Question 1

Approximately how far back in time does the fossil record extend?

Accepted Answer

A) 3)5 million years 
B) 5)0 million years 
C) 3)5 billion years 
D) 5)0 billion years 
A) 3)5 million years 
B) 5)0 million years 
C) 3)5 billion years 
D) 5)0 billion years

Question 2

For many years,scientists believed that almost all animal lineages burst into being during the Cambrian era (just after the end of the Precambrian super eon).However,there have been many recent findings of animal-like fossils and "trace fossils" (fossils of an animal-like organisms movement)from the late Precambrian.Which of the following best explains why it took so long to realize there was animal-like life in the Precambrian?

Accepted Answer

A) Animals from the late Precambrian had soft bodies. 
B) There were many hard-shelled animals in the Cambrian. 
C) The global climate was such that there was poor fossilization in the Precambrian. 
D) There were very few animals during this period. 
A) Animals from the late Precambrian had soft bodies. 
B) There were many hard-shelled animals in the Cambrian. 
C) The global climate was such that there was poor fossilization in the Precambrian. 
D) There were very few animals during this period.

Question 3

The following questions refer to this hypothetical situation.
A female fly,full of fertilized eggs,is swept by high winds to an island far out to sea.She is the first fly to arrive on this island,and the only fly to arrive in this way.Thousands of years later,her numerous offspring occupy the island,but none of them resembles her.There are,instead,several species,each of which eats only a certain type of food.None of the species can fly,for their flight wings are absent,and their balancing organs (in other words,halteres)are now used in courtship displays.The male members of each species bear modified halteres that are unique in appearance to their species.Females bear vestigial halteres.The ranges of all of the daughter species overlap.
-Fly species W,found in a certain part of the island,produces fertile offspring with species Y.Species W does not produce fertile offspring with species X or Z.If no other species can hybridize,then species W and Y

Accepted Answer

A) have genomes that are still similar enough for successful meiosis to occur in hybrid flies. 
B) have more genetic similarity with each other than either did with the other two species. 
C) may fuse into a single species if their hybrids remain fertile over the course of many generations. 
D) Three of the above statements are correct. 
E) Two of the statements above are correct. 
A) have genomes that are still similar enough for successful meiosis to occur in hybrid flies. 
B) have more genetic similarity with each other than either did with the other two species. 
C) may fuse into a single species if their hybrids remain fertile over the course of many generations. 
D) Three of the above statements are correct. 
E) Two of the statements above are correct.

Question 4

Many species of snakes lay eggs.However,in the forests of northern Minnesota where growing seasons are short,only live-bearing snake species are present.This trend toward species that perform live birth in a particular environment is an example of

Accepted Answer

A) natural selection. 
B) sexual selection. 
C) species selection. 
D) goal direction in evolution. 
E) directed selection. 
A) natural selection. 
B) sexual selection. 
C) species selection. 
D) goal direction in evolution. 
E) directed selection.

Question 5

Which of the following factors weaken(s)the hypothesis of abiotic synthesis of organic monomers in early Earth's atmosphere?
1)the relatively short time between intense meteor bombardment and the appearance of the first life-forms
2)the lack of experimental evidence that organic monomers can form by abiotic synthesis
3)uncertainty about which gases comprised early Earth's atmosphere

Accepted Answer

A) 1 only 
B) 2 only 
C) 1 and 2 
D) 1 and 3 
E) 2 and 3 
A) 1 only 
B) 2 only 
C) 1 and 2 
D) 1 and 3 
E) 2 and 3

Question 6

The first genes on Earth were probably

Accepted Answer

A) DNA produced by reverse transcriptase from abiotically produced RNA. 
B) DNA molecules whose information was transcribed to RNA and later translated in polypeptides. 
C) auto-catalytic RNA molecules. 
D) oligopeptides located within protobionts. 
A) DNA produced by reverse transcriptase from abiotically produced RNA. 
B) DNA molecules whose information was transcribed to RNA and later translated in polypeptides. 
C) auto-catalytic RNA molecules. 
D) oligopeptides located within protobionts.

Question 7

The following questions refer to the description and figure below.
The figure represents a cross section of the sea floor through a mid-ocean rift valley,with alternating patches of black and white indicating sea floor with reversed magnetic polarities.At the arrow labelled "I" (the rift valley),the igneous rock of the sea floor is so young that it can be accurately dated using carbon-14 dating.At the arrow labeled "III," however,the igneous rock is about 1 million years old,and potassium-40 dating is typically used to date such rocks.Note: The horizontal arrows indicate the direction of sea-floor spreading,away from the rift valley.
  
-Which section of sea-floor crust should have the thickest layer of overlying sediment,assuming a continuous rate of sediment deposition?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 8

Adaptive radiations can be a direct consequence of four of the following five factors.Select the exception.

Accepted Answer

A) vacant ecological niches 
B) genetic drift 
C) colonization of an isolated region that contains suitable habitat and few competitor species 
D) evolutionary innovation 
E) an adaptive radiation in a group of organisms (such as plants)that another group uses as food 
A) vacant ecological niches 
B) genetic drift 
C) colonization of an isolated region that contains suitable habitat and few competitor species 
D) evolutionary innovation 
E) an adaptive radiation in a group of organisms (such as plants)that another group uses as food

Question 9

If one organ is an exaptation of another organ,then what must be true of these two organs?

Accepted Answer

A) They are both vestigial organs. 
B) They are both homologous organs. 
C) They are undergoing convergent evolution. 
D) They are found together in the same hybrid species. 
E) They have the same function. 
A) They are both vestigial organs. 
B) They are both homologous organs. 
C) They are undergoing convergent evolution. 
D) They are found together in the same hybrid species. 
E) They have the same function.

Question 10

Use the following figure to answer the questions below.
  
-Hawaii is the most southeastern of the seven islands and is also closest to the sea-floor spreading centre from which the Pacific plate originates,which lies about 5600 km further to the southeast.Assuming equal sedimentation rates,what should be the location of the thickest sediment layer and,thus,the area with the greatest diversity of fossils above the oceanic crust?

Accepted Answer

A) between the island of Hawaii and the sea-floor spreading centre 
B) around the base of the island of Hawaii 
C) around the base of Kauai, the oldest of the Hawaiian islands 
D) where the islands are most concentrated (highest number of islands per unit surface area) 
A) between the island of Hawaii and the sea-floor spreading centre 
B) around the base of the island of Hawaii 
C) around the base of Kauai, the oldest of the Hawaiian islands 
D) where the islands are most concentrated (highest number of islands per unit surface area)

Question 11

The following questions refer to this hypothetical situation.
A female fly,full of fertilized eggs,is swept by high winds to an island far out to sea.She is the first fly to arrive on this island,and the only fly to arrive in this way.Thousands of years later,her numerous offspring occupy the island,but none of them resembles her.There are,instead,several species,each of which eats only a certain type of food.None of the species can fly,for their flight wings are absent,and their balancing organs (in other words,halteres)are now used in courtship displays.The male members of each species bear modified halteres that are unique in appearance to their species.Females bear vestigial halteres.The ranges of all of the daughter species overlap.
-If these fly species lost the ability to fly independently of each other as a result of separate mutation events in each lineage,then the flightless condition in these species could be an example of

Accepted Answer

A) adaptive radiation. 
B) species selection. 
C) sexual selection. 
D) allometric growth. 
E) habitat differentiation. 
A) adaptive radiation. 
B) species selection. 
C) sexual selection. 
D) allometric growth. 
E) habitat differentiation.

Question 12

Evolution includes all of the following points with the exception of

Accepted Answer

A) species can undergo species selection just like populations of individuals undergo natural selection. 
B) differential speciation success in macroevolution plays a similar role to differential reproductive success in microevolution. 
C) evolutionary trends result from natural selection. 
D) complex biological structures can evolve through incremental modifications, which benefit the organisms that possess them. 
E) some evolutionary trends are goal oriented. 
A) species can undergo species selection just like populations of individuals undergo natural selection. 
B) differential speciation success in macroevolution plays a similar role to differential reproductive success in microevolution. 
C) evolutionary trends result from natural selection. 
D) complex biological structures can evolve through incremental modifications, which benefit the organisms that possess them. 
E) some evolutionary trends are goal oriented.

Question 13

The following questions refer to the description below.
All animals with eyes or eyespots that have been studied so far share a gene in common.When mutated,the gene Pax-6 causes lack of eyes in fruit flies,tiny eyes in mice,and missing irises (and other eye parts)in humans.The sequence of Pax-6 in humans and mice is identical.There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies,even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago.
-Pax-6 usually causes the production of a type of light-receptor pigment.In vertebrate eyes,though,a different gene (the rh gene family)is responsible for the light-receptor pigments of the retina.The rh gene,like Pax-6,is ancient.In the marine ragworm,for example,the rh gene causes production of c-opsin,which helps regulate the worm's biological clock.Which of these most likely accounts for vertebrate vision?

Accepted Answer

A) The Pax-6 gene mutated to become the rh gene among early mammals. 
B) During vertebrate evolution, the rh gene for biological clock opsin was co-opted as a gene for visual receptor pigments. 
C) In animals more ancient than ragworms, the rh gene(s)coded for visual receptor pigments; in lineages more recent than ragworms, rh has flip-flopped several times between producing biological clock opsins and visual receptor pigments. 
D) Pax-6 was lost from the mammalian genome, and replaced by the rh gene much later. 
A) The Pax-6 gene mutated to become the rh gene among early mammals. 
B) During vertebrate evolution, the rh gene for biological clock opsin was co-opted as a gene for visual receptor pigments. 
C) In animals more ancient than ragworms, the rh gene(s)coded for visual receptor pigments; in lineages more recent than ragworms, rh has flip-flopped several times between producing biological clock opsins and visual receptor pigments. 
D) Pax-6 was lost from the mammalian genome, and replaced by the rh gene much later.

Question 14

Refer to the following information to answer the questions below.
Fossils of Lystrosaurus,a dicynodont therapsid,are most common in parts of modern-day South America,South Africa,Madagascar,India,South Australia,and Antarctica.It apparently lived in arid regions,and was mostly herbivorous.It originated during the mid-Permian period,survived the Permian extinction,and dwindled by the late Triassic,though there is evidence of a relict population in Australia during the Cretaceous period.The dicynodonts had two large tusks,extending down from their upper jaws.The tusks were not used for food gathering,and in some species were limited to males.Food was gathered using an otherwise toothless beak.Judging from the fossil record in sedimentary rocks,these pig-sized organisms were the most common mammal-like reptiles of the Permian period.
-How many of Lystrosaurus' features below can help explain why these organisms fossilized so abundantly?
I.the presence of hard parts,such as tusks
II.its arid environment
III.its persistence across at least two geological eras
IV.its widespread geographic distribution
V.its mixture of reptilian and mammalian features

Accepted Answer

A) only one of these statements 
B) two of these statements 
C) three of these statements 
D) four of these statements 
E) all five of these statements 
A) only one of these statements 
B) two of these statements 
C) three of these statements 
D) four of these statements 
E) all five of these statements

Question 15

If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for which of the following?
I.polynucleotide polymerase with low mismatch error rates
II.polynucleotide polymerases without proofreading capability
III.batteries of efficient polynucleotide repair enzymes
IV.polynucleotide polymerases with proofreading capability
V.polynucleotide polymerases with high mismatch error rates

Accepted Answer

A) I only 
B) I and IV 
C) I, III, and IV 
D) II and V 
E) II, III and V 
A) I only 
B) I and IV 
C) I, III, and IV 
D) II and V 
E) II, III and V

Question 16

If two continents converge and are united,then the collision should cause

Accepted Answer

A) a net loss of intertidal zone and coastal habitat. 
B) the extinction of any species adapted to intertidal and coastal habitats. 
C) an overall decrease in the surface area located in the continental interior. 
D) a decrease in climatic extremes in the interior of the new supercontinent. 
E) the maintenance of the previously existing ocean currents and wind patterns. 
A) a net loss of intertidal zone and coastal habitat. 
B) the extinction of any species adapted to intertidal and coastal habitats. 
C) an overall decrease in the surface area located in the continental interior. 
D) a decrease in climatic extremes in the interior of the new supercontinent. 
E) the maintenance of the previously existing ocean currents and wind patterns.

Question 17

Which of the following steps has not yet been accomplished by scientists studying the origin of life?

Accepted Answer

A) synthesis of small RNA polymers by ribozymes 
B) abiotic synthesis of polypeptides 
C) formation of molecular aggregates with selectively permeable membranes 
D) formation of protocells that use DNA to direct the polymerization of amino acids 
E) abiotic synthesis of organic molecules 
A) synthesis of small RNA polymers by ribozymes 
B) abiotic synthesis of polypeptides 
C) formation of molecular aggregates with selectively permeable membranes 
D) formation of protocells that use DNA to direct the polymerization of amino acids 
E) abiotic synthesis of organic molecules

Question 18

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers.If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests,this might be evidence supporting the claim that

Accepted Answer

A) dinosaurs were as fully endothermal (warm-blooded)as modern birds and mammals. 
B) their feathers originally served as insulation, and only later became flight surfaces. 
C) the earliest reptiles could fly, and the feathers of flightless dinosaurs were vestigial flight surfaces. 
D) the feathers were plucked from the bodies of other adults to provide nest-building materials. 
E) all fossils with feathers are actually some kind of bird. 
A) dinosaurs were as fully endothermal (warm-blooded)as modern birds and mammals. 
B) their feathers originally served as insulation, and only later became flight surfaces. 
C) the earliest reptiles could fly, and the feathers of flightless dinosaurs were vestigial flight surfaces. 
D) the feathers were plucked from the bodies of other adults to provide nest-building materials. 
E) all fossils with feathers are actually some kind of bird.

Question 19

The hypothesis for the origin of eukaryotes through serial endosymbiosis proposes that

Accepted Answer

A) the ancestors of mitochondria were aerobic heterotrophic prokaryotes, while the ancestors of plastids were photosynthetic prokaryotes. 
B) mitochondria and plastids replicate in a manner similar to eukaryotes. 
C) genes in mitochondria and plastids are similar to genes of ancient eukaryotes. 
D) eukaryotes likely evolved from the fusion of small prokaryotic and small eukaryotic cells. 
A) the ancestors of mitochondria were aerobic heterotrophic prokaryotes, while the ancestors of plastids were photosynthetic prokaryotes. 
B) mitochondria and plastids replicate in a manner similar to eukaryotes. 
C) genes in mitochondria and plastids are similar to genes of ancient eukaryotes. 
D) eukaryotes likely evolved from the fusion of small prokaryotic and small eukaryotic cells.

Question 20

What is thought to be the correct sequence of these events,from earliest to most recent,in the evolution of life on Earth?
1)origin of mitochondria
2)origin of multicellular eukaryotes
3)origin of chloroplasts
4)origin of cyanobacteria
5)origin of fungal-plant symbioses

Accepted Answer

A) 4, 3, 2, 1, 5 
B) 4, 1, 2, 3, 5 
C) 4, 1, 3, 2, 5 
D) 4, 3, 1, 5, 2 
E) 4, 3, 1, 2, 5 
A) 4, 3, 2, 1, 5 
B) 4, 1, 2, 3, 5 
C) 4, 1, 3, 2, 5 
D) 4, 3, 1, 5, 2 
E) 4, 3, 1, 2, 5

Exam 25: The History of Life on Earth

Approximately how far back in time does the fossil record extend?

Many species of snakes lay eggs.However,in the forests of northern Minnesota where growing seasons are short,only live-bearing snake species are present.This trend toward species that perform live birth in a particular environment is an example of

The first genes on Earth were probably

Adaptive radiations can be a direct consequence of four of the following five factors.Select the exception.

If one organ is an exaptation of another organ,then what must be true of these two organs?

Evolution includes all of the following points with the exception of

If two continents converge and are united,then the collision should cause

Which of the following steps has not yet been accomplished by scientists studying the origin of life?

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers.If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests,this might be evidence supporting the claim that

The hypothesis for the origin of eukaryotes through serial endosymbiosis proposes that

What is thought to be the correct sequence of these events,from earliest to most recent,in the evolution of life on Earth? 1)origin of mitochondria 2)origin of multicellular eukaryotes 3)origin of chloroplasts 4)origin of cyanobacteria 5)origin of fungal-plant symbioses

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure,Growth,and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons,Synapses,and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

Filters