Origin of Life
The oxygen revolution changed Earth's environment dramatically. which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?
the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules
The Miller-Urey experiment demonstrated
the kinds of molecules that could have been produced on the early earth
Miller and Urey's experiments proved that
complex organic molecules can form spontaneously under conditions that probably existed on the early earth
All of the following have been proposed as a type of protocell except
endosymbionts
Which of the following possible explanations of the origin of life on earth allows testable hypotheses to be constructed?
evolution
A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of
exaptation
Which of the following steps has not yet been accomplished by scientists studying the origin of life/
formation of protocols that use DNA to direct the polymerization of amino acids
Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.
genetic drift
Which of the following is not a characteristic of the first cells?
genome composed of RNA
The endosymbiotic theory explains
how mitochondria and chloroplasts originated from free-living cells
Life on earth is carbon based. Similar molecules could be formed with
silicon
The oldest fossils found so far date back to the
Archean Era
Multicellularity arose only once in earth's history but this line branched out 4 times.
False
Approximately what percentage of today's atmosphere is oxygen?
21%
How long have bacteria lived on the earth?
3.5 billion years
Evidence indicates that microfossils already existed at least:
3.5 billion years ago.
How old is the earth?
4.6 billion years old
How long did the earth exist before life appeared on it?
1 billion years
Microfossils of the earliest organisms indicate that they resemble the present day spirochetes.
False
Which factor most likely caused animals and plants in India to differ greatly from species in nearly southeast Asia?
India is in the process of separating from the rest of Asia
Which of the following gases is least likely to have existed in the early atmosphere of the earth?
Oxygen
Multicellular fossils appear at the beginning of the
Phanerozoic Era
Living organisms are classified into 6 different kingdoms. However, these kingdoms are not static and will change in the future.
True
A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of
a change in a developmental gene or in its regulation that altered the spatial organization of body parts.
Which of the following is not found in a lipid coacervate droplet or a proteinoid microsphere?
a nucleus
What molecule produced in experiments performed by others (using Miller-Urey's model) is key to explaining the evolution of the hereditary molecules (DNA and RNA)?
adenine
What did Miller and Urey use as a source of energy in their experiments?
an electrical spark
The early earth was a harsh environment and present day organisms that could possibly have survived that type of environment are
archeabacteria
Microfossils found in rocks that date to be about 1.5 billion years old
are larger organisms compared to earlier microfossils
The earliest cellular life forms appear to have been
bacteria
Which of the following organisms alive today is likely to be most similar to the first life forms that evolved on the earth?
methane-producing bacteria
Which of the following is not a characteristic of all living organisms?
movement from place to place
Which of the following traits evolved last (i.e., most recently)?
multicellularity
According to the scientific theory of the origin of life on earth, life arose spontaneously from inanimate chemicals. Do scientists think this process is still going on on our planet today?
no, because conditions on earth have changed and are no longer conducive to spontaneous evolution of life
Scientists generally agree that the first molecules formed as life evolved were
none of the above
Within our own solar system, the most likely candidate for having life on it is
our moon
What gas in today's atmosphere shields us from ultraviolet radiation?
ozone
Which of the following was not a source of energy on the early earth?
ozone
Of the following, ____ was not contained in the Miller-Urey original mixture.
phosphorus
The oxygen that is present in our atmosphere comes primarily from the
photosynthesis of plants, algae, and bacteria
Fossilized stromatolites
resemble structures formed by bacterial communities that are found today in some warm, swallow, salty bays
The site of life's origin is
unknown
The Miller-Urey experiments yielded
urea, hydrogen cyanide, and amino acids