Bio 1215-Chapter 1
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Bio 1215-Chapter 1
earth living things
earth, living things
what is the best evidence about how our universe began?
began with a
"big bang" 13.7 billion
How old is the earth and the solar system?
How did the earth and solar system form?
from the coming together of
joined by gravity
How did the elements settle in the earth?
in early earth
How old are the oldest rocks and how were they discovered?
oldest rocks over
years old and discovered by
when did surface water stabilize into oceans?
what were the 5 major elements found in the surface and atmosphere?
Very little O2
when did the origin of life begin?
more than 3 billion years ago
O2 is destructive to bonds in ____________ .
what are some things that define a living thing? List at least 7.
ability to grow
respond to stimuli
How old are the oldest fossils?
what are some evidence that life may have began earlier, before atmosphere stabilized? (2)
why did the first organisms use a process other than cellular respiration to transform energy? what was the alternative?
because there was
very little oxygen
in the atmosphere
how does methane and the green house effect relate?
may have warmed the climate
via the green house effect
when did photosynthesis evolve?
more than 2.5 billion
which organism might have been the first to use photosynthesis?
what are stromatolites?
what did photosynthetic bacteria add to the atmosphere and water bodies? what is the proof?
is evidence b/c oxygen was not present therefore no rust formed on metals
how did rising oxygen levels affect early life? why?
many kinds of early life because oxygen
when did eukaryotes first appear?
when did the first animals appear?
A great diversification of animals occurred in which period?
the Cambrian explosion
(all these animal groups were aquatic)
when did the first plants and fungi appear?
about 500 million
how old are humans?
about 200 000
what are 2 ways the earth is still changing?
climate is changing
what does the chemical origin of life suggest?
theory suggest that life began
why is it unlikely that new forms of life are forming from simple chemicals today? (2)
lots of reactive oxygen around
(prevents molecules from combining into organic molecules)
existing organisms would consume organic molecules
before they could assemble into something more complicated
what are the 4 potential steps in the chemical origin of life?
abiotic synthesis of organic monomers
monomers being converted it polymers
origin of self-replicating molecules
(allowing for inheritance)
packaging into membrane-enclosed bags
what did Miller and Urey try to do?
recreate the conditions of the early earth
to test how monomers might have formed on the young earth
what did Miller and Urey find after their experiment?
found several amino acids had formed
Monomers forming into polymers is called?
how can dehydration synthesis occur in the early earth?
can occur if
dilute monomer solutions drip onto hot rocks or sand
what natural elements can increase reaction rates? (2)
: have polar and charged areas
: like iron in pyrite act as catalysts
what unnatural elements speed up reactions? (3)
what are 5 reasons of why RNA may have come before DNA?
short pieces can be made abiotically
binds to amino acids,
helping them to join
DNA is more stable
and must have come after
what are protobionts?
"pre-cells" (membrane bags)
how can protobionts be made abiotically?
phospholipids in water
what evidence could suggest that organic molecules got here from space?
strings of sugars
have been found
what evidence could suggest that organic molecules began in the ice?
nucleic acids can be form
ed in ice in the lab
As water freezes, other molecules are concentrated into tiny __________________ within it.
liquid water bubbles
what element can be formed in the ice when in a lab?
bits of nucleic acids