Deck 25: The Origin and Diversity of Life

Question 1

The early Earth's reducing atmosphere probably contained all of the following except

A)carbon dioxide.
B)water.
C)oxygen.
D)hydrogen sulfide.
E)methane.

Answer 1

C

Question 2

Two principal organelles in eukaryotes that were apparently derived from different types of bacteria are the

A)microfilaments and microtubules.
B)mitochondria and chloroplasts.
C)rough ER and smooth ER.
D)plasma membrane and nuclear membrane.

Answer 2

B

Question 3

An experimental test of the hypothesis to explain the origin of the first organic compounds on Earth might include all of the following sequential steps except

A)assembling an atmosphere with H₂,CH₄,NH₃,and H₂S.
B)placing this atmosphere over liquid water.
C)inoculating with a few bacteria to get the process started.
D)increasing the temperature of the gases.
E)providing energy with electrical spark discharges.

Answer 3

C

Question 4

Eukaryotic cells acquired mitochondria and chloroplasts by

A)endosymbiosis.
B)exocytosis.
C)pinocytosis.
D)mutation.
E)natural selection.

Question 5

Which of the following was produced in experiments on primitive Earth conditions conducted by Miller-Urey and others?

A)ammonia and water
B)amino acids
C)CO₂ and H₂O
D)ammonia and hydrogen sulfide
E)methane and oxygen

Question 6

A scientist is studying endosymbiosis in cells.This means she is investigating

A)how mitochondria and chloroplasts were derived from eukaryotic cells.
B)how mitochondria and chloroplasts were derived from prokaryotic cells.
C)how mitochondria and chloroplasts evolved into eukaryotic cells.
D)how mitochondria and chloroplasts evolved into prokaryotic cells.

Question 7

The oldest fossils of eukaryotes have been estimated to be

A)6000 years old.
B)8 billion years old.
C)4)5 billion years old.
D)1)5 billion years old.
E)1995 years old.

Question 8

Life apparently originated on Earth about

A)1 million years ago.
B)6000 years ago.
C)4)5 billion years ago.
D)8 billion years ago.
E)3)5 billion years ago.

Question 9

Which one of the following statements about endosymbiosis and the origin of the eukaryotic cell is FALSE?

A)Mitochondria are the descendants of purple bacteria.
B)The chloroplasts of red and green algae are the descendants of cyanobacteria.
C)Algae incorporated prokaryotic cells that became chloroplasts,but never acquired mitochondria.
D)Many compartments of the eukaryotic cell are derived from the endomembrane system.
E)Ultimately,both the chloroplast and the mitochondria of eukaryotes are descendants of prokaryotic cells.

Question 10

Which of the following was demonstrated by the Miller-Urey experiment?

A)Life began in the oceans.
B)Life can be started experimentally in the laboratory.
C)Organic molecules important to life could have been formed from a vast array of simple chemicals.
D)Life began on the prebiotic Earth 3.5 billion years ago.

Question 11

Homo sapiens have existed on earth for 2% of the earth's history.

Question 12

Imagine that NASA discovered a new planet with an atmosphere rich in hydrogen gas,hydrogen sulfide,ammonia and methane.We would call this a(n)

A)reducing atmosphere,because of the availability of hydrogen atoms that can donate electrons.
B)reducing atmosphere because the atmosphere would reduce the energy necessary to build molecules.
C)oxidizing atmosphere because of the availability of oxygen compounds.
D)oxidizing atmosphere because of the lack of oxygen gas.

Question 13

The apparatus in the figure was used by Stanley Miller and Harold Urey to study the origin of life on Earth.What compound was excluded from the apparatus so that it would form a reducing atmosphere?

A)CO₂
B)O₂
C)NH₃
D)H₂
E)H₂O

Question 14

The group that probably gave rise to chloroplasts is the

A)cyanobacteria.
B)green photosynthetic bacteria.
C)purple sulfur bacteria.
D)nonsulfur purple bacteria.
E)methane bacteria.

Question 15

All of the following were produced in experiments on primitive Earth conditions conducted by Miller-Urey and others,except for

A)amino acids.
B)organic molecules.
C)prokaryotes.
D)hydrogen cyanide.
E)urea.

Question 16

The oldest microfossils are of

A)prokaryotes.
B)eukaryotes.
C)insects.
D)pollen grains.
E)small animals.

Question 17

The age of the Earth according to modern estimations is about

A)8 billion years.
B)4)6 billion years.
C)3)5 billion years.
D)1)5 billion years.
E)a few thousand years.

Question 18

In the original experiments by Stanley Miller and Harold Urey to synthesize organic molecules in an abiotic environment,which one of the following would you NOT expect to find in the collection flask?

A)urea
B)amino acids
C)ATP
D)adenine
E)formaldehyde

Question 19

It has been discovered that enzyme-like catalysis can be carried out not only by enzymes but also by

A)sugars.
B)DNA.
C)phospholipids.
D)RNA.
E)steroids.

Question 20

True multicellularity is a major characteristic of

A)all eukaryotes and a few prokaryotes.
B)animals and plants only.
C)eukaryotes only.
D)protists,plants,and animals.
E)prokaryotes and protists.

Question 21

Why is a reducing atmosphere conducive to the origin of life?

A)It is more favorable for the development of organic molecules.
B)It is rich in free oxygen.
C)It is devoid of organic molecules.
D)It is very similar to today's atmosphere.

Question 22

Vascular plants appeared about 450 million year ago.Vascular plants have existed on earth for ________.

A)10% of its history
B)20% of its history
C)50% of its history
D)75% of its history
E)90% of its history

Question 23

RNA was probably the first molecule used to encode genetic information; the use of DNA came later.This is due to RNA's inherent stability and its ability to store information more accurately than DNA.

Question 24

If a scientist found very high concentrations of organic biomarkers deep inside a 3.9 billion year old meteorite,how would this effect the explanation of the origins of life on Earth?

A)This would prove the extraterrestrial origin of life.
B)This would provide evidence for the extraterrestrial origin of life.
C)This would disprove the terrestrial origin of life.
D)This would provide evidence for the uniqueness of life on earth.

Question 25

What is the advantage of having cyanobacteria living inside a cell?

A)Enhanced protection of DNA
B)Intracellular production of glucose
C)Much more efficient protein synthesis
D)Allows the cell to manufacture ATP

Question 26

Infolding of the cellular membrane has led to the development of the

A)chloroplast
B)mitochondria
C)nuclear envelope
D)nucleolus
E)ribosome

Question 27

A scientist is analyzing air bubbles trapped in ancient rocks that can be used to understand the ancient atmosphere.What do you expect the scientist will observe when comparing rocks younger than 3.8 billion years old to rocks older than 3.8 billion years?

A)The ratio of the carbon-12 isotope will be lower in the younger rocks,because living organisms preferentially use carbon-12 over other isotopes.
B)The younger rocks will have higher levels of carbon dioxide,because there was no carbon dioxide in the atmosphere before animals evolved and expelled it as waste.
C)The ratio of carbon-12 will be lower in the older rocks,because carbon-12 had to build up on earth before life could evolve.
D)The amount of carbon will vary unpredictably in the younger rocks,because rock weathering added carbon dioxide to the atmosphere,and volcanic activity sequestered it.

Question 28

Which eon would contain rocks with no fossils?

A)Archean
B)Hadean
C)Proterozoic
D)Phanerozoic

Question 29

During the Snowball Earth temperatures at the equator rarely exceeded -20 degrees Celsius.Why didn't heat from the sun melt the ice?

A)The high levels of atmospheric moisture created extensive cloud cover.
B)Ice reflected most of radiant energy.
C)The ozone layer absorbed all the heat.
D)The earth's core was cooled and kept the ice frozen.

Question 30

How would the hydrolysis of phosphodiester bonds impede the origin of life?

A)It would slow the rate of protein synthesis.
B)It would prevent the assembly of nucleic acids.
C)It would stop the formation of cell membranes.
D)It would digest amino acids.

Question 31

What would result for global climate from a massive drop in atmospheric carbon dioxide?

A)An increase in ocean temperature
B)Increased rock weathering
C)A decrease in surface temperature
D)Increased nitrogen availability
E)A decrease in free oxygen content

Question 32

Why have plants been implicated in the Ordovician and Devonian glaciations,but not the Proterozoic glaciations?

A)Proterozoic plants used anoxygenic photosynthesis.
B)Proterozoic plants had simple root structures that did not increase rock weathering.
C)Land plants had not yet evolved during the Proterozoic.
D)The nonvascular plants present during the Proterozoic did not contribute to global nutrient cycles.

Question 33

How did humans colonize the New World?

A)Early humans walked across a land bridge during periods of lowered sea level.
B)Christopher Columbus and a host of other explorers were the first to colonize the Americas.
C)Humans drifted across the Atlantic on primitive canoes.
D)Humans were present during the break-up of Gondwana.

Question 34

Prokaryotic organisms were the only life-forms present on earth for almost 2 billion years.Multicellular eukaryotes have only been around for about 25% of earth's history

Question 35

Why is there free oxygen in the air?

A)Organisms need oxygen to manufacture ATP.
B)Free oxygen has been present since the formation of the earth's atmosphere.
C)Evaporation of the oceans liberated oxygen.
D)It is a by-product of photosynthesis.
E)Free oxygen has seeped from cracks in the earth's crust.