earth billions of years ago and left little
doubt about the mechanism of early life
Origins of LifeO
SC.912.L.15.8
Where Did Life Originate On Earth?
What is Life?
• First we have to define LIFE…
– composed of cells
– respond to stimuli
– regulate internal processes
• homeostasis
– use energy
• metabolism
– grow and develop
• change & mature within lifetime
-reproduce
• heredity
– DNA / RNA
-evolve
• Adapt to changes
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• Origin of Life Timeline Definitions
Heterotrophic –obtains energy from the food it
consumes. Energy from others.
Autotroph- makes its own food by capturing
energy from sunlight.*Plants.
Eukaryote- multi-cellular organism with
membrane organelles that has a nucleus
Prokaryote- unicellular (single-celled) organism
without a nucleus
• Anaerobic- process that does not require oxygen
• Aerobic- process that requires oxygen
Origin of Life
-Heterotrophs
Prokaryotic
anaerobes
Prokaryotic
aerobes
- Autotrophs
Eukaryotes
Origin of Life Video-Really Good
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http://dsc.discovery.com/tv-shows/curiosity/topics/the-very-first-living-thing.htm
Sci-Method
ProblemHypothesisVariables
-Independent-DependentConclusion-
Francesco Redi
http://www.sumanasinc.com/webcontent/animations/content/scientificmethod.html
How is Pasteur;s experiment
similar to Redi’s?
1. When Pasteur prepared his long curved neck flash
for his experiment, he was trying to disprove which
idea?
a. abiogenesis
b. theory of use and disuse
c. theory of natural selection
d. spontaneous generation
http://exploringorigins.org/timeline.html
Soup to Cells 3 minutes
http://www.goldiesroom.org/Multimedia/Movie_Clips/21%20Evolutio
n/Evolution%20 of%20Cells.wmv
TRUE or FALSE there is only one theory involving the Origin of Life.
Two models of the origin of life on Earth are the
primordial soup model and the bubble model.
What do these two models of how life began on
Earth have in common?
• A. Both explain how UV radiation produces
ammonia and methane.
• B. Both involve only chemical reactions that
take place within the ocean.
• C. Both include chemical reactions that take
place when there is lightning.
• D. Both involve only chemical reactions that
take place within the atmosphere
1500
2000
2500
3000
3500
ARCHEAN
Millions of years ago
1000
Paleozoic
PRECAMBRIAN
500
Cenozoic
Mesozoic
PROTEROZOIC
0
Colonization of land
by animals
Appearance of animals
and land plants
First multicellular
organisms
Bacteria Archae- Protista Plantae
bacteria
Fungi
Animal
Sexual
Reproduction
Diversity
Oldest definite fossils
of eukaryotes
Phylogenic Tree
Appearance of oxygen
in atmosphere
Oldest definite fossils
of prokaryotes
Heterotrophs
4000
Molten-hot surface of
earth becomes cooler
4500
Formation of earth
The evolutionary tree of
life can be documented
with evidence.
* Coacervates
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http://science.discovery.com/tv-shows/greatest-discoveries/videos/100-greatest-discoveries-origin-of-life.htm
• Miller and Urey subjected hydrogen gas,
water vapor, ammonia, and methane gases to
sparks in a reacting chamber.
What was produced, giving support to the
primordial soup model of the origin of life?
A. primitive plants
B. organic compounds
C. single-celled organisms
D. membrane-bound organelles
Origin of Life Sequence
Sequencing Activity
•Place the cut outs /
events in order from
the oldest to the
newest events.
Conditions on early Earth
• Reducing atmosphere
– water vapor (H2O), CO2, N2, NOx, H2, NH3, CH4, H2S
– lots of available H & its electron
– no free oxygen
low O =
2
• Energy source
– lightning, UV radiation,
volcanic
What’s missing
from that
atmosphere?
organic molecules
do not breakdown
as quickly
Origin of Organic Molecules
Electrodes discharge
sparks
(lightning simulation)
• Abiotic synthesis
– 1920 * Coacervates
Oparin & Haldane
propose reducing
atmosphere hypothesis
– 1953
Miller & Urey
test hypothesis
Water vapor
CH4
NH3
Mixture of gases
("primitive
atmosphere")
H2
Condenser
Water
• formed organic
compounds
– amino acids
– adenine
ANIMATION: THE MILLER-UREY EXPERIMENThttp://ecsd-fl.schoolloop.com/L.15.8
Heated water
("ocean")
Condensed
liquid with
complex,
organic
molecules
Stanley Miller
University of Chicago
produced
-amino acids
-hydrocarbons
-nitrogen bases
-other organics
It’s ALIVE!
http://highered.mheducation.com/sites/9834092339/student_view0/c
hapter26/animation_-_miller-urey_experiment.html
Origin of Cells (Protobionts)
• Bubbles  separate inside from outside
 metabolism & reproduction
* Coacervates
Bubbles…
Tiny bubbles…
Prokaryotes
• Prokaryotes dominated life
on Earth from 3.5–2.0 bya
3.5 billion year old
fossil of bacteria
modern bacteria
chains of one-celled
cyanobacteria
Stromatolites
Fossilized mats of
prokaryotes resemble
modern microbial
colonies
Lynn Margulis
Oxygen atmosphere
• Oxygen begins to accumulate 2.7 bya
– reducing  oxidizing atmosphere
• evidence in banded iron in rocks = rusting
• makes aerobic respiration possible
– photosynthetic bacteria (blue-green algae)
First Eukaryotes
~2 bya
• Development of internal membranes
– create internal micro-environments
– advantage: specialization = increase efficiency
• natural selection!
infolding of the
plasma membrane
plasma
membrane
endoplasmic
reticulum (ER)
nuclear envelope
nucleus
DNA
cell wall
Prokaryotic
cell
Prokaryotic
ancestor of
eukaryotic
cells
plasma
membrane
Eukaryotic
cell
Endosymbiosis
http://highered.mheducation.com/sites/9834092339/student_view0/chapt
er26/animation_-_endosymbiosis.html
• Evolution of eukaryotes
– origin of mitochondria
– engulfed aerobic bacteria, but
did not digest them
– mutually beneficial relationship
• natural selection!
internal membrane
system
aerobic bacterium
mitochondrion
Endosymbiosis
Ancestral
eukaryotic cell
Eukaryotic cell
with mitochondrion
Endosymbiosis – Lynn Margolis
http://www.classzone.com/cz/books/bio_12_fl/resources/htmls/an
imated_biology/unit4/bio_ch12_0373_ab_endosym.html
• Evolution of eukaryotes
Eukaryotic
cell with
mitochondrion
– origin of chloroplasts
– engulfed photosynthetic bacteria,
but did not digest them
– mutually beneficial relationship
• natural selection!
photosynthetic
bacterium
chloroplast
Endosymbiosis
Eukaryotic cell with
chloroplast & mitochondrion
mitochondrion
http://www.classzone.com/cz/books/bio_12_fl/resources/html
s/animated_biology/unit4/bio_ch12_0373_ab_endosym.html
Cambrian explosion
• Diversification of Animals
– within 10–20 million years most of the major phyla of
animals appear in fossil record
543 mya
Trilobite
Kingdom
Bacteria
Kingdom
Archaebacteria
Kingdom
Protista
Kingdom
Fungi
Kingdom
Plantae
Kingdom
Animalia
Questions
1. One of the accepted scientific theories describing
the origin of life on Earth is known as chemical
evolution. According to this theory, which of the
following events would need to occur first for life to
evolve?
a. onset of photosynthesis
b. origin of genetic material
c. synthesis of organic molecules
d. formation of the plasma membrane
2. Which types of organisms developed first due to
the early environmental conditions on Earth?
a. prokaryotic and aerobic
b. prokaryotic and anaerobic
c. eukaryotic and anaerobic
d. eukaryotic and anaerobic
3. The Miller-Urey experiment of 1953 was designed to test
the hypothesis that lightning supplied the energy needed to
turn atmospheric gases into organic molecules such as
amino acids. Which of the following describes why the
Miller-Urey theory is widely accepted today?
a. Amino acids spontaneously form from molecules in the
atmosphere today.
b. Organic molecules are present today in extremely high
concentrations.
c. The process of synthesizing organic molecules from a
mixture of gases has been successfully modeled in the
laboratory.
d. No other alternative hypotheses have been introduced.
4. The diagram below shows a proposed theory of the origin
of eukaryotic cells, called endosymbiosis.
Which of the following explains why cells that contained
mitochondria-like organelles had an evolutionary advantage?
a. They were able to photosynthesize
b. They had more DNA
c. They were able to make more use of available energy
d. They were immune to bacterial invasion
5. Which of the following gases is least likely to
have existed in the early atmosphere of the earth?
a. NH3
b. CO2
c. N2
d. O2
6. When Pasteur prepared his long curved neck flash
for his experiment, he was trying to disprove which
idea?
a. abiogenesis
b. theory of use and disuse
c. theory of natural selection
d. spontaneous generation
7. Miller and Urey's experiments proved thata. life evolved on earth from inanimate chemicals.
b. complex organic molecules can form spontaneously under
conditions that probably existed on the early earth.
c. RNA can act as an enzyme and assemble new RNA
molecules from RNA templates.
d. bacteria were the first type of living organism to appear on
the earth.
8. The endosymbiotic theory explains-
a. the origin of all organelles in eukaryotic cells
b. how bacterial cells can invade eukaryotic cells and
cause disease
c. how mitochondria and chloroplasts originated
from free-living cells
d. how eukaryotic cells consume food
9. Scientists have recently discovered hydrothermal vent communities on
the ocean floor. A diagram of a hydrothermal vent community is shown in
the figure below.
• The organisms in this community live near heated vents. Inorganic
compounds such as sulfides mix with extremely hot water when they
are released from the vents. Bacteria use the sulfides to make food for
themselves and other animals. Many of these bacteria live in the bodies
of the giant tubeworms and the giant white clams that live in this
community.
• The bacteria that live in the bodies of the giant tubeworms and the
giant white clams are classified as
• a. eukaryotes
• b. prokaryotes
• c. plants
• d. fungi
10. Miller and Urey subjected hydrogen gas, water vapor,
ammonia, and methane gases to sparks in a reacting
chamber. What was produced, giving support to the
primordial soup model of the origin of life?
a. primitive plants
b. organic compounds
c. single-celled organisms
d. membrane-bound organelles
11. According to the primordial soup model, the first organic
molecules could have formed from simpler inorganic
substances in Earth’s early oceans, but only if there were a
source of energy to cause such chemical reactions to take
place.
Which are possible sources of energy that could have led to
the production of these first precursors to life?
a. lightning and cellular respiration
b. nuclear radiation and photosynthesis
c. photosynthesis and cellular respiration
d. solar radiation, volcanic eruptions, and lightning
12. Which of the following best describes the current
scientific thinking about the origins of life on Earth?
• A. It has been proven that life came to Earth on
comets.
• B. Scientific explanations have changed based on
new information.
• C. Fossil evidence of the earliest form of life is
common and well accepted.
• D. The creation of organic molecules in ancient
“soup” is the only possible explanation for the
origin of life on Earth.
• 13. Which is NOT considered a possible
location on primitive Earth where conditions
would have allowed the synthesis of complex
organic compounds?
• A. Near volcanoes
• B. Dry, hot areas
• C. Deep ocean vents
• D. Shallow seashores
14. Which life forms would have been among
the first organisms on Earth?
• A. Angiosperms
• B. Archaea
• C. Gymnosperms
• D. Herbivores
15. What important role did blue-green bacteria
play in the history of life on Earth?
• A. They performed photosynthesis and filled
the atmosphere with water vapor.
• B. They provided the basis for a food web that
eventually supported plants.
• C. They performed photosynthesis and led to
an oxygenated atmosphere.
• D. They performed respiration and filled the
atmosphere with oxygen.
16. An energy input is necessary to build
complex organic molecules from simpler
molecules.
• What energy source possibly created the
building blocks of life during the early parts
of the creation of life on Earth?
•
A. Wind
•
B. Lightning
•
C. Tornadoes
•
D. Seismic waves
Intro to Macromolecules
Macromolecule
Where it is found What it does
Protein
Meat, Fish, Cheese
Enzymes, structural,
transportation,
hormones among many
other functions in living
organism.
Carbohydrate
Sugar, Breads, Fruits,
Pasta, Rice
Short term energy
Lipid
Fats
Long term energy
storage; an important
component of the cell
membrane.
Nucleic Acid
RNA and DNA
Carries genetic
information
Origin of Life Chemistry:
Intro to macromolecules
Revealing the Origins of Life
Escambia Biology
• http://ecsd-fl.schoolloop.com/L.15.8
http://www.youtube.com/watch?v=sjE-Pkjp3u4
GREAT REVIEW