|
G & O |
ch. |
1, 9-15 |
|
Z & H |
ch. |
17, 18 |
(recommended by Prof. Zuckerman)
|
G & O |
ch. 10 |
1, 2, 4, 5 |
|
|
ch. 12 |
1, 2, 6 |
|
|
ch. 13 |
1, 2, 3, 5, 6, 8 |
|
|
ch. 14 |
2, 3, 10 |
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ch. 15 |
1, 2, 3, 4, 6 |
Origin of life:
-optical activity and molecules from living beings
-milestones of biological evolution
-characteristics of prokaryotic and eukaryotic cells
-conditions leading to eukaryotic life
Biological Evolution
-advantages of sexual reproduction
-advantages of diversity of species
-evolution of intelligence
-body mass vs. brain mass
-ways to distinguish evolutionary closeness
-cytochrome c, hemoglobin, genetic sequencing
Extinction Events:
-5 events that can lead to extinction
-impact,
-evidence for impacts in earth's past
-killing mechanism
-climate change
-factors affecting climate change
-ice ages
-snowball earth
-effects of plate tectonics
-supernovae
-humans
-continental drift
Properties of Present Terrestrial Biosphere:
-the greenhouse effect
-mechanism of the greenhouse effect
-common greenhouse gases
-uncertainties in the model
-factors affecting terrestrial surface temperature
-solar luminosity, earth's albedo, greenhouse effect
Convergent Evolution
-limits to size of organisms
-competition between gravity and pressure
-strength of material
-surface area to volume ratio
-large size? intelligence? flight?
-animal magnetism for locomotion
Life at the Extremes:
-extremes of: temperature, light level, dryness, radiation, pressure
-thermophiles
-properties and living conditions of thermophiles
-examples of thermophiles
-methanogens, tardigrades, cryptoendolithic lichen
-organisms found near the Mariana's trench
-freezing organisms: living vs. surviving
Future Terrestrial Biosphere:
-humans are changing evolution
-cosmic --> chemical --> biological --> social
-artificial intelligence
-genetic engineering
-cloning
Life in the Solar System:
-Surface Properties and Conditions of
-Venus
-runaway greenhouse effect
-Mars
-evidence for past life
-evidence for past water
-Viking tests for life
-Jupiter
-gas convection
-Moons of Gas Giants (Titan, Europa)
-Titan: thick atmosphere
-Europa: possibility of water ocean under ice
-Meteorite
-two types: stony, iron
-evidence of fossil life in Martian meteorite ALH84001
-evidence that it is from Mars
-organic molecules present in meteorites
Key Terms
Optical Activity: polarization response of molecules from living organism to incident radiation
Levrorotatry: molecules with left handed helicity
Dextrorotary: molecules with right handed helicity
Prokaryotic: primordial cells with no nucleus
Eukaryotic: cells with a nucleus
Bolide: impacting bodies (asteroids or comets)
Albedo: reflectivity of a surface
Positive Feedback: mechanisms that perturbs the system away from equilibrium
Snowball Earth: an earth covered with glaciers
Convergent Evolution: evolution towards similar traits in different animals
Extremozymes: organisms that live in extreme conditions
Thermophiles: organisms that live in high temperature regions (greater than ~60 degrees C)
Methanogens: organisms that respirate using H
Cryptoendolithic: hidden in rocks (refers to a type of lichen)
Tardigrades: organisms that can be desiccated and will live again when reconstituted
Cloning: producing an organism with identical DNA
Comparative Genomics: the science of comparing the DNA of different species
PAH (Polycyclic Aromatic Hydrocarbons): organic molecules that are benzene-like
Apollo Asteroids: earth-orbit crossing asteroids
Review Questions
(Remember, the answers indicated are bare bones. Yours should be much more involved.)
How does the layered structure of mica help originate life?
-more surface area for reactions
What is optical activity? What can it tell us about how many times life originated on Earth?
-see definition above. It indicates one origin of life, since there is equal probability of left and right helicity.
What are the advantages of sexual reproduction?
-mixing genes without mutations, good traits live while bad ones die
Why do some people think that Eukaryotes formed from clusters of prokaryotes?
-larger, came later, and organelles looks like prokaryotes.
What is symbiosis? Why is it desirable? Give an example of such a system.
-organisms that help each other live. Each organism can be simpler. Lichen
Why may diversity be undesirable?
-in a very homogeneous environment
Name 5 extinction mechanisms and name whether it is fast or slow.
-see above
What are some evidences that support an impact being responsible for the K-T extinction event?
-high iridium spike, shocked quartz, a crater with similar age
What causes ice ages?
-change in albedo of earth, tilt, precession, atmospheric content
How does the greenhouse effect work? What are the uncertainties in the models?
-greenhouse particles trap IR radiation but lets optical light thru. Cloud cover, albedo effects, sulphate particles
Why are there no giant insects?
-they're limited by surface area to volume ratio because they have no circulatory systems
Is intelligence the endpoint of evolution?
-can be argued both ways as covered in review session
How do magnetic bacterial navigate?
-flagella is attached at the appropriate end so that the alignment with Earth's magnetic field causes them to swim "down"
How does genetic engineering change evolution?
-it removes survival of the fittest, and replaces it with survival of humanly determined desirable traits
Why is it difficult to clone organisms from adult cells?
-the cells have differentiated and expressed particular genes
Why is Venus so different from Earth when its size is comparable?
-mainly because of its distance to the sun, it couldn't condense water
What kind of life do we think may exist on Mars? Why?
-fossil life, because conditions there now are very hostile.
How do we know that ALH84001 came from Mars?
-crystallization age, O isotope ratio, gas trapped in pockets
If life originated via panspermia, which planet may have contaminated which? Why?
-Mars contaminate Earth. Large bolides escape Mars easier.
What are the results of the Viking experiments on Mars to measure life?
-positive, but inconclusive because all processes can be from non-living sources
Why is complex life not probable on Jupiter?
-convection brings material down to a hot zone
What are the evidence supporting a liquid ocean under the icy crust on Europa?
-low surface relief, constant motion indicated by e.g. rills, magnetic field