Question 1

​Mitochondria were incorporated into eukaryotes after chloroplasts.

Accepted Answer

A) True 
 B)False  False

Question 2

Four of the five answers represent likely mechanisms contributing to how life's first building blocks formed. Select the exception.

Accepted Answer

A) lightning-fueled atmospheric reactions 
B) delivery from ancient volcanoes 
C) reactions at hydrothermal vents 
D) delivery from outer space 
E) spontaneous combustion 
A) lightning-fueled atmospheric reactions 
B) delivery from ancient volcanoes 
C) reactions at hydrothermal vents 
D) delivery from outer space 
E) spontaneous combustion E

Question 3

​The oldest multicellular eukaryote, a(n) ____, can be found in the Proterozoic fossil record.

Accepted Answer

A) ​sponge 
B) ​cnidarian 
C) ​annelid 
D) ​cyanobacteria 
E) ​red alga 
A) ​sponge 
B) ​cnidarian 
C) ​annelid 
D) ​cyanobacteria 
E) ​red alga A

Question 4

Oxygen released by ____ accumulated in early Earth's atmosphere and produced the ozone layer.

Accepted Answer

A) archaeans 
B) aerobic bacteria 
C) cyanobacteria 
D) early eukaryotes 
E) protocells 
A) archaeans 
B) aerobic bacteria 
C) cyanobacteria 
D) early eukaryotes 
E) protocells

Question 5

​A protocell is capable of self-replication.

Accepted Answer

A) True 
 B)False

Question 6

Which organism arose first?

Accepted Answer

A) archaea 
B) animals 
C) fungi 
D) plants 
E) protists 
A) archaea 
B) animals 
C) fungi 
D) plants 
E) protists

Question 7

​Cyanobacteria are ultimately responsible for the ozone layer.

Accepted Answer

A) True 
 B)False

Question 8

Metabolism may have begun when ____ within rocks donated electrons to dissolved carbon monoxide (CO), forming organic compounds.

Accepted Answer

A) oxygen 
B) iron sulfide 
C) carbon dioxide 
D) hydrogen gas 
E) ammonia 
A) oxygen 
B) iron sulfide 
C) carbon dioxide 
D) hydrogen gas 
E) ammonia

Question 9

Ribosomes can catalyze formation of peptide bonds. This supports the hypothesis that ____.

Accepted Answer

A) an RNA world preceded DNA-based genomes 
B) RNA can hold more information than DNA 
C) the first protists had RNA as their genetic material 
D) RNA's only role is that of an enzyme 
E) protocells contained DNA 
A) an RNA world preceded DNA-based genomes 
B) RNA can hold more information than DNA 
C) the first protists had RNA as their genetic material 
D) RNA's only role is that of an enzyme 
E) protocells contained DNA

Question 10

All species on Earth today are descended from a cell that lived as early as ____ years ago.

Accepted Answer

A) 570 million 
B) 1.4 billion 
C) 4 billion 
D) more than 5 billion 
E) more than 10 billion 
A) 570 million 
B) 1.4 billion 
C) 4 billion 
D) more than 5 billion 
E) more than 10 billion

Question 11

Who demonstrated the possibility of producing organic compounds from gases and water if the mixture is exposed to sparks from an electrode?

Accepted Answer

A) Miller and Urey 
B) Ballard 
C) Starr 
D) Watson and Crick 
E) Orgel and Crick 
A) Miller and Urey 
B) Ballard 
C) Starr 
D) Watson and Crick 
E) Orgel and Crick

Question 12

Astrobiologists study Earth's ____ to find clues about possible extraterrestrial life.​

Accepted Answer

A) ​oceans 
B) ​mountain tops 
C) ​average conditions 
D) ​extreme habitats 
E) ​hydrothermal vents 
A) ​oceans 
B) ​mountain tops 
C) ​average conditions 
D) ​extreme habitats 
E) ​hydrothermal vents

Question 13

What compound served to contain interacting organic molecules within a protocell?

Accepted Answer

A) lipids 
B) single amino acids 
C) amino acid polymers 
D) RNA 
E) DNA 
A) lipids 
B) single amino acids 
C) amino acid polymers 
D) RNA 
E) DNA

Question 14

What step occurred first in the evolution of life?

Accepted Answer

A) formation of lipid spheres 
B) formation of protein-RNA systems 
C) formation of membrane-bound protocells 
D) self-assembly of organic monomers 
E) formation of ATP 
A) formation of lipid spheres 
B) formation of protein-RNA systems 
C) formation of membrane-bound protocells 
D) self-assembly of organic monomers 
E) formation of ATP

Question 15

There are several proposed mechanisms that could have produced organic monomers. What mechanism involves the formation of organic compounds in interstellar clouds?

Accepted Answer

A) hydrothermal vents 
B) lightening fueled-atmospheric reactions 
C) organic compounds arriving on Earth via meteorites 
D) reactions involving hot water and metal ions from rocks 
E) the aggregation of dust and rock bits that orbited the sun to form Earth 
A) hydrothermal vents 
B) lightening fueled-atmospheric reactions 
C) organic compounds arriving on Earth via meteorites 
D) reactions involving hot water and metal ions from rocks 
E) the aggregation of dust and rock bits that orbited the sun to form Earth

Question 16

In simulations of tidal flat conditions, amino acids form short chains by binding to ____.

Accepted Answer

A) water molecules 
B) clay particles 
C) iron sulfide 
D) rock chambers 
E) hydrothermal vents 
A) water molecules 
B) clay particles 
C) iron sulfide 
D) rock chambers 
E) hydrothermal vents

Question 17

Four of the five answers below were organic compounds included in the Miller and Urey experiment designed to study the early synthesis of organic compounds. Select the exception.

Accepted Answer

A) methane 
B) ammonia 
C) water 
D) oxygen 
E) hydrogen 
A) methane 
B) ammonia 
C) water 
D) oxygen 
E) hydrogen

Question 18

The primitive Earth's atmosphere contained very little to no ____.

Accepted Answer

A) water vapor 
B) free nitrogen 
C) free hydrogen 
D) free oxygen 
E) inert gases 
A) water vapor 
B) free nitrogen 
C) free hydrogen 
D) free oxygen 
E) inert gases

Question 19

What may have been a site for the synthesis of organic molecules on the early Earth with its source of hot water and metal ions from rocks?

Accepted Answer

A) stratified mica crystals 
B) deep sea hydrothermal vents 
C) the bottoms of tidal pools 
D) dried-out mud flats 
E) pockets in lava beds 
A) stratified mica crystals 
B) deep sea hydrothermal vents 
C) the bottoms of tidal pools 
D) dried-out mud flats 
E) pockets in lava beds

Question 20

Once an endosymbiotic relationship was established between a bacteria and a eukaryotic cell, what effect did it have on their genomes?

Accepted Answer

A) The bacteria transferred all of its DNA to the eukaryotic nucleus. 
B) The endosymbiotic relationship did not affect either cell's genome. 
C) The bacteria lost its genome and relied solely on the eukaryotic cell. 
D) Both genomes evolved so that eventually the host and the bacteria became incapable of living independently. 
E) The eukaryotic genome lost some genes whose function could be supported by the bacteria but the bacterial genome did not change. 
A) The bacteria transferred all of its DNA to the eukaryotic nucleus. 
B) The endosymbiotic relationship did not affect either cell's genome. 
C) The bacteria lost its genome and relied solely on the eukaryotic cell. 
D) Both genomes evolved so that eventually the host and the bacteria became incapable of living independently. 
E) The eukaryotic genome lost some genes whose function could be supported by the bacteria but the bacterial genome did not change.

Exam 18: Lifes Origin and Early Evolution

​Mitochondria were incorporated into eukaryotes after chloroplasts.

Four of the five answers represent likely mechanisms contributing to how life's first building blocks formed. Select the exception.

​The oldest multicellular eukaryote, a(n) ____, can be found in the Proterozoic fossil record.

Oxygen released by ____ accumulated in early Earth's atmosphere and produced the ozone layer.

​A protocell is capable of self-replication.

Which organism arose first?

​Cyanobacteria are ultimately responsible for the ozone layer.

Metabolism may have begun when ____ within rocks donated electrons to dissolved carbon monoxide (CO), forming organic compounds.

Ribosomes can catalyze formation of peptide bonds. This supports the hypothesis that ____.

All species on Earth today are descended from a cell that lived as early as ____ years ago.

Who demonstrated the possibility of producing organic compounds from gases and water if the mixture is exposed to sparks from an electrode?

Astrobiologists study Earth's ____ to find clues about possible extraterrestrial life.​

What compound served to contain interacting organic molecules within a protocell?

What step occurred first in the evolution of life?

There are several proposed mechanisms that could have produced organic monomers. What mechanism involves the formation of organic compounds in interstellar clouds?

In simulations of tidal flat conditions, amino acids form short chains by binding to ____.

Four of the five answers below were organic compounds included in the Miller and Urey experiment designed to study the early synthesis of organic compounds. Select the exception.

The primitive Earth's atmosphere contained very little to no ____.

What may have been a site for the synthesis of organic molecules on the early Earth with its source of hot water and metal ions from rocks?

Once an endosymbiotic relationship was established between a bacteria and a eukaryotic cell, what effect did it have on their genomes?

The Science of Biology

Lifes Chemical Basis

Molecules of Life

Cell Structure

Ground Rules of Metabolism

Where It Starts-Photosynthesis

Releasing Chemical Energy

DNA Structure and Function

From DNA to Protein

Control of Gene Expression

How Cells Reproduce

Meiosis and Sexual Reproduction

Patterns in Inherited Traits

Human Inheritance

Biotechnology

Evidence of Evolution

Processes of Evolution

Viruses, Bacteria, and Archaea

The Protists

Plant Evolution

Fungi

Animals I: Major Invertebrate Groups

Animals Ii: the Chordates

Plant Tissues

Plant Nutrition and Transport

Plant Reproduction and Development

Animal Tissues and Organ Systems

Neural Control

Sensory Perception

Endocrine Control

Structural Support and Movement

Circulation

Immunity

Respiration

Digestion and Human Nutrition

Maintaining the Internal Environment

Reproduction and Development

Animal Behavior

Population Ecology

Community Ecology

Ecosystems

The Biosphere

Human Effects on the Biosphere

Filters

Mitochondria were incorporated into eukaryotes after chloroplasts.

The oldest multicellular eukaryote, a(n) ____, can be found in the Proterozoic fossil record.

A protocell is capable of self-replication.

Cyanobacteria are ultimately responsible for the ozone layer.

Astrobiologists study Earth's ____ to find clues about possible extraterrestrial life.