Question 1

Suppose twenty million years from now there are very large flying insects inhabiting Earth.What is the most likely atmospheric change that has occurred?

Accepted Answer

A)  An increase in the oxygen concentration 
B)  A decrease in the carbon dioxide concentration 
C)  An increase in the carbon dioxide concentration 
D)  A decrease in the oxygen concentration 
E)  A decrease in the argon concentration 
A)  An increase in the oxygen concentration 
B)  A decrease in the carbon dioxide concentration 
C)  An increase in the carbon dioxide concentration 
D)  A decrease in the oxygen concentration 
E)  A decrease in the argon concentration

Question 2

Which gases have opposite effects on Earth's climate?

Accepted Answer

A)  Nitrogen and oxygen 
B)  Nitrogen and carbon dioxide 
C)  Carbon dioxide and sulfur dioxide 
D)  Carbon dioxide and oxygen 
E)  Nitrogen and sulfur dioxide. 
A)  Nitrogen and oxygen 
B)  Nitrogen and carbon dioxide 
C)  Carbon dioxide and sulfur dioxide 
D)  Carbon dioxide and oxygen 
E)  Nitrogen and sulfur dioxide.

Question 3

Which statement about oxygen and ancient Earth is true?

Accepted Answer

A)  The atmosphere of early Earth contained almost as much free oxygen as present-day Earth,but most of this oxygen was lost in the Cambrian. 
B)  Early bacteria generated free oxygen as a by-product of the chemical splitting of water. 
C)  The oxygen-generating cyanobacteria have gone extinct. 
D)  Oxygen concentration increased from near zero to near present-day levels in a nearly straight line upwards. 
E)  Early bacteria generated free oxygen as a by-product of the chemical splitting of carbohydrates. 
A)  The atmosphere of early Earth contained almost as much free oxygen as present-day Earth,but most of this oxygen was lost in the Cambrian. 
B)  Early bacteria generated free oxygen as a by-product of the chemical splitting of water. 
C)  The oxygen-generating cyanobacteria have gone extinct. 
D)  Oxygen concentration increased from near zero to near present-day levels in a nearly straight line upwards. 
E)  Early bacteria generated free oxygen as a by-product of the chemical splitting of carbohydrates.

Question 4

Which statement about the geological time scale is false?

Accepted Answer

A)  Geological eras are divided into periods. 
B)  Observations of differences in fossil assemblages in successive strata allowed scientists to estimate boundaries between divisions of time. 
C)  The geological time scale has been modified as new dating methods have been developed. 
D)  The divisions in the geological time scale were initially defined before the ages of rocks or fossils were known. 
E)  We are currently in the Proterozoic eon. 
A)  Geological eras are divided into periods. 
B)  Observations of differences in fossil assemblages in successive strata allowed scientists to estimate boundaries between divisions of time. 
C)  The geological time scale has been modified as new dating methods have been developed. 
D)  The divisions in the geological time scale were initially defined before the ages of rocks or fossils were known. 
E)  We are currently in the Proterozoic eon.

Question 5

Which statement about the Cambrian is false?

Accepted Answer

A)  Arthropods were abundant and diverse during this period. 
B)  There was abundant multicellular terrestrial life. 
C)  Large continents had already formed. 
D)  Oxygen concentrations were approaching current levels. 
E)  It came before the Ordovician. 
A)  Arthropods were abundant and diverse during this period. 
B)  There was abundant multicellular terrestrial life. 
C)  Large continents had already formed. 
D)  Oxygen concentrations were approaching current levels. 
E)  It came before the Ordovician.

Question 6

Paleontologists are investigating gradual climate shifts that took place over the course of a few thousand years 13 million years ago.What was the most likely cause of this shift?

Accepted Answer

A)  Changes in Earth's orbit around the sun 
B)  Increased atmospheric nitrogen from nitrogen fixation 
C)  Increased atmospheric carbon dioxide from burning of fossil fuels 
D)  Changes in oceanic currents 
E)  An asteroid hitting Earth 
A)  Changes in Earth's orbit around the sun 
B)  Increased atmospheric nitrogen from nitrogen fixation 
C)  Increased atmospheric carbon dioxide from burning of fossil fuels 
D)  Changes in oceanic currents 
E)  An asteroid hitting Earth

Question 7

Which statement about the mass extinction at the end of the Cretaceous is false?

Accepted Answer

A)  A meteorite was involved. 
B)  Many marine invertebrates and insect species died out. 
C)  Almost all land animals larger than about 25 kilograms,including dinosaurs,became extinct. 
D)  It was the largest mass extinction in Earth's history. 
E)  It happened immediately before the Tertiary period. 
A)  A meteorite was involved. 
B)  Many marine invertebrates and insect species died out. 
C)  Almost all land animals larger than about 25 kilograms,including dinosaurs,became extinct. 
D)  It was the largest mass extinction in Earth's history. 
E)  It happened immediately before the Tertiary period.

Question 8

Which finding was not known to nineteenth-century geologists?

Accepted Answer

A)  Fossil organisms found in more recent strata resemble modern organisms more than those found in more ancient strata. 
B)  Fossils of similar organisms are found in widely separated places on Earth. 
C)  Radioactivity can be used to determine the age of rocks. 
D)  Certain fossils are always found in younger strata,and certain other fossils are always found in older strata. 
E)  Nineteenth-century geologists knew all of these findings. 
A)  Fossil organisms found in more recent strata resemble modern organisms more than those found in more ancient strata. 
B)  Fossils of similar organisms are found in widely separated places on Earth. 
C)  Radioactivity can be used to determine the age of rocks. 
D)  Certain fossils are always found in younger strata,and certain other fossils are always found in older strata. 
E)  Nineteenth-century geologists knew all of these findings.

Question 9

You are investigating an Ordovician fossil bed.What would you not expect to find there?

Accepted Answer

A)  Arthropods 
B)  Brachiopods 
C)  Vascular plants 
D)  Mollusks 
E)  All of these would be expected in an Ordovician fossil bed. 
A)  Arthropods 
B)  Brachiopods 
C)  Vascular plants 
D)  Mollusks 
E)  All of these would be expected in an Ordovician fossil bed.

Question 10

Rocklike structures formed by the oxygen-generating cyanobacteria are known as

Accepted Answer

A)  strata. 
B)  stromatolites. 
C)  igneous rocks. 
D)  lithospheres. 
E)  rift valleys. 
A)  strata. 
B)  stromatolites. 
C)  igneous rocks. 
D)  lithospheres. 
E)  rift valleys.

Question 11

Which geological period is the most recent (closest to the present)?

Accepted Answer

A)  Devonian 
B)  Cambrian 
C)  Jurassic 
D)  Silurian 
E)  Cretaceous 
A)  Devonian 
B)  Cambrian 
C)  Jurassic 
D)  Silurian 
E)  Cretaceous

Question 12

Which statement about the Ordovician is false?

Accepted Answer

A)  In an undisturbed formation,fossils from this period will be located directly above those from the Cambrian. 
B)  There was a major extinction at the end of this period. 
C)  This was a period of great diversification of marine life. 
D)  The end of this period occurred less than 300 million years ago. 
E)  It is the period immediately before the Silurian. 
A)  In an undisturbed formation,fossils from this period will be located directly above those from the Cambrian. 
B)  There was a major extinction at the end of this period. 
C)  This was a period of great diversification of marine life. 
D)  The end of this period occurred less than 300 million years ago. 
E)  It is the period immediately before the Silurian.

Question 13

Humans and chimpanzees diverged from each other about 6 million years ago.Therefore,of the total time that life has been on Earth,humans and chimpanzees have been separate species for about _______ percent of the time.

Accepted Answer

A)  0.15 
B)  0.75 
C)  1.5 
D)  3 
E)  7.5 
A)  0.15 
B)  0.75 
C)  1.5 
D)  3 
E)  7.5

Question 14

Suppose the half-life of a radioactive isotope is 30,000 years.Of the total amount of that element assimilated by living organisms into their tissues,0.004 percent consists of the radioactive isotope.If you were to find a skeleton of an organism that had 0.0005 percent of the element as the radioactive isotope,it would be estimated to be _______ years old.

Accepted Answer

A)  10,000 
B)  60,000 
C)  90,000 
D)  120,000 
E)  240,000 
A)  10,000 
B)  60,000 
C)  90,000 
D)  120,000 
E)  240,000

Question 15

The most appropriate way to determine the absolute ages of sedimentary rocks thought to be a few million years old would be to use

Accepted Answer

A)  stratigraphy. 
B)  carbon-14 dating. 
C)  uranium-235 dating. 
D)  potassium-40 dating. 
E)  paleomagnetic dating. 
A)  stratigraphy. 
B)  carbon-14 dating. 
C)  uranium-235 dating. 
D)  potassium-40 dating. 
E)  paleomagnetic dating.

Question 16

During which period did the following events occur: recovery of the biota after a major mass extinction,increase in the species richness of invertebrate groups,appearance of the first turtles and frogs,and beginnings of a large radiation of reptiles?

Accepted Answer

A)  Permian 
B)  Cambrian 
C)  Jurassic 
D)  Cretaceous 
E)  Triassic 
A)  Permian 
B)  Cambrian 
C)  Jurassic 
D)  Cretaceous 
E)  Triassic

Question 17

You are investigating a Devonian fossil bed.What would you not expect to find there?

Accepted Answer

A)  Vascular plants 
B)  Flying insects 
C)  Terrestrial fishlike amphibians 
D)  Large tree ferns 
E)  Seed-producing plants 
A)  Vascular plants 
B)  Flying insects 
C)  Terrestrial fishlike amphibians 
D)  Large tree ferns 
E)  Seed-producing plants

Question 18

Based on the experiment in which Drosophila flies were raised in a higher than normal oxygen concentration,which statement is most likely true?

Accepted Answer

A)  Fly body size is constrained because there are not enough alleles that increase body size. 
B)  Fly body size is constrained because alleles that increase body size are selected against at normal oxygen levels. 
C)  At normal oxygen concentration levels,fly body size is under strong directional selection. 
D)  Fly body size would likely increase if flies were raised at lower than normal oxygen concentrations. 
E)  Increased oxygen levels appear to have little effect on fly body size,even after many generations. 
A)  Fly body size is constrained because there are not enough alleles that increase body size. 
B)  Fly body size is constrained because alleles that increase body size are selected against at normal oxygen levels. 
C)  At normal oxygen concentration levels,fly body size is under strong directional selection. 
D)  Fly body size would likely increase if flies were raised at lower than normal oxygen concentrations. 
E)  Increased oxygen levels appear to have little effect on fly body size,even after many generations.

Question 19

The Great Rift Valley formed due to

Accepted Answer

A)  subduction of a continental plate under an oceanic plate. 
B)  subduction of an oceanic plate under a continental plate. 
C)  the collision of two continental plates. 
D)  divergence of continental plates. 
E)  forces unrelated to plate tectonics. 
A)  subduction of a continental plate under an oceanic plate. 
B)  subduction of an oceanic plate under a continental plate. 
C)  the collision of two continental plates. 
D)  divergence of continental plates. 
E)  forces unrelated to plate tectonics.

Question 20

On the morning weather forecast,the meteorologist makes the following two statements: "The temperature in Amherst,Massachusetts,is currently ‒4°C," and "The average temperature of Amherst,Massachusetts,on this day is 7°C." Which interpretation of these statements is correct?

Accepted Answer

A)  Statement 1 describes climate and statement 2 describes weather. 
B)  Statement 1 describes weather and statement 2 describes climate. 
C)  Both statements describe weather,but not climate. 
D)  Both statements describe climate,but not weather. 
E)  Both statements describe weather and climate. 
A)  Statement 1 describes climate and statement 2 describes weather. 
B)  Statement 1 describes weather and statement 2 describes climate. 
C)  Both statements describe weather,but not climate. 
D)  Both statements describe climate,but not weather. 
E)  Both statements describe weather and climate.

Exam 18: The History of Life on Earth

Suppose twenty million years from now there are very large flying insects inhabiting Earth.What is the most likely atmospheric change that has occurred?

Which gases have opposite effects on Earth's climate?

Which statement about oxygen and ancient Earth is true?

Which statement about the geological time scale is false?

Which statement about the Cambrian is false?

Paleontologists are investigating gradual climate shifts that took place over the course of a few thousand years 13 million years ago.What was the most likely cause of this shift?

Which statement about the mass extinction at the end of the Cretaceous is false?

Which finding was not known to nineteenth-century geologists?

You are investigating an Ordovician fossil bed.What would you not expect to find there?

Rocklike structures formed by the oxygen-generating cyanobacteria are known as

Which geological period is the most recent (closest to the present)?

Which statement about the Ordovician is false?

Humans and chimpanzees diverged from each other about 6 million years ago.Therefore,of the total time that life has been on Earth,humans and chimpanzees have been separate species for about _______ percent of the time.

The most appropriate way to determine the absolute ages of sedimentary rocks thought to be a few million years old would be to use

During which period did the following events occur: recovery of the biota after a major mass extinction,increase in the species richness of invertebrate groups,appearance of the first turtles and frogs,and beginnings of a large radiation of reptiles?

You are investigating a Devonian fossil bed.What would you not expect to find there?

Based on the experiment in which Drosophila flies were raised in a higher than normal oxygen concentration,which statement is most likely true?

The Great Rift Valley formed due to

On the morning weather forecast,the meteorologist makes the following two statements: "The temperature in Amherst,Massachusetts,is currently ‒4°C," and "The average temperature of Amherst,Massachusetts,on this day is 7°C." Which interpretation of these statements is correct?

Introduction

The Chemistry and Energy of Life

Nucleic Acids, Proteins, and Enzymes

Cells: the Working Units of Life

Cell Membranes and Signaling

Pathways That Harvest and Store Chemical Energy

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

DNA and Its Role in Heredity

From Dna to Protein: Gene Expression

Regulation of Gene Expression

Genomes

Biotechnology

Genes, Development, and Evolution

Processes of Evolution

Reconstructing and Using Phylogenies

Speciation

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

The Evolution of Plants

The Evolution and Diversity of Fungi

Animal Origins and Diversity

The Plant Body

Plant Nutrition and Transport

Plant Growth and Development

Reproduction of Flowering Plants

Plants in the Environment

Fundamentals of Animal Function

Nutrition and Digestion

Breathing

Circulation

Muscle and Movement

Neurons, Sense Organs, and Nervous Systems

Nervous and Endocrine Control

Water and Salts: Excretion

Animal Reproduction

Animal Development

Immunology: Animal Defense Systems

Animal Behavior

The Distribution of Earths Ecological Systems

Populations

Ecological and Evolutionary Consequences of Interactions Within and Among Species

Ecological Communities

The Global Ecosystem

Filters