NEW
Font size
Worksheetszzzzzzzzz 6
Total questions: 80
Worksheet time: 40mins
A hybrid zone is properly defined as ________.
an area where the ranges of two closely related species overlap but do not interbreed
an area where mating occurs between members of two closely related species, producing viable offspring
a zone where sterile hybrids form, kept separate by postzygotic barriers
an area where members of two closely related species intermingle, but gene flow is prevented by prezygotic barriers
A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). To compare a specific region of the DNA from a sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing?
SNP analysis
polymerase chain reaction (PCR)
electroporation
gel electrophoresis
According to the biological species concept, for speciation to occur, ________.
the number of chromosomes in the gene pool must change
changes to centromere location or chromosome size must occur
large numbers of genes that affect numerous phenotypic traits must change
at least one gene, affecting one reproductive barrier, must change
According to the punctuated equilibria model,
given enough time, most existing species will branch gradually into new species.
most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.
most evolution occurs in sympatric populations.
speciation is usually due to a single mutation.
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 Tribulus 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?
evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks
evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks
increased variation in beak size and shape over time
no change in beak size and shape over time
Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?
allopatric speciation; ecological isolation
sympatric speciation; habitat differentiation
allopatric speciation; behavioral isolation
sympatric speciation; allopolyploidy
Comparisons of Neanderthal DNA revealed that there are more similarities to non-African DNA than reference sequences from West Africans. Additionally, scientists found that Neanderthal DNA is as closely related to East Asians as to Europeans. This indicates that interbreeding occurred before human migration farther east. What process of population genetics generated these results?
adaptive evolution
gene flow
gene drift
nonrandom mating
Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (for example, cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to ________ in the absence of other factors; the iguanas would then be under ________ selection.
increase; directional
increase; disruptive
decrease; directional
decrease; disruptive
Darwin used the phrase "descent with modification" to explain ________.
the unity of life
modification occurs only when environmental change occurs
that habitat differences stimulate change in organisms
the unity and diversity of life
DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that
humans and chimpanzees share a relatively recent common ancestor.
humans evolved from chimpanzees.
chimpanzees evolved from humans.
convergent evolution led to the DNA similarities.
DNA technology has many medical applications. Which of the following is not done routinely at present?
production of hormones for treating diabetes and dwarfism
analysis of gene expression for more informed cancer treatments
gene editing by the CRISPR-Cas9 system in viable human embryos to correct genetic diseases
prenatal identification of genetic disease alleles
For which one of the following observations were both Lamarck's hypothesis and Darwin's hypothesis in complete agreement?
Use and disuse of organs determines their size in progeny.
Gradual evolutionary change explains why organisms are well-suited to their environments.
Acquired characteristics are inherited.
More complex species are descended from less complex species.
Fossils found in strata reveal that ________.
older strata carry fossils that differ greatly from living organisms
geologic changes occur quickly on Earth
unused body parts decrease in size
innate drive to complexity of life
Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been warm-blooded. The fossils of Thrinaxodon are consistent with the hypothesis that ________.
fossils found in a given area look like the modern species in that same area
the environment where it lived was very warm
mammals evolved from a reptilian ancestor
Antarctica and South Africa separated after Thrinaxodon went extinct
Genetic variation ________.
is created by the direct action of natural selection
arises in response to changes in the environment
must be present in a population before natural selection can act upon the population
tends to be reduced when diploid organisms produce gametes
House finches were found only in western North America until 1939, when a few individuals were released in New York City. These individuals established a breeding population and gradually expanded their range. The western population also expanded its range somewhat eastward, and the two populations have recently come in contact. If the two forms were unable to interbreed when their expanding ranges met, it would be an example of ________.
prezygotic isolation
reinforcement
allopatric speciation
sympatric speciation
How have DNA microarrays made a huge impact on genomic studies?
They can be used to eliminate the function of any gene in the genome.
They can be used to introduce entire genomes into bacterial cells.
They allow the expression of many or even all of the genes in the genome to be compared at once.
They allow physical maps of the genome to be assembled in a very short time.
How is length of time for speciation estimated?
genetic evidence indicates that species originate
time that elapses when populations of a newly formed species diverge
time it takes for speciation to be complete
speciation precedes divergence
If biological species are defined in terms of reproductive compatibility, the formation of a new species hinges on ________.
gene flow
reproductive isolation
hybrid formation
gene pool expansion
If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics?
These genes would be maintained in case the antibiotics appear.
These bacteria would be outcompeted and replaced by bacteria that have lost these genes.
These bacteria would try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present.
The number of genes conveying antibiotic resistance would increase in these bacteria.
In 1986, a nuclear power accident in Chernobyl, USSR (now Ukraine), led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident?
Mutations caused major changes in rodent physiology over time.
Mutation led to increased genetic variation.
Mutation caused genetic drift and decreased fitness.
Mutation caused the fixation of new alleles.
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?
0.09
0.49
0.9
9.0
In animals, what is the difference between reproductive cloning and therapeutic cloning?
Reproductive cloning uses totipotent cells, whereas therapeutic cloning does not.
Reproductive cloning uses embryonic stem cells, whereas therapeutic cloning does not.
Therapeutic cloning uses nuclei of adult cells transplanted into enucleated unfertilized eggs.
Therapeutic cloning supplies cells for repair of diseased or injured organs.
In DNA technology, the term vector can refer to
the enzyme that cuts DNA into restriction fragments.
the sticky end of a DNA fragment.
a SNP marker.
a plasmid used to transfer DNA into a living cell.
In hybrid zones where reinforcement is occurring, we should see a decline in ________.
gene flow between distinct gene pools
speciation
the genetic distinctness of two gene pools
mutation rates
In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population?
0.36
0.64
0.75
0.80
In recent times, it has been shown that adult cells can be induced to become pluripotent stem cells (iPS). To make this conversion, what has been done to the adult cells?
A retrovirus is used to introduce four specific master regulatory genes.
The adult stem cells must be fused with embryonic cells.
Cytoplasm from embryonic cells is injected into the adult cells.
The nucleus of an embryonic cell is used to replace the nucleus of an adult cell.
In the form of gene therapy used successfully for severe combined immunodeficiency syndrome, SCID-X1, how is the genetic engineering of human cells achieved?
by injecting engineered viruses into the patient's bloodstream
by injecting engineered viruses into the patient's bone marrow
by treating a relative's cultured bone marrow cells with genetically engineered viruses and then injecting these cells into the patient's bone marrow
by isolating the patient's bone marrow cells, infecting them with genetically engineered viruses, and injecting them back into the patient's bone marrow
In the formula for determining a population's genotype frequencies, the "pq" in the term 2pq is necessary because ________.
the population is diploid
heterozygotes can come about in two ways
the population is doubling in number
heterozygotes have two alleles
Macroevolution is ________.
the same as microevolution, but includes the origin of new species
evolution above the species level
defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye
defined as a change in allele or gene frequency over the course of many generations
Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?
habitat isolation
temporal isolation
behavioral isolation
gametic isolation
Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________.
convergent evolution
a homologous structure
natural selection
a vestigial trait
Microevolutions occur when ________.
a bird has a beak of a particular size that does not grow larger during a drought
changes in allele frequencies in a population occur over generations
gene flow evenly transfers alleles between populations
individuals within all species vary in their phenotypic traits
Most causes of speciation are relatively slow in that they may take many generations to see changes, with the exception of ________.
polyploidy
reinforcement
colonization
natural selection
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the following terms best describes this situation?
directional selection
stabilizing selection
disruptive selection
sexual selection
Natural selection changes allele frequencies because some ________ survive and reproduce better than others.
alleles
loci
species
individuals
No two people are genetically identical, except for identical twins. The main source of genetic variation among humans is
new mutations that occurred in the preceding generation.
genetic drift.
the reshuffling of alleles in sexual reproduction.
environmental effects.
One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following issues is a possible hindrance that must be overcome in order for this process to work properly?
prevention of transmission of plant allergens to the vaccine recipients
prevention of vaccine-containing plants being consumed by insects
use of plant cells to translate non-plant-derived mRNA
inability of the human digestive system to accept plant-derived protein
One predicted aspect of climate change is that climates, including precipitation and temperature, over most of Earth will become more variable. Which of the following is a good strategy for genetically engineering crops if this is true?
Use only plant crops that are genetically engineered.
Genetically engineer most crops to withstand very long droughts.
Genetically engineer several genotypes within single crop types.
Genetically engineer the fastest growing crops possible.
Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing ________.
nonrandom mating
geographic isolation
genetic drift
gene flow
Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is also found in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following characteristics of this gene?
Pax-6 genes are identical in nucleotide sequence.
PAX-6 proteins have identical amino acid sequences.
Pax-6 shows shared evolutionary ancestry.
PAX-6 proteins are different for formation of different kinds of eyes.
Prior to the work of Lyell and Darwin, the prevailing belief was that Earth is ________.
a few thousand years old, and populations are unchanging
a few thousand years old, and populations gradually change
millions of years old, and populations rapidly change
millions of years old, and populations are unchanging
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. Pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species. These two juniper species are kept separate by ________.
habitat isolation
temporal isolation
gametic isolation
behavioral isolation
Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following safety measures is one that has been adopted by researchers?
Microorganisms used in recombinant DNA experiments must be genetically crippled to ensure that they cannot survive outside of the laboratory.
Genetically modified organisms are not allowed to be part of our food supply.
Transgenic plants are engineered so that the plant genes cannot hybridize.
Experiments involving HIV or other potentially dangerous viruses have been banned.
Soon after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the evolution of life on this new island should have been most strongly influenced by ________.
a genetic bottleneck
sexual selection
habitat differentiation
the founder effect
Speciation ________.
occurs at such a slow pace that no one has ever observed the emergence of new species
occurs only by the accumulation of small genetic changes over vast expanses of time
must begin with the geographic isolation of a small, frontier population
can involve changes to a single gene
Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct?
In this wild mustard, there is enough heritable variation to permit these different varieties.
Natural selection is rare in wild populations of wild mustard.
In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.
Heritable variation is low in wild mustard – otherwise this wild strain would have different characteristics.
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of ________.
homology
convergent evolution
the evolution of common structure as a result of common function
the evolution of similar appearance as a result of common function
The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when they mate among themselves, they are rarely successful in producing offspring. What can you infer from this information?
Postzygotic isolation exists between the two frog species.
Prezygotic isolation exists between the two frog species.
These two species are likely in the process of fusing back into one species.
The hybrids form a separate species under the biological species concept.
The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including those in their original homeland. Which of the following mechanisms likely explains the genetic uniqueness of this population?
population bottleneck and Hardy-Weinberg equilibrium
heterozygote advantage and stabilizing selection
mutation and natural selection
founder effect and genetic drift
The higher the proportion of loci that are "fixed" in a population, the lower are that population's ________.
nucleotide variability
chromosome number
average heterozygosity
nucleotide variability and average heterozygosity
The Linnaeus classification system grouped organisms by ________.
linear hierarchy of the scala naturae
increasingly more general categories
increasingly more complex categories
environmental location
The peppered moth provides a well-known example of natural selection. The light-colored form of the moth was predominant in England before the Industrial Revolution. In the mid-19th century, a dark-colored form appeared. The difference is produced by a dominant allele of one gene. By about 1900, approximately 90% of the moths around industrial areas were dark colored, whereas light-colored moths were still abundant elsewhere. Apparently, birds could readily find the light moths against the soot-darkened background in industrial areas and, therefore, were eating more light moths. Recently, use of cleaner fuels has greatly reduced soot in the landscape, and the dark-colored moths have been disappearing. Should the two forms of moths be considered separate species?
Yes; natural selection has affected the frequency of the two different forms.
Yes; they have completely different coloration.
Yes; they are reproductively isolated based on habitat.
No; they still can interbreed.
The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and ________.
an increasing number of infertile hybrids is produced over the course of the next 100 generations
no reproduction occurs in the hybrid zone
an increasing number of viable, fertile hybrids is produced over the course of the next 100 generations
a decreasing number of viable, fertile hybrids is produced over the course of the next 100 generations
The production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) is an example of ________.
reduced hybrid viability
hybrid breakdown
reduced hybrid fertility
mechanical isolation
The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?
Forelimb evolution was adaptive in people and bats, but not in whales.
Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
Genes mutate faster in whales than in humans or bats.
Whales are not properly classified as mammals.
Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?
a temporal reproductive isolating mechanism
a postzygotic isolating mechanism
a behavioral reproductive isolating mechanism
a gametic reproductive isolating mechanism
What does the biological species concept use as the primary criterion for determining species boundaries?
geographic isolation
niche differences
gene flow
morphological similarity
Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus, ________.
the allele's frequency should not change from one generation to the next
natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency
two alleles are present in equal proportions
individuals within the population are evolving
Which Hardy-Weinberg condition is affected by population size?
selection
genetic drift
gene flow
no mutation
Which of the following characteristics of Taq polymerase make it useful in the PCR process?
It is heat stable and can withstand the heating step of PCR.
Only minute amounts are needed for each cycle of PCR.
It binds more readily than other polymerases to the primers.
It has regions that are complementary to the primers.
Which of the following correctly lists the processes in order for one cycle of polymerase chain reaction (PCR)?
denature DNA; add fresh enzyme; anneal primers; add dNTPs; extend primers
anneal primers; denature DNA; extend primers
extend primers; anneal primers; denature DNA
denature DNA; anneal primers; extend primers
Which of the following enzymes is required to make complementary DNA (cDNA) from RNA?
endonucleases
helicase
DNA ligase
reverse transcriptase
Which of the following evidence most strongly supports the common origin of all life on Earth? All organisms ________.
require energy
use essentially the same genetic code
reproduce
show heritable variation
Which of the following is not an observation or inference on which natural selection is based?
There is heritable variation among individuals.
Poorly adapted individuals never produce offspring.
Species produce more offspring than the environment can support.
Only a fraction of an individual's offspring may survive.
Which of the following is the best modern definition of evolution?
descent with modification
change in the number of genes in a population over time
survival of the fittest
inheritance of acquired characters
Which of the following is the most predictable outcome of increased gene flow between two populations?
lower average fitness in both populations
higher average fitness in both populations
increased genetic difference between the two populations
decreased genetic difference between the two populations
Which of the following processes is most like the formation of identical twins?
cell cloning
therapeutic cloning
use of adult stem cells
organismal cloning
Which of the following processes uses labeled probes to visualize the expression of genes in whole tissues and organisms?
RT-PCR
in situ hybridization
DNA microarrays
RNA interference
Which of the following statements best explains why modification or change in an organ or tissue during the lifetime of an individual is not inherited?
Characteristics acquired during an organism's life are generally not passed on through genes.
Spontaneous mutations can result in the appearance of new traits.
Only favorable adaptations have survival value.
Disuse of an organ may lead to its eventual disappearance.
Which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells?
Embryonic stem cells only differentiate into only eggs and sperm, and adult stem cells differentiate into any type of cell.
Embryonic stem cells can give rise to all cell types in the organism, and adult stem cells cannot.
Embryonic stem cells can continue to reproduce for an indefinite period, and adult stem cells cannot.
One aim of using embryonic stem cells is to provide cells for repair of diseased tissue.
Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?
genetic
ecological
biological
morphological
Which of these conditions are always true of populations evolving due to natural selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.
Condition 1 only
Condition 2 only
Conditions 1 and 2
Conditions 2 and 3
Which one of the following statements best defines artificial selection?
Process that occurs when individuals inherit traits that enable them to survive and reproduce
Process where humans decide which plants and/or animals will not breed
Process of human directed breeding aimed to produce selective traits in selected species
Process that favors beneficial mutations
Which one of these processes describes bottleneck effect?
chance events that change allele frequency
alleles transferred to the next generation in portions that differ from previous generation
transfer of alleles in and out of a population due to movement of fertile individuals
sudden change in environments that alters gene frequency of a population
Why are yeast cells frequently used as hosts for cloning?
They easily form colonies.
They can remove exons from mRNA.
They do not have plasmids.
They are eukaryotic cells.
Why is it so important to be able to amplify DNA fragments when studying genes?
Before amplification, DNA fragments are likely to bind to RNA and would no longer be able to be analyzed.
A gene may represent only a millionth of the cell's DNA.
Restriction enzymes (endonucleases) cut DNA into fragments that are too small.
A clone requires multiple copies of each gene per clone.
Why might using retroviral vectors for gene therapy increase the patient's risk of developing cancer?
Retroviral vectors may introduce proteins from the virus.
Retroviral vectors do not express the genes that were introduced into a patient's cells.
Retroviral vectors do not integrate their recombinant DNA into the patient's genome.
Retroviral vectors integrate recombinant DNA into the genome in ways that may misregulate the expression of genes at or near the site of integration.
Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S.aureus infections were caused by MRSA. How can this best be explained?
A patient must have become infected with MRSA from another community.
In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug.
Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.
S. aureus evolved to resist vaccines.
Which of the following tools of DNA technology is incorrectly paired with its use?
electrophoresis – separation of DNA fragments
DNA polymerase – polymerase chain reaction to amplify sections of DNA
reverse transcriptase – production of cDNA from mRNA
DNA ligase – cutting DNA, creating sticky ends of restriction fragments
