Question 1

The appearance of Pax-6 in all animals with eyes can be explained in multiple ways.Based on the information given,which explanation is most likely?

Accepted Answer

A) Pax-6 in all of these animals is not homologous;it arose independently in many different animal phyla due to intense selective pressure favoring vision. 
B) The Pax-6 gene is really not one gene.It is many different genes that,over evolutionary time and due to convergence,have come to have a similar nucleotide sequence and function. 
C) The Pax-6 gene was an innovation of an ancestral animal of the early Cambrian period.Animals with eyes or eyespots are descendants of this ancestor. 
D) The perfectly designed Pax-6 gene appeared instantaneously in all animals created to have eyes or eyespots. 
A) Pax-6 in all of these animals is not homologous;it arose independently in many different animal phyla due to intense selective pressure favoring vision. 
B) The Pax-6 gene is really not one gene.It is many different genes that,over evolutionary time and due to convergence,have come to have a similar nucleotide sequence and function. 
C) The Pax-6 gene was an innovation of an ancestral animal of the early Cambrian period.Animals with eyes or eyespots are descendants of this ancestor. 
D) The perfectly designed Pax-6 gene appeared instantaneously in all animals created to have eyes or eyespots.

Question 2

Which of the following statements about the fossil record is correct?

Accepted Answer

A) The fossil record includes more organisms that were abundant,or lived for long periods on Earth,than it is with those that lived for short periods of time and then became extinct. 
B) The fossil record is richer with organisms that are the same ones as currently common and living on Earth today. 
C) The fossil record is richer with organisms that resemble organisms that are those alive today. 
D) A fossil of a rain forest snake would not be found in an area on Earth that is currently a desert. 
A) The fossil record includes more organisms that were abundant,or lived for long periods on Earth,than it is with those that lived for short periods of time and then became extinct. 
B) The fossil record is richer with organisms that are the same ones as currently common and living on Earth today. 
C) The fossil record is richer with organisms that resemble organisms that are those alive today. 
D) A fossil of a rain forest snake would not be found in an area on Earth that is currently a desert.

Question 3

This evolutionary tree shows the influence of speciation and extinction on the diversity of life.After 2 million years,lineage A had a(n)________ rate of speciation and ________ extinction rates compared to lineage B.

Accepted Answer

A) higher;lower 
B) lower;higher 
C) increased;decreased 
D) improved;enhanced 
A) higher;lower 
B) lower;higher 
C) increased;decreased 
D) improved;enhanced

Question 4

A change in the nucleotide sequence of a gene affects function of that gene

Accepted Answer

A) in cells that express that gene. 
B) but is limited to a single cell type. 
C) after gene duplication events. 
D) resulting in paedomorphosis. 
A) in cells that express that gene. 
B) but is limited to a single cell type. 
C) after gene duplication events. 
D) resulting in paedomorphosis.

Question 5

Exaptations

Accepted Answer

A) imply that a structure evolves in anticipation of use. 
B) evolve in one environment but are used for another function. 
C) process new forms by modifying existing forms. 
D) trend toward larger body size. 
A) imply that a structure evolves in anticipation of use. 
B) evolve in one environment but are used for another function. 
C) process new forms by modifying existing forms. 
D) trend toward larger body size.

Question 6

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb.This type of change is illustrative of

Accepted Answer

A) the influence of environment on development. 
B) paedomorphosis. 
C) a change in a developmental gene or in its regulation that altered the spatial organization of body parts. 
D) heterochrony. 
A) the influence of environment on development. 
B) paedomorphosis. 
C) a change in a developmental gene or in its regulation that altered the spatial organization of body parts. 
D) heterochrony.

Question 7

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 8

Figure 23.1
-Assuming that the rate of seafloor spreading was constant during the 1-million-year period depicted in Figure 23.1,what should be the approximate age of marine fossils found in undisturbed sedimentary rock immediately overlying the igneous rock at the arrow labeled II?

Accepted Answer

A) 10,000 years 
B) 250,000 years 
C) 500,000 years 
D) 1,000,000 years 
A) 10,000 years 
B) 250,000 years 
C) 500,000 years 
D) 1,000,000 years

Question 9

Of the following,which is the most abundant source of fossil evidence?

Accepted Answer

A) amber,because a large portion of Earth is vegetated and insects often become trapped in sap 
B) sedimentary rock,because such rock forms in areas sediment moved by water can cause the burial of organisms 
C) mud,because such material is heavy and organisms cannot escape from it easily 
D) ice,because most of Earth has been covered in ice at some point or another 
A) amber,because a large portion of Earth is vegetated and insects often become trapped in sap 
B) sedimentary rock,because such rock forms in areas sediment moved by water can cause the burial of organisms 
C) mud,because such material is heavy and organisms cannot escape from it easily 
D) ice,because most of Earth has been covered in ice at some point or another

Question 10

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate.Adult female bagworm moths are larval in appearance;they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag.This is a good example of

Accepted Answer

A) allometric growth. 
B) paedomorphosis. 
C) sympatric speciation. 
D) adaptive radiation. 
A) allometric growth. 
B) paedomorphosis. 
C) sympatric speciation. 
D) adaptive radiation.

Question 11

If we visualize the time that has passed since the origin of our solar system and Earth,or about 4.6 billion years,as a one-hour clock,then out of one hour,prokaryotes have been present on the planet for about

Accepted Answer

A) 45 minutes. 
B) 15 minutes. 
C) 10 minutes. 
D) 30 seconds. 
E) 3 seconds. 
A) 45 minutes. 
B) 15 minutes. 
C) 10 minutes. 
D) 30 seconds. 
E) 3 seconds.

Question 12

Adaptive radiation

Accepted Answer

A) reduces the size of prosperous ecological communities. 
B) increases extinction rates. 
C) allows new species to occupy different habitats. 
D) observes trends in the fossil record. 
A) reduces the size of prosperous ecological communities. 
B) increases extinction rates. 
C) allows new species to occupy different habitats. 
D) observes trends in the fossil record.

Question 13

Over time,new forms of life have arisen by

Accepted Answer

A) modification of existing structures or existing developmental genes. 
B) sexual selection only. 
C) the process of species living in variable environments with the end goal of mutating and evolving. 
D) the availability of resources after other species go extinct. 
A) modification of existing structures or existing developmental genes. 
B) sexual selection only. 
C) the process of species living in variable environments with the end goal of mutating and evolving. 
D) the availability of resources after other species go extinct.

Question 14

Please use the following information to answer the questions 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.
-Fruit fly eyes are of the compound type,which is structurally very different from the camera-type eyes of mammals.Even the camera-type eyes of molluscs,such as octopi,are structurally quite different from those of mammals.Yet fruit flies,octopi,and mammals possess very similar versions of Pax-6.The fact that the same gene helps produce very different types of eyes is most likely due to

Accepted Answer

A) the few differences in nucleotide sequence among the Pax-6 genes of these organisms. 
B) variations in the number of Pax-6 genes among these organisms. 
C) the independent evolution of this gene at many different times during animal evolution. 
D) differences in the control of Pax-6 expression among these organisms. 
A) the few differences in nucleotide sequence among the Pax-6 genes of these organisms. 
B) variations in the number of Pax-6 genes among these organisms. 
C) the independent evolution of this gene at many different times during animal evolution. 
D) differences in the control of Pax-6 expression among these organisms.

Question 15

If we visualize the time that has passed since the origin of our solar system and Earth,or about 4.6 billion years,as a one-hour clock,then out of one hour,humans have been present on the planet for about

Accepted Answer

A) 30 minutes. 
B) 15 minutes. 
C) 1 minute. 
D) 20 seconds. 
E) 2/10ths of a second. 
A) 30 minutes. 
B) 15 minutes. 
C) 1 minute. 
D) 20 seconds. 
E) 2/10ths of a second.

Question 16

Upon being formed,oceanic islands,such as the Hawaiian Islands,should feature what characteristic,leading to which phenomenon?

Accepted Answer

A) mass extinctions,leading to bottleneck effect 
B) major evolutionary innovations,leading to rafting to nearby continents 
C) a variety of empty ecological niches,leading to adaptive radiation 
D) adaptive radiation,leading to founder effect 
A) mass extinctions,leading to bottleneck effect 
B) major evolutionary innovations,leading to rafting to nearby continents 
C) a variety of empty ecological niches,leading to adaptive radiation 
D) adaptive radiation,leading to founder effect

Question 17

Which of the following is a biological cause of extinctions?

Accepted Answer

A) habitat destruction 
B) change in environment temperature 
C) ocean anoxia 
D) origin of new species 
A) habitat destruction 
B) change in environment temperature 
C) ocean anoxia 
D) origin of new species

Question 18

Larval flies (maggots)express the Ubx gene in all their segments and thereby lack appendages.If this same gene continued to be expressed throughout subsequent developmental stages,except in the head region,and if the result was a fit,sexually mature organism that still strongly resembled a maggot,this would be an example of

Accepted Answer

A) exaptation. 
B) homochrony. 
C) paedomorphosis. 
D) adaptive radiation. 
A) exaptation. 
B) homochrony. 
C) paedomorphosis. 
D) adaptive radiation.

Question 19

If the half-life of carbon-14 is about 5,730 years,then a fossil that has 1/16th the normal proportion of carbon-14 to carbon-12 should be about how many years old?

Accepted Answer

A) 1,400 
B) 2,800 
C) 11,200 
D) 22,900 
A) 1,400 
B) 2,800 
C) 11,200 
D) 22,900

Question 20

What type of genes control how flower petals are arranged or where a set of wings on a bird will develop?

Accepted Answer

A) homeotic genes 
B) paedomorphic genes 
C) gene sequences 
D) convergent genes 
A) homeotic genes 
B) paedomorphic genes 
C) gene sequences 
D) convergent genes

Exam 23: Broad Patterns of Evolution

The appearance of Pax-6 in all animals with eyes can be explained in multiple ways.Based on the information given,which explanation is most likely?

Which of the following statements about the fossil record is correct?

This evolutionary tree shows the influence of speciation and extinction on the diversity of life.After 2 million years,lineage A had a(n)________ rate of speciation and ________ extinction rates compared to lineage B.

A change in the nucleotide sequence of a gene affects function of that gene

Exaptations

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb.This type of change is illustrative of

Figure 23.1 -Assuming that the rate of seafloor spreading was constant during the 1-million-year period depicted in Figure 23.1,what should be the approximate age of marine fossils found in undisturbed sedimentary rock immediately overlying the igneous rock at the arrow labeled II?

Of the following,which is the most abundant source of fossil evidence?

If we visualize the time that has passed since the origin of our solar system and Earth,or about 4.6 billion years,as a one-hour clock,then out of one hour,prokaryotes have been present on the planet for about

Adaptive radiation

Over time,new forms of life have arisen by

If we visualize the time that has passed since the origin of our solar system and Earth,or about 4.6 billion years,as a one-hour clock,then out of one hour,humans have been present on the planet for about

Upon being formed,oceanic islands,such as the Hawaiian Islands,should feature what characteristic,leading to which phenomenon?

Which of the following is a biological cause of extinctions?

If the half-life of carbon-14 is about 5,730 years,then a fossil that has 1/16th the normal proportion of carbon-14 to carbon-12 should be about how many years old?

What type of genes control how flower petals are arranged or where a set of wings on a bird will develop?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Development,stem Cells,and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition,nutrition,and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons,synapses,and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Ecological Communities

Ecosystems and Energy

Conservation Biology and Global Change

Filters

This evolutionary tree shows the influence of speciation and extinction on the diversity of life.After 2 million years,lineage A had a(n) rate of speciation and extinction rates compared to lineage B.