Question 1

Which of the following most strongly supports the common origin of all life on Earth? All organisms ________.

Accepted Answer

A)  require energy 
B)  use essentially the same genetic code 
C)  reproduce 
D)  show heritable variation 
E)  evolve 
A)  require energy 
B)  use essentially the same genetic code 
C)  reproduce 
D)  show heritable variation 
E)  evolve B

Question 2

The following question is based on information from Frank M. Frey, "Opposing Natural Selection from Herbivores and Pathogens May Maintain Floral-Color Variation in Claytonia virginica (Portulacaceae)," Evolution 58(11), 2004: 2426-37.
Claytonia virginica is a woodland spring herb with flowers that vary from white to pale pink to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink to white flowers, so Claytonia with pink flowers have greater relative fruit set than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. Given no other information, if the researcher removes all slugs from the study population, what do you expect to happen to the distribution of flower colors in the population over time?

Accepted Answer

A)  The percentage of pink flowers should increase over time. 
B)  The percentage of white flowers should increase over time. 
C)  The distribution of flower colors should not change. 
D)  The distribution of flower colors should randomly fluctuate over time. 
A)  The percentage of pink flowers should increase over time. 
B)  The percentage of white flowers should increase over time. 
C)  The distribution of flower colors should not change. 
D)  The distribution of flower colors should randomly fluctuate over time. A

Question 3

Parasitic species tend to have simple morphologies. Which of the following statements best explains this observation?

Accepted Answer

A)  Parasites evolved early, and this is why they have simple morphologies. 
B)  Parasites evolved simple morphologies in order to reproduce successfully in their hosts. 
C)  Simple morphologies convey some advantages in most parasites. 
D)  Parasites have simple morphologies to evade detection by their hosts. 
A)  Parasites evolved early, and this is why they have simple morphologies. 
B)  Parasites evolved simple morphologies in order to reproduce successfully in their hosts. 
C)  Simple morphologies convey some advantages in most parasites. 
D)  Parasites have simple morphologies to evade detection by their hosts. C

Question 4

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

Accepted Answer

A)  Natural selection cannot account for losses but accounts only for new structures and functions. 
B)  Natural selection accounts for these losses by the principle of use and disuse. 
C)  Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. 
D)  The ancestors of these organisms experienced harmful mutations that forced them to lose these structures. 
A)  Natural selection cannot account for losses but accounts only for new structures and functions. 
B)  Natural selection accounts for these losses by the principle of use and disuse. 
C)  Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. 
D)  The ancestors of these organisms experienced harmful mutations that forced them to lose these structures.

Question 5

If you say that a ground squirrel has greater evolutionary fitness than another ground squirrel in the same population, you mean that the animal

Accepted Answer

A)  has a longer life. 
B)  is able to mate more frequently. 
C)  is able to dominate other squirrels to gain access to food. 
D)  has more offspring that survive and reproduce themselves. 
E)  All of the above statements are correct. 
A)  has a longer life. 
B)  is able to mate more frequently. 
C)  is able to dominate other squirrels to gain access to food. 
D)  has more offspring that survive and reproduce themselves. 
E)  All of the above statements are correct.

Question 6

Which of the following is a fitness trade-off (compromise)?

Accepted Answer

A)  In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge. 
B)  Hummingbirds are the best pollinators of certain flowers, but bees are the best pollinators for orchids. 
C)  The strong, thick beak of a woodpecker helps it find insects in trees. 
D)  Turtle shells provide protection but are heavy and burdensome when moving. 
A)  In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge. 
B)  Hummingbirds are the best pollinators of certain flowers, but bees are the best pollinators for orchids. 
C)  The strong, thick beak of a woodpecker helps it find insects in trees. 
D)  Turtle shells provide protection but are heavy and burdensome when moving.

Question 7

The same basic internal organs (kidneys, stomach, heart, lungs) are found in frogs, birds, snakes, and rodents. This is primarily an example of ________.

Accepted Answer

A)  structural homology 
B)  developmental homology 
C)  genetic correlation 
D)  inheritance of acquired characteristics 
A)  structural homology 
B)  developmental homology 
C)  genetic correlation 
D)  inheritance of acquired characteristics

Question 8

The following question(s) refer to the accompanying figure, which shows an outcrop of sedimentary rock whose strata are labeled A-D.  
-If x indicates the location of fossils of two closely related species, then fossils of their most recent common ancestor are most likely to occur in which stratum?

Accepted Answer

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

Question 9

A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do NOT seem to be optimally arranged because ________.

Accepted Answer

A)  natural selection has not had sufficient time to create the optimal design in each case but will do so given enough time 
B)  in many cases, phenotype is determined by genotype and the environment 
C)  though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design 
D)  natural selection is generally limited to modifying structures that were present in previous generations and/or in previous species 
A)  natural selection has not had sufficient time to create the optimal design in each case but will do so given enough time 
B)  in many cases, phenotype is determined by genotype and the environment 
C)  though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design 
D)  natural selection is generally limited to modifying structures that were present in previous generations and/or in previous species

Question 10

Which of the pairs of plant structures below are homologous?

Accepted Answer

A)  oak tree root and leaf 
B)  rose bush stem and flower 
C)  rose bush leaf and oak tree leaf 
D)  There are no homologous plant structures. 
A)  oak tree root and leaf 
B)  rose bush stem and flower 
C)  rose bush leaf and oak tree leaf 
D)  There are no homologous plant structures.

Question 11

The following question(s) are based on information in Hopi E. Hoekstra, Kristen E. Drumm, and Michael W. Nachman, "Ecological Genetics of Adaptive Color Polymorphism in Pocket Mice: Geographic Variation in Selected and Neutral Genes," Evolution 58(6), 2004: 1329-41.  
-Refer to the figure above. In their investigation of natural selection on Mc1r alleles (the gene that determines coat color) in Arizona pocket mice, Hoekstra et al. determined the frequency of the D and d alleles in each population. They also determined the frequency of alleles for two neutral mitochondrial DNA genes (genes that do not affect and are not linked to coat color). Why did the researchers include the mitochondrial DNA genes as part of their experimental design?

Accepted Answer

A)  Allele change for the neutral mitochondrial genes serves as an experimental group and gives information on any general background genetic difference among these populations. 
B)  Allele change for the neutral mitochondrial genes serves as a control and determines coat-color differences among these populations. 
C)  Allele change for the neutral mitochondrial genes serves as an experimental group and gives information on coat-color differences among these populations. 
D)  Allele change for the neutral mitochondrial genes serves as a control and gives information on any general background genetic difference among these populations. 
E)  None of the above answers applies. 
A)  Allele change for the neutral mitochondrial genes serves as an experimental group and gives information on any general background genetic difference among these populations. 
B)  Allele change for the neutral mitochondrial genes serves as a control and determines coat-color differences among these populations. 
C)  Allele change for the neutral mitochondrial genes serves as an experimental group and gives information on coat-color differences among these populations. 
D)  Allele change for the neutral mitochondrial genes serves as a control and gives information on any general background genetic difference among these populations. 
E)  None of the above answers applies.

Question 12

Similar gill pouches in embryos of a chick, human, and cat are an example of ________.

Accepted Answer

A)  structural homology 
B)  developmental homology 
C)  genetic homology 
D)  the inheritance of acquired characters 
A)  structural homology 
B)  developmental homology 
C)  genetic homology 
D)  the inheritance of acquired characters

Question 13

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened?

Accepted Answer

A)  The herbicide company lost its triazine formula and started selling poor-quality triazine. 
B)  Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. 
C)  Triazine-resistant pigweed has less efficient photosynthesis metabolism. 
D)  Triazine-resistant weeds were more likely to survive and reproduce. 
A)  The herbicide company lost its triazine formula and started selling poor-quality triazine. 
B)  Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. 
C)  Triazine-resistant pigweed has less efficient photosynthesis metabolism. 
D)  Triazine-resistant weeds were more likely to survive and reproduce.

Question 14

Vestigial traits and neutral changes in DNA sequences are good examples of ________.

Accepted Answer

A)  adaptation 
B)  acclimation 
C)  convergent traits 
D)  nonadaptive traits 
E)  none of the above 
A)  adaptation 
B)  acclimation 
C)  convergent traits 
D)  nonadaptive traits 
E)  none of the above

Question 15

The following question(s) refer to the accompanying figure, which shows an outcrop of sedimentary rock whose strata are labeled A-D.  
-If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?

Accepted Answer

A)  one stratum 
B)  two strata 
C)  three strata 
D)  four strata 
A)  one stratum 
B)  two strata 
C)  three strata 
D)  four strata

Question 16

After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough T. cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island?

Accepted Answer

A)  evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks 
B)  evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks 
C)  increased variation in beak size and shape over time 
D)  no change in beak size and shape over time 
A)  evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks 
B)  evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks 
C)  increased variation in beak size and shape over time 
D)  no change in beak size and shape over time

Question 17

Use the following information to answer the question below.
In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20 percent of the β hemoglobin alleles in the human gene pool.
The sickle-cell allele is pleiotropic (that is, it affects more than one phenotypic trait). Specifically, this allele affects oxygen delivery to tissues and affects one's susceptibility to malaria. Heterozygous individuals who have one normal and one sickle-cell allele have a phenotype that has both costs and benefits. The cost: Under conditions of low atmospheric oxygen availability, individuals heterozygous for this allele can experience life-threatening sickle-cell "crises." The benefit: Such individuals are less susceptible to malaria. Thus, pleiotropic genes/alleles reveal that ________.

Accepted Answer

A)  new advantageous alleles do not arise on demand 
B)  evolution is limited by historical constraints 
C)  adaptations are often compromises 
D)  chance events can affect the evolutionary history of populations 
A)  new advantageous alleles do not arise on demand 
B)  evolution is limited by historical constraints 
C)  adaptations are often compromises 
D)  chance events can affect the evolutionary history of populations

Question 18

Which piece of evidence supports the hypothesis shown in the "Within the artiodactyls" origin of the whale lineage, suggesting that the whale lineage diverged from the lineage leading to the hippos after the other members of the order Artiodactyla (pigs, camels, etc.) diverged?

Accepted Answer

A)  A phylogeny of fossil cetaceans indicates that a gradual transition occurred between terrestrial forms and aquatic, whale-like forms. 
B)  DNA comparisons show that whales and hippos share more genetic sequences than whales share with other artiodactyls. 
C)  Some modern cetaceans have a vestigial pelvic girdle. 
D)  Whales arose from a terrestrial ancestor about 50 million years ago. 
E)  All artiodactyls other than whales share an unusual ankle bone called the astragalus. 
A)  A phylogeny of fossil cetaceans indicates that a gradual transition occurred between terrestrial forms and aquatic, whale-like forms. 
B)  DNA comparisons show that whales and hippos share more genetic sequences than whales share with other artiodactyls. 
C)  Some modern cetaceans have a vestigial pelvic girdle. 
D)  Whales arose from a terrestrial ancestor about 50 million years ago. 
E)  All artiodactyls other than whales share an unusual ankle bone called the astragalus.

Question 19

About thirteen different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?

Accepted Answer

A)  They should be limited to the six islands that most recently emerged from the sea. 
B)  Their genomes should be more similar to each other than are the genomes of the five tree finch species. 
C)  They should share fewer anatomical homologies with each other than they share with the tree finches. 
D)  The chances of hybridization between two ground finch species should be less than the chances of hybridization between two tree finch species. 
A)  They should be limited to the six islands that most recently emerged from the sea. 
B)  Their genomes should be more similar to each other than are the genomes of the five tree finch species. 
C)  They should share fewer anatomical homologies with each other than they share with the tree finches. 
D)  The chances of hybridization between two ground finch species should be less than the chances of hybridization between two tree finch species.

Question 20

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests?

Accepted Answer

A)  Larger doses of DDT should have been applied from the air, into water, and within the soil. 
B)  All habitats should have received applications of DDT at about the same time. 
C)  The frequency of DDT application should have been higher. 
D)  None of the insect pests would have genetic variations that resulted in DDT resistance. 
E)  DDT application should have been continual. 
A)  Larger doses of DDT should have been applied from the air, into water, and within the soil. 
B)  All habitats should have received applications of DDT at about the same time. 
C)  The frequency of DDT application should have been higher. 
D)  None of the insect pests would have genetic variations that resulted in DDT resistance. 
E)  DDT application should have been continual.

Exam 22: Evolution by Natural Selection

Which of the following most strongly supports the common origin of all life on Earth? All organisms ________.

Parasitic species tend to have simple morphologies. Which of the following statements best explains this observation?

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

If you say that a ground squirrel has greater evolutionary fitness than another ground squirrel in the same population, you mean that the animal

Which of the following is a fitness trade-off (compromise)?

The same basic internal organs (kidneys, stomach, heart, lungs) are found in frogs, birds, snakes, and rodents. This is primarily an example of ________.

The following question(s) refer to the accompanying figure, which shows an outcrop of sedimentary rock whose strata are labeled A-D. -If x indicates the location of fossils of two closely related species, then fossils of their most recent common ancestor are most likely to occur in which stratum?

A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do NOT seem to be optimally arranged because ________.

Which of the pairs of plant structures below are homologous?

Similar gill pouches in embryos of a chick, human, and cat are an example of ________.

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened?

Vestigial traits and neutral changes in DNA sequences are good examples of ________.

The following question(s) refer to the accompanying figure, which shows an outcrop of sedimentary rock whose strata are labeled A-D. -If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?

Which piece of evidence supports the hypothesis shown in the "Within the artiodactyls" origin of the whale lineage, suggesting that the whale lineage diverged from the lineage leading to the hippos after the other members of the order Artiodactyla (pigs, camels, etc.) diverged?

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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