Question 1

Ribozymes may have originally developed by ____.

Accepted Answer

A)  ATP synthesis 
B)  the chance assembly of RNA molecules 
C)  cellular respiration 
D)  glycolysis 
E)  electron transfer systems 
A)  ATP synthesis 
B)  the chance assembly of RNA molecules 
C)  cellular respiration 
D)  glycolysis 
E)  electron transfer systems

Question 2

Fatty acids and ribozymes are incompatible as early molecules of life because ____.

Accepted Answer

A)  they have different pH requirements 
B)  they most likely developed millions of years apart 
C)  fatty acid vesicles are impermeable to ribozymes bound to ferrous oxide 
D)  magnesium is required for ribozyme function but causes fatty acids to precipitate 
E)  magnesium is required for fatty acids to form vesicles but causes ribozymes to precipitate 
A)  they have different pH requirements 
B)  they most likely developed millions of years apart 
C)  fatty acid vesicles are impermeable to ribozymes bound to ferrous oxide 
D)  magnesium is required for ribozyme function but causes fatty acids to precipitate 
E)  magnesium is required for fatty acids to form vesicles but causes ribozymes to precipitate

Question 3

Most scientists believe that prokaryotes evolved from eukaryotes .

Accepted Answer

A) True 
 B)False

Question 4

The ancestor of the three domains of life was ____.

Accepted Answer

A)  a prokaryotic bacterium 
B)  an archaean endosymbiont 
C)  a proto-eukaryote 
D)  the last universal common ancestor (LUC
A)  
E)  none of these are correct 
A)  a prokaryotic bacterium 
B)  an archaean endosymbiont 
C)  a proto-eukaryote 
D)  the last universal common ancestor (LUC
A)  
E)  none of these are correct

Question 5

Why is the absence of atmospheric oxygen (O2) so important to the Oparin-Haldane hypothesis?

Accepted Answer

A)  Oxygen is corrosive and thus would have degraded many of the metallic compounds on Earth's surface, releasing toxic gasses into the new atmosphere. 
B)  Oxygen is more reduced than hydrogen gas, methane, or ammonia. 
C)  Oxygen would have supported microorganisms that promote chemical decay. 
D)  Oxygen is able to reverse reactions by removing electrons and hydrogen from organic molecules, thus destroying the first organic compounds as quickly as they developed. 
E)  Oxygen would have caused multiple explosions, converting chemical energy into heat energy and rendering that energy unavailable for driving the synthesis of organic molecules. 
A)  Oxygen is corrosive and thus would have degraded many of the metallic compounds on Earth's surface, releasing toxic gasses into the new atmosphere. 
B)  Oxygen is more reduced than hydrogen gas, methane, or ammonia. 
C)  Oxygen would have supported microorganisms that promote chemical decay. 
D)  Oxygen is able to reverse reactions by removing electrons and hydrogen from organic molecules, thus destroying the first organic compounds as quickly as they developed. 
E)  Oxygen would have caused multiple explosions, converting chemical energy into heat energy and rendering that energy unavailable for driving the synthesis of organic molecules.

Question 6

Protocells likely grew within microscopic compartments in porous alkaline vent chimneys, where ____.

Accepted Answer

A)  protocells could use the energy provided by H+gradients 
B)  the vents offered physical protection 
C)  protocells could use readily available ammonia sources 
D)  the vents funneled geothermal warmth 
E)  the vents were the right size 
A)  protocells could use the energy provided by H+gradients 
B)  the vents offered physical protection 
C)  protocells could use readily available ammonia sources 
D)  the vents funneled geothermal warmth 
E)  the vents were the right size

Question 7

The ____ provides evidence that RNA molecules generated the first proteins.

Accepted Answer

A)  redundancy of the genetic code 
B)  ability of rRNA to catalyze the formation of peptide bonds between amino acids 
C)  polymerase activity of some ribozymes 
D)  cleavage of mRNA molecules by rRNA 
E)  physical structure of polypeptides 
A)  redundancy of the genetic code 
B)  ability of rRNA to catalyze the formation of peptide bonds between amino acids 
C)  polymerase activity of some ribozymes 
D)  cleavage of mRNA molecules by rRNA 
E)  physical structure of polypeptides

Question 8

E ukaryotic evolution relied on ____.

Accepted Answer

A)  horizontal gene transfer from bacteria 
B)  endosymbiosis of prokaryotic cells 
C)  an archaean ancestor 
D)  natural selection 
E)  all of these are correct 
A)  horizontal gene transfer from bacteria 
B)  endosymbiosis of prokaryotic cells 
C)  an archaean ancestor 
D)  natural selection 
E)  all of these are correct

Question 9

What key assumption of the endosymbiotic theory is observed in living animals?

Accepted Answer

Engulfed cells and organelles are observ

Question 10

The earliest evidence of biochemical reactions by living cells dates to about ____ billion years ago.

Accepted Answer

A)  0.5 
B)  1 
C)  1.5 
D)  2 
E)  3.7 
A)  0.5 
B)  1 
C)  1.5 
D)  2 
E)  3.7

Question 11

Stromatolites are fossils of ancient, photosynthetic cyanobacteria .

Accepted Answer

A) True 
 B)False

Question 12

The first truly living cells must have been prokaryotic in structure .

Accepted Answer

A) True 
 B)False

Question 13

The Sun provided ____ in order to power the development of life on early Earth.

Accepted Answer

A)  continual energy 
B)  a temperature range for liquid water to form 
C)  radiation to power mutations 
D)  continual energy and a temperature range for liquid water to form 
E)  continual energy, a temperature range for liquid water to form, and radiation to power mutations 
A)  continual energy 
B)  a temperature range for liquid water to form 
C)  radiation to power mutations 
D)  continual energy and a temperature range for liquid water to form 
E)  continual energy, a temperature range for liquid water to form, and radiation to power mutations

Question 14

Molecules that are able to store and reproduce genetic information are known generally as ____.

Accepted Answer

A)  molecular hard drives 
B)  molecular replicators 
C)  DNA 
D)  RNA 
E)  ribozymes 
A)  molecular hard drives 
B)  molecular replicators 
C)  DNA 
D)  RNA 
E)  ribozymes

Question 15

One criticism of the Miller-Urey experiment among scientists is it ____.

Accepted Answer

A)  was based on an oxidizing environment 
B)  was likely contaminated with modern atmosphere 
C)  added too much energy 
D)  was based on a reducing environment 
E)  did not add the proper starting components 
A)  was based on an oxidizing environment 
B)  was likely contaminated with modern atmosphere 
C)  added too much energy 
D)  was based on a reducing environment 
E)  did not add the proper starting components

Question 16

Which line of evidence supports the protein-first hypothesis?

Accepted Answer

A)  Amino acids existed on prebiotic Earth and in meteorites. 
B)  Proteins display more chemical diversity than nucleic acids. 
C)  Proteins display more structural diversity than nucleic acids. 
D)  Protein function can be reproduced in a population. 
E)  Nucleic acids are too simple to have been the first "polymers of life." 
A)  Amino acids existed on prebiotic Earth and in meteorites. 
B)  Proteins display more chemical diversity than nucleic acids. 
C)  Proteins display more structural diversity than nucleic acids. 
D)  Protein function can be reproduced in a population. 
E)  Nucleic acids are too simple to have been the first "polymers of life."

Question 17

The final step in the development of eukaryotic cells was likely ____.

Accepted Answer

A)  duplication of function in the endosymbiont and host cell 
B)  transfer of genes and function from the endosymbiont to the host cell 
C)  circularization of DNA 
D)  formation of membrane-bound organelles 
E)  ingestion of photosynthetic bacteria 
A)  duplication of function in the endosymbiont and host cell 
B)  transfer of genes and function from the endosymbiont to the host cell 
C)  circularization of DNA 
D)  formation of membrane-bound organelles 
E)  ingestion of photosynthetic bacteria

Question 18

One function provided by cell membranes is ____.

Accepted Answer

A)  the free passage of materials into and out of the cell 
B)  the exclusion of nucleic acids 
C)  structural integrity 
D)  protection from parasitic genetic information 
E)  to counteract size restrictions 
A)  the free passage of materials into and out of the cell 
B)  the exclusion of nucleic acids 
C)  structural integrity 
D)  protection from parasitic genetic information 
E)  to counteract size restrictions

Question 19

If life evolved in hydrothermal vents, is it likely the first cells were in the Domain Archaea?

Accepted Answer

Not necessarily. Organisms found in hydr

Question 20

Evidence for the endosymbiotic theory includes ____.

Accepted Answer

A)  RNA in prokaryotes, mitochondria, and chloroplasts arranged in a single, circular genome 
B)  endocytosed cells observed to survive in the cytoplasm of the host cell 
C)  endocytosed organelles observed to survive free in the environment 
D)  fossils of prokaryotic cells in the process of endocytosing cyanobacteria 
E)  rRNA sequences that are unique to prokaryotes, mitochondria, and chloroplasts 
A)  RNA in prokaryotes, mitochondria, and chloroplasts arranged in a single, circular genome 
B)  endocytosed cells observed to survive in the cytoplasm of the host cell 
C)  endocytosed organelles observed to survive free in the environment 
D)  fossils of prokaryotic cells in the process of endocytosing cyanobacteria 
E)  rRNA sequences that are unique to prokaryotes, mitochondria, and chloroplasts

Exam 25: The Origin of Life

Ribozymes may have originally developed by ____.

Fatty acids and ribozymes are incompatible as early molecules of life because ____.

Most scientists believe that prokaryotes evolved from eukaryotes .

The ancestor of the three domains of life was ____.

Why is the absence of atmospheric oxygen (O2) so important to the Oparin-Haldane hypothesis?

Protocells likely grew within microscopic compartments in porous alkaline vent chimneys, where ____.

The ____ provides evidence that RNA molecules generated the first proteins.

E ukaryotic evolution relied on ____.

What key assumption of the endosymbiotic theory is observed in living animals?

The earliest evidence of biochemical reactions by living cells dates to about ____ billion years ago.

Stromatolites are fossils of ancient, photosynthetic cyanobacteria .

The first truly living cells must have been prokaryotic in structure .

The Sun provided ____ in order to power the development of life on early Earth.

Molecules that are able to store and reproduce genetic information are known generally as ____.

One criticism of the Miller-Urey experiment among scientists is it ____.

Which line of evidence supports the protein-first hypothesis?

The final step in the development of eukaryotic cells was likely ____.

One function provided by cell membranes is ____.

If life evolved in hydrothermal vents, is it likely the first cells were in the Domain Archaea?

Evidence for the endosymbiotic theory includes ____.

Introduction to Biological Concepts and Research

Life, Chemistry, and Water

Biological Molecules: the Carbon Compounds of Life

Cells

Membranes and Transport

Energy, Enzymes, and Biological Reactions

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

Cell Division and Mitosis

Meiosis: the Cellular Basis of Sexual Reproduction

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Expression: From Dna to Protein

Regulation of Gene Expression

Bacterial and Viral Genetics

Dna Technology: Making and Using Genetically Altered Organisms, and Other Applications

Genomes and Proteomes

The Development of Evolutionary Thought

Microevolution: Genetic Changes Within Populations

Speciation

Paleobiology and Macroevolution

Systematic Biology: Phylogeny and Classification

Prokaryotes and Viruses

Protists

Seedless Plants

Seed Plants

Fungi

Animal Phylogeny, Acoelomates, and Protostomes

Deuterostomes: Vertebrates and Their Closest Relatives

The Plant Body

Transport in Plants

Plant Nutrition

Reproduction and Development in Flowering Plants

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Information Flow and the Neuron

Nervous Systems

Sensory Systems

The Endocrine System

Muscles, Bones, and Body Movements

The Circulatory System

Defenses Against Disease

Gas Exchange: the Respiratory System

Digestive Systems and Animal Nutrition

Regulating the Internal Environment: Osmoregulation, Excretion, and Thermoregulation

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

Filters

Why is the absence of atmospheric oxygen (O₂) so important to the Oparin-Haldane hypothesis?