the fossilized
remains of simple plants that are over 5 billion years old
3.5-billion-year-old
rocks with isotopes of carbon that seem to represent the metabolic
activity of organisms
the mineralized
remains of tiny animals
the fossilized
remains of cellular colonies dating from about 3 million years ago
none of the
above is true
2.
Abiotic synthesis of life is unlikely to occur today because _____.
insufficient
organic molecules are present in the oceans
free oxygen in
the atmosphere breaks down molecules as they form
there is
insufficient energy available to stimulate the formation of life
A and B are true
A, B, and C are
true
3.
The early atmosphere on Earth is thought to have LACKED which one of
the following gases?
methane
carbon dioxide
oxygen
water
nitrogen
4.
Oxygen gas probably first appeared on this planet in fairly large
quantities _____.
when it was
released due to electrical discharges in the early atmosphere
after
"green plant type" photosynthetic reactions evolved
about the time
the first living "cell" arose in the ancient seas
when the first
land animals arose
none of the
above
5.
Today, new life forms do not arise spontaneously from abiotic
materials. But spontaneous generation did occur some 3.5 to 4.0 billion
years ago. What accounts for this difference?
Organic
molecules can be produced from abiotic materials in laboratory
simulations.
All life forms
on our planet are believed to have a single origin.
The modern
atmosphere does not contain enough nitrogen gas.
The atmosphere
in which the earliest life forms arose came from volcanic degassing and
was rich in sulfur dioxide.
Early Earth's
atmosphere contained little or no free oxygen.
6.
Which of the following is thought to have been the first step in the
origin of life?
cooperation
among molecules
formation of
polypeptide spheres
formation of
organic monomers
replication of
primitive genes
formation of
organic polymers
7.
In their experiment on the abiotic synthesis of organic compounds,
which of the following gases did Miller and Urey use to simulate Earth's
early atmosphere?
H2O
only
H2O
and CH4 only
H2O,
CH4, and H2 only
H2O,
CH4, H2, and NH3
H2O,
CH4, H2, and NH3 and O2
8.
The Miller abiotic synthesis experiment (and subsequent, similar
experiments) showed that _____.
life can be
created in a test tube
long chains of
DNA can form under abiotic conditions
simple organic
molecules can form spontaneously under conditions like those thought to
prevail early in Earth's history
the earliest
life forms introduced large amounts of oxygen into the atmosphere
the
"concentration gap" probably prevented simple organic
molecules from polymerizing
9.
The presence of which one of the following was absolutely essential
for the development of the first life forms?
heat produced
by a planet whose surface was still warm
volcanoes
spewing forth various gases
electrical
discharges from lightning
a reducing
atmosphere
UV light
10.
Cech has suggested that the first self-replicating molecules were
_____.
DNA
phospholipids
viruses
true proteins
RNA
11.
Biologists are interested in the role of liposomes in the origin of
life. They think that liposomes might show how _____.
raw materials
for organic compounds formed
the formation
of organic polymers, such as carbohydrates and RNA, were catalyzed
primitive cell
membranes could form, grow, and divide
energy was
supplied for the metabolism of the first simple cells
all of the
above
12.
Protobionts of one sort or another—aggregates of abiotically
produced molecules—display all but one of the following properties of
living cells. The one property they LACK is a(n) ____________.
ability to
absorb substances from their surroundings
genetic library
selectively
permeable membrane
transmembrane
voltage potential
ability to grow
13.
How might deep-sea vents have been important in the origin of life?
They may have
been the source of some of the organic compounds that cells use in
energy metabolism.
Sulfides of
iron and nickel common in deep-sea vents are excellent catalysts.
The high
temperatures associated with deep-sea vents were a source of energy for
the reactions necessary for the formation of protobionts.
Oxygen was
abundant near deep-sea vents and encouraged the formation of polymers.
They may have
been the source of some of the organic compounds that cells use in
energy metabolism; sulfides of iron and nickel common in deep-sea vents
are excellent catalysts; and the high temperatures associated with
deep-sea vents were a source of energy for the reactions necessary for
the formation of protobionts.
14.
Polymerization __________.
is the
generation of large molecules by small molecules