Unit Five: Biological Diversity
Chapter 26 - Origin of Life
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or
answers the question.
1) What is the strongest evidence that protobionts may have formed spontaneously?
A) The fossil record found in the stromatolites.
B) The discovery of ribozymes, showing that prebiotic RNA molecules may have been
autocatalytic.
C) The production of organic compounds within a laboratory apparatus simulating
conditions on early Earth.
D) The abiotic synthesis of polymers.
E) The relative ease with which liposomes can be synthesized in laboratories.
2) Current theories of prebiotic evolution are based on evidence for all of the following
except the abiotic
A) production of small organic molecules.
B) production of liposomes.
C) replication of oligopeptides.
D) origin of DNA-protein interactions.
E) polymerization of amino acids.
3) The first genetic material was most likely a(n)
A) DNA polymer.
B) protein enzyme.
C) DNA oligonucleotide.
D) RNA polymer.
E) protein.
Use the following information to answer the questions below.
According to the Miller-Urey experimental results, chemical evolution leading up to and
including the formation of living matter is believed to have occurred during the early
history of Earth. Below are four pairs of events that might have occurred during this
period. Judge the relative time of each of these pairs of events according to the key
below.
A. Event I occurred before Event II.
B. Event II occurred before Event I.
C. Events I and II occurred simultaneously.
4) Event I: nitrogen oxides and carbon dioxide in the atmosphere
Event II: free oxygen in the atmosphere
5) Event I: formation of photosynthetic organisms
Event II: formation of heterotrophic organisms
6) Event I: formation of amino acids
Event II: formation of enzymes
7) Event I: atmosphere of water, methane, and ammonia
Event II: reducing atmosphere
8) Approximately how far does the fossil record extend back in time?
A) 6,000 years
B) 3,500,000 years
C) 6,000,000 years
D) 3,500,000,000 years
E) 5,000,000,000,000 years
9) Which of the following is the strongest evidence that prokaryotes evolved before
eukaryotes?
A) the primitive structure of plants
B) meteorites that have struck the Earth
C) abiotic experiments that constructed liposomes in the laboratory
D) Liposomes look like prokaryotic cells.
E) The oldest fossilized cells resemble prokaryotes.
10) In his laboratory simulation of the early Earth, Miller observed the abiotic synthesis
of
A) liposomes.
B) complex organic polymers.
C) amino acids.
D) nucleoli.
E) DNA.
11) Which of the following factors was most important in the origin of life on Earth?
A) competition for oxygen
B) biotic synthesis of organic molecules
C) low levels of solar energy
D) natural selection acting on molecules and protobionts
E) low-intensity electrical discharges in the upper atmosphere
12) Which of the following has not yet been synthesized in laboratory experiments
studying the origin of life?
A) oligopeptides and other oligomers
B) protobionts that use DNA to program protein synthesis
C) liposomes with selectively permeable membranes
D) amino acids
E) lipids
13) What condition would have made the primitive atmosphere of Earth more conducive to
the origin of life than the modern atmosphere of Earth? The primitive atmosphere
A) had more oxygen than the modern atmosphere, and thus it successfully sustained the
first living organisms.
B) had a layer of ozone that shielded the first fragile cells.
C) may have been a reducing one that facilitated the formation of complex substances
from simple molecules.
D) had less free energy than the modern atmosphere, and thus newly formed organisms
were less likely to be destroyed.
E) removed electrons that impeded the formation of protobionts.
14) A key role that clay may have played in the origin of life is the tendency for clay to
A) provide a catalytic surface for the polymerization of organic monomers.
B) generate life through spontaneous processes.
C) assemble into liposome membranes.
D) plug gaps in membranous bilayers so that electrical differences could be maintained
across them.
E) remain suspended in solution.
15) In what way were conditions on early Earth different from those on modern Earth?
A) The early Earth was intensely bombarded by large space debris.
B) The early atmosphere had significant quantities of ozone.
C) Less ultraviolet radiation penetrated the early atmosphere.
D) The early Earth had no water.
E) The early Earth had an oxidizing atmosphere.
Chapter 26 - Origin of Life
1) E
11) D
2) D
12) B
3) D
13) C
4) A
14) A
5) B
15) A
6) A
7) C
8) D
9) E
10) C