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39 Cards in this Set

  • Front
  • Back
all organisms possess a genetic system based on replication of DNA
heredity
supernatural or divine origin
special creation
hypothesis that proposes meteors or cosmic dust brought life to earth
panspermia (extraterrestrial origin
life originated from inanimate materials
spontaneous origin
life most likely emerged under ___ conditions
high temperature
the early atmosphere
reducing atmosphere
in a reducing atmosphere, the exact conditions are ___.
there was an ample availabilty of ___ but very little ___.
unknown, hydrogen atoms, oxygen
ideas of origin
-the ocean's edge
-under frozen oceans
-deep in the earth's crust
-within clay
-deep-sea vents
origin-bubble hypothesis
ocean's edge
origin-problematic due to necessary conditions (temperature)
under frozen oceans
origin-byproduct of volcanic activity
deep in earth's crust
origin-was positively charged so it provided catalytic surface
within clay
origin-conditions suitable for Archaea
deep-sea vents
attempted to reproduce early reducing atmosphere and produce organic compounds from inorganic materials
Miller Urey Experiment
steps of Miller-Urey experiment
1. assembled reducing atmosphere rich in H and excluding gaseous oxygen
2. placed atmosphere over liquid water
3. maintained mixture at a temp lower than 100C
4. simulated lightning by bombarding it with energy in the form of sparks
3 hypotheses of chemical evolution
RNA, Protein, Peptide-Nucleic Acid worlds
c. evolution - molecules could not have consistently formed without a mechanism of heredity (replication)
RNA world
c. evolution - replication would be impossible without enzymes
Protein world
c. evolution - RNA is too unstable, thus a precursor must have existed
Peptide-nucleic acid world
certain molecules sontaneously formed bubbles (esp. protein and lipids) that shielded the hydrophobic regions of the molecules from contact with water
bubble theories
chemical concentrating, bubblelike structures
protobiont
protobionts allowed chemical complexity
primary abiogenesis
there is no major agreement on one ___ theory
bubble
resemble prokaryotes-lack a nucleus of more complex eukaryotes
microfossils
microfossils have been found in rocks as old as ___ yrs
2.5 billion
most primitive organisms-extreme condition prokaryotes
archaebacteria
archabacteria lack ___ in cell walls (a protein carbohydrate complex)
peptidoglycan
archaebacteria that produce methane
methanogens
some archaebacteria were ___(salt lovers) or ___(heat lovers)
halophiles, thermophiles
archaebacteria are thought to have split from ___ 2 billion years ago
bacteria
second major group of prokaryotes (contains most modern proks)
bacteria
bacteria has strong ___ and a simpler ___
cell walls, gene structure
photosynthetic blue-green algae
cyanobacteria
Eukaryotes arose about ___ years ago
1.5 billion
internal membrane-bound structures such as mitochondria and chloroplasts are thought to have evolved via ___
endosymbiosis
endosymbiosis
enrgy-producing bacteria were engulfed by larger bacteria which formed a beneficial symbiotic relationship
eukaryotic cells can ___ which carries out genetic recombination, the key to evolution
reproduce sexually
the development of ___ has arisen many times among eukaryotes and fosters specialization
multicellularity
some cells devote all energies to one task, other cells to another
specialization