Biology 191 Chapter 1, 23-27

-Most causes of speciation are relatively slow in that they may take many generations to see changes, with the exception of ________. -polyploidy -natural selection -reinforcement -colonization

polyploidy

The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the question. Species D is pathogenic if it gains access to the human intestine. Which other species, if it coinhabited a human intestine along with species D, is most likely to become a recombinant species that is both pathogenic and resistant to some antibiotics? -species A -species E -species B -species C

species C

The following table depicts characteristics of five prokaryotic species (A-E).Use the information in the table to answer the question. Which species might include cells that are Hfr cells? -species A -species D species C -species B

species D

Covid variants are named when the surface proteins (antigens) are significantly different than those previously recorded. The rapid tests detect antigens, so as the virus mutates -tests get mailed to US households -tests become cheaper -false negatives become more common -the tests may need to be redesigned

-false negatives become more common -the tests may need to be redesigned

You want to study divergence of populations, and you need to maximize the rate of divergence to see results within the period of your grant funding. You will form a new population by taking some individuals from a source population and isolating them so the two populations cannot interbreed. What combination of characteristics would maximize your chance of seeing divergence in this study? 1.Choose a random sample of individuals to form the new population. 2.Choose individuals from one extreme to form the new population. 3.Choose a species to study that produces many offspring. 4.Choose a species to study that produces a few, large offspring. 5.Place the new population in the same type of environment as the source population. 6.Place the new population in a novel environment compared to that of the source population. -2, 3, and 5 -2, 3, and 6 -1, 3, and 6 -1, 4, and 6

2, 3, and 6

Rank the following in order from most general to most specific. 1. gametic isolation 2. reproductive isolating mechanism 3. sperm-egg incompatibility in sea urchins 4. prezygotic isolating mechanism -4, 2, 1, 3 -2, 4, 1, 3 -4, 1, 2, 3 -

2, 4, 1, 3

Use the following description to answer the question.On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. Which two of the following have operated to increase divergence between mosquitofish populations on Andros? 1. improved gene flow 2. bottleneck effect 3. sexual selection 4. founder effect 5. natural selection -2 and 3 -3 and 5 -2 and 4 -1 and 3

3 and 5

Refer to the following information to answer the question. Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. The animal 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. Some 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. 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 -4, 1, 3, 2, 5 -4, 3, 1, 5, 2 -4, 1, 2, 3, 5 -4, 3, 2, 1, 5

4,3,1,5,2

You are the lucky student of a wacky professor who develops a time machine. He asks if you will test it with him. You get in, and there is an immediate glitch—the date readout fails so that when you land, you are not sure what era you are in. As your time machine lands, you see an unusual landscape before you. As you open the door, you realize you cannot breathe. You quickly shut the door, realizing you are in the ________. -Cambrian period -Mesozoic era -Cenozoic era -Archaean eon

Archaean eon

Use the following description to answer the question. In the oceans on either side of the Isthmus of Panama are 30 species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are 15 species on the Pacific side and 15 different species on the Atlantic side. The Isthmus of Panama started rising about 10 million years ago. The oceans were completely separated by the isthmus about 3 million years ago. In the figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest. The Panama Canal was completed in 1914, and its depth is about 50 feet. After 1914, snapping shrimp species from which habitats should be most likely to form hybrids as the result of the canal? -A1 and B1 -A3 and B3 -A5 and B5 -A1-A3 and B1-B3 have equal likelihoods of harboring snapping shrimp species that can hybridize.

A1 and B1

Which statement about variation is true? -All new alleles are the result of nucleotide variability. -All nucleotide variability results in neutral variation. -All phenotypic variation is the result of genotypic variation. -All genetic variation produces phenotypic variation.

All new alleles are the result of nucleotide variability.

Use the following description to answer the question.In the oceans on either side of the Isthmus of Panama are 30 species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are 15 species on the Pacific side and 15 different species on the Atlantic side. The Isthmus of Panama started rising about 10 million years ago. The oceans were completely separated by the isthmus about 3 million years ago.In the figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest. In which habitat should one find snapping shrimp most closely related to shrimp that live in habitat A4? -either A3 or A5 -A5 -B4 -A3

B4

Why does the fitness of a phenotype depend on frequency-dependent selection? -Because selection favors the least common phenotype. -Because the least number of alleles are at that locus. -Because sexual selection produces dimorphism. -Because frequency-dependent selection acts against extreme phenotypes.

Because frequency-dependent selection acts against extreme phenotypes.

Why does the fitness of a phenotype depend on frequency-dependent selection? -Because sexual selection produces dimorphism -Because frequency-dependent selection acts against extreme phenotypes. -Because the least number of alleles are at that locus. -Because selection favors the least common phenotype.

Because frequency-dependent selection acts against extreme phenotypes.

Which listing of geological periods is in the correct order, from oldest to most recent? -Cambrian, Permian, Devonian, Cretaceous -Permian, Cambrian, Cretaceous, Devonian -Cambrian, Devonian, Permian, Cretaceous -Devonian, Cambrian, Permian, Cretaceous

Cambrian, Devonian, Permian, Cretaceous

Which period had the greatest increase in the number of extant species? -Cenozoic -Permian -Paleozoic -Mesozoic

Cenozoic

What concept explains the evolution of complex eyes? -Mollusc eye's evolution was dependent on vertebrate eye evolution. -Through evolutionary history, eyes lose function of vision. -Complex eyes evolved through a series of steps that benefited the eyes. -Mollusc eyes evolved from a different ancestor than vertebrate eyes.

Complex eyes evolved through a series of steps that benefited the eyes.

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. -Conditions 1 and 2 -Condition 2 only -Condition 1 only -Conditions 2 and 3

Conditions 1 and 2

Use the following information to answer the question. Refer to the figure. Which of the following forms a monophyletic group? -D, E, and F -A, B, C, D -E, F, and G -C and D

E, F, and G

Data were collected from the heterocysts of a nitrogen-fixing cyanobacterium inhabiting equatorial ponds. Study the graph and choose the most likely explanation for the shape of the curve. -Heterocyst walls become less permeable to nitrogen (N2) influx during darkness. -Enough oxygen (O2) enters heterocysts during hours of peak photosynthesis to have a somewhat inhibitory effect on nitrogen fixation. -Atmospheric nitrogen (N2) levels increase at night because plants are no longer metabolizing this gas, so they are not absorbing this gas through their stomata. -The amount of fixed nitrogen that is dissolved in the pond water in which the cyanobacteria are growing peaks at the close of the photosynthetic day (1800 hours).

Enough oxygen (O2) enters heterocysts during hours of peak photosynthesis to have a somewhat inhibitory effect on nitrogen fixation.

According to the theory of seafloor spreading, oceanic islands, such as the Hawaiian Islands, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven large islands that has active volcanoes. What should be true of the island of Hawaii? I) Scientists in search of ongoing speciation events are more likely to find them here than on the other six large islands. II) Its species should be more closely related to those of nearer islands than to those of farther islands. III) It should have a rich fossil record of terrestrial organisms. IV) It should have species that are not found anywhere else on Earth. V) On average, it should have fewer species per-unit surface area than the other six islands. -I, II, III and IV -I, II and V -I, II, IV and V -I, II and III

I, II, IV and V

Which of the following is the correct sequence of events in the origin of life? I. Formation of protocells II. Synthesis of organic monomers III. Synthesis of organic polymers IV. Formation of DNA-based genetic systems -I, III, II, IV -II, III, I, IV -II, III, IV, I -I, II, III, IV

II, III, I, IV

The following question refers to the following phylogenetic trees. Which tree depicts the closest relationship between zygomycetes and chytrids? -IV -II -I -III

III

Chloramphenicol is an antibiotic that targets prokaryotic (70S) ribosomes, but not eukaryotic (80S) ribosomes. Which of these questions stems from this observation, plus an understanding of eukaryotic origins? -Can chloramphenicol also be used to control human diseases that are caused by archaeans? -Can chloramphenicol pass through the capsules possessed by many cyanobacteria? -Why aren't prokaryotic ribosomes identical to eukaryotic ribosomes? -If chloramphenicol inhibits prokaryotic ribosomes, should it not also inhibit mitochondrial ribosomes?

If chloramphenicol inhibits prokaryotic ribosomes, should it not also inhibit mitochondrial ribosomes?

If Darwin had been aware of genes and their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement? -A single mutation in a single gene in a single gamete, if inherited by future generations, will produce a new species. -If an organism acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will result. -If natural selection can change gene frequency in a population over generations, given enough time and genetic diversity, then natural selection can cause sufficient genetic change to produce new species from old ones. -If an organism's somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring.

If natural selection can change gene frequency in a population over generations, given enough time and genetic diversity, then natural selection can cause sufficient genetic change to produce new species from old ones.

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? -Natural selection is rare in wild populations of wild mustard. -Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics. -In wild mustard, most of the variation is due to differences in soil or other aspects of the environment. -In this wild mustard, there is enough heritable variation to permit these different varieties.

In this wild mustard, there is enough heritable variation to permit these different varieties.

Which statement illustrates the connection between natural selection and overreproduction of a population? -Populations vary in their inherited traits. -Species produce more offspring than can survive in the environment. -Individuals with inherited traits that promote survival tend to have more surviving offspring. -Individuals with traits that do not enhance survival cannot reproduce.

Individuals with inherited traits that promote survival tend to have more surviving offspring.

The thermoacidophile Sulfolobus acidocaldarius lacks peptidoglycan, but still possesses a cell wall. Which of the following statements is likely to be an accurate description of this species? -The optimal pH of its enzymes will lie above pH 7. -It is a bacterium. -It could inhabit alkaline hot springs. -It could inhabit hydrothermal springs.

It could inhabit hydrothermal springs.

What is true of the fossil record of mammalian origins? -It includes a series that shows the gradual change of scales into fur. -It includes transitional forms with progressively specialized teeth. -It indicates that mammals and dinosaurs did not overlap in geologic time. -It shows that mammals and birds evolved from the same kind of dinosaur.

It includes transitional forms with progressively specialized teeth.

What must be true of any organ described as vestigial? -It must be both homologous and analogous to some feature in an ancestor. -It must be analogous to some feature in an ancestor. -It need be neither homologous nor analogous to some feature in an ancestor. -It must be homologous to some feature in an ancestor.

It must be homologous to some feature in an ancestor

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.

No; they still can interbreed.

Why would gene duplication events, such as those seen in the Hox gene complex, set the stage for adaptive radiation? -There are more copies of genes, meaning speciation had occurred by polyploidy. -The original gene copy is the outgroup, and the new gene copies are the adaptive radiation. -Without duplicated genes, species would be vulnerable to extinction. -One copy of a gene can perform the original function, while other copies are available to take on new functions.

One copy of a gene can perform the original function, while other copies are available to take on new functions.

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? -These two species are likely in the process of fusing back into one species. -Postzygotic isolation exists between the two frog species. -The hybrids form a separate species under the biological species concept. -Prezygotic isolation exists between the two frog species

Postzygotic isolation exists between the two frog species.

Which of the following statements suggests natural selection as a mechanism in the evolution of ribozymes? -Some strands of RNA replicate less often. -Replication of RNA is flawless. -Single-stranded RNA has many shapes. -Some strands of RNA replicate more often and with more mutations.

Some strands of RNA replicate less often.

Currently, two extant elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true? -Species X and Y share a common ancestor that is alive today. -Species X and Y are the result of artificial selection. -Species X and Y share a greater number of homologies with each other than either does with species Z. -Species X and Y are not related to species Z.

Species X and Y share a greater number of homologies with each other than either does with species Z.

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. The cell also lacks F factors and F plasmids. Which of the following statements about the bacteria is most probably accurate? -The bacterium cannot form an endospore. -The bacterium cannot take up DNA from its external environment. -The bacterium cannot donate DNA through conjugation with another cell. -The bacterium cannot reproduce.

The bacterium cannot donate DNA through conjugation with another cell.

Why are fossils considered to be an incomplete record of evolution? -Fossils document how new organisms come from preexisting organisms. -The fossil record shows that many animals are extinct. -The fossil record is biased for organisms that had hard shells and skeletons. -The fossil record shows changes in kinds of organisms that lived on earth.

The fossil record is biased for organisms that had hard shells and skeletons.

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 that 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? -The percentage of pink flowers should increase over time. -The distribution of flower colors should not change. -The percentage of white flowers should increase over time. -The distribution of flower colors should randomly fluctuate over time.

The percentage of pink flowers should increase over time.

Members of two different species possess a similar-looking structure that they use in a similar way to perform about the same function. Which of the following would suggest that the relationship more likely represents homology instead of convergent evolution? -The two species share many proteins. -The two species live at great distance from each other. -Both species are well adapted to their particular environments. -The structures in adult members of both species are similar in size.

The two species share many proteins.

Which one of the following observations did Darwin first make during his discovery of evolution? -The ability of individuals to survive and reproduce is not equal. -The unequal ability to reproduce leads to the accumulation of favorable traits in a population. -Individuals who reproduce more leave more offspring -There is variation in inherited traits.

There is variation in inherited traits.

Use the following description to answer the question. In the oceans on either side of the Isthmus of Panama are 30 species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are 15 species on the Pacific side and 15 different species on the Atlantic side. The Isthmus of Panama started rising about 10 million years ago. The oceans were completely separated by the isthmus about 3 million years ago. In the figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest. Why should deepwater shrimp on different sides of the isthmus have diverged from each other earlier than shallow-water shrimp? -Fresh water entering the ocean from the canal is both less dense and cloudier than seawater. The cloudy fresh water interferes with the ability of shallow-water shrimp to locate mating partners, which reduces the frequency of mating, thereby slowing the introduction of genetic variation. -The rise of the land bridge was accompanied by much volcanic activity. Volcanic ash contains heavy metals, which are known mutagens. Ash fall caused high levels of heavy metals in the ocean sediments underlying the deep water, resulting in accelerated mutation rates and faster divergence in deepwater shrimp. -They have been geographically isolated from each other for a longer time. -Cold temperatures, associated with deep water, have accelerated the mutation rate, resulting in faster divergence in deepwater shrimp.

They have been geographically isolated from each other for a longer time.

Use the following description to answer the question.In the oceans on either side of the Isthmus of Panama are 30 species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are 15 species on the Pacific side and 15 different species on the Atlantic side. The Isthmus of Panama started rising about 10 million years ago. The oceans were completely separated by the isthmus about 3 million years ago. In the figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest. Why should deepwater shrimp on different sides of the isthmus have diverged from each other earlier than shallow-water shrimp? -Cold temperatures, associated with deep water, have accelerated the mutation rate, resulting in faster divergence in deepwater shrimp. -They have been geographically isolated from each other for a longer time. -Fresh water entering the ocean from the canal is both less dense and cloudier than seawater. The cloudy fresh water interferes with the ability of shallow-water shrimp to locate mating partners, which reduces the frequency of mating, thereby slowing the introduction of genetic variation. -The rise of the land bridge was accompanied by much volcanic activity. Volcanic ash contains heavy metals, which are known mutagens. Ash fall caused high levels of heavy metals in the ocean sediments underlying the deep water, resulting in accelerated mutation rates and faster divergence in deepwater shrimp.

They have been geographically isolated from each other for a longer time.

HIV's genome of RNA includes the code for reverse transcriptase (RT), an enzyme that acts early in infection to synthesize a DNA genome off of an RNA template. The HIV genome also codes for protease (PR), an enzyme that acts later in infection by cutting long viral polyproteins into smaller, functional proteins. Both RT and PR represent potential targets for antiretroviral drugs. Drugs called nucleoside analogs (NA) act against RT, whereas drugs called protease inhibitors (PI) act against PR. Which of the following treatment options would most likely avoid the evolution of drug-resistant HIV (assuming no drug interactions or side effects)? -Use a single PI, but slowly increase the dosage over the course of a week. -Use a series of NAs, one at a time, and change about once a week. -Use high doses of NA and a PI at the same time for a period not to exceed one day. -Use moderate doses of NA and two different PIs at the same time for several months.

Use moderate doses of NA and two different PIs at the same time for several months.

The largest unit within which gene flow can readily occur is ________. -a species -the hybrid zone -the entire range of a genus -a population

a species

HIV's genome of RNA includes the code for reverse transcriptase (RT), an enzyme that acts early in infection to synthesize a DNA genome off of an RNA template. The HIV genome also codes for protease (PR), an enzyme that acts later in infection by cutting long viral polyproteins into smaller, functional proteins. Both RT and PR represent potential targets for antiretroviral drugs. Drugs called nucleoside analogs (NA) act against RT, whereas drugs called protease inhibitors (PI) act against PR.Which of the following treatment options would most likely avoid the evolution of drug-resistant HIV (assuming no drug interactions or side effects)? -Use a single PI, but slowly increase the dosage over the course of a week. -Use moderate doses of NA and two different PIs at the same time for several months. -Use high doses of NA and a PI at the same time for a period not to exceed one day. -Use a series of NAs, one at a time, and change about once a week.

Use moderate doses of NA and two different PIs at the same time for several months.

The following questions refer to the evolutionary tree in the figure below. The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species. Which of the five common ancestors, labeled V-Z, is the common ancestor of the greatest number of species, both living and extinct? -Z -W -Y -V

Y

You are the lucky student of a wacky professor who develops a time machine. He asks if you will test it with him. You get in, and there is an immediate glitch—the date readout fails so that when you land, you are not sure what era you are in. Your professor begins to panic, but you see something that tells you are in the Cenozoic era. Which of the following could it be? -a rabbit eating a daisy -a bee pollinating a flower -masses of green ferns with dragonflies hovering above them -a water lily floating in a pond

a rabbit eating a daisy

In a comparison of birds and mammals, having four limbs is ________. -a character useful for distinguishing birds from mammals -a shared derived character -a shared ancestral character -an example of analogy rather than homology

a shared ancestral character

In a comparison of birds and mammals, having four limbs is ________. -a shared ancestral character -a shared derived character -a character useful for distinguishing birds from mammals -an example of analogy rather than homology

a shared ancestral character

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 ________. -sympatric speciation -reinforcement -allopatric speciation -prezygotic isolation

allopatric speciation

Insect wings may have begun to evolve as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air. Additional selection refined them as flight-producing wings. If this hypothesis is correct, modern insect wings would be an example of ________. -mutations -an exaptation -an adaptive radiation -the loss of Hox genes in the evolution of new form

an exaptation

The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and ________. -a decreasing number of viable, fertile 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 -an increasing number of infertile hybrids is produced over the course of the next 100 generations

an increasing number of viable, fertile hybrids is produced over the course of the next 100 generations

If a bacterium regenerates from an endospore that did not possess any of the plasmids that were contained in its original parent cell, the regenerated bacterium will probably also lack ________. -a chromosome -a cell wall -antibiotic-resistant genes -water in its cytoplasm

antibiotic-resistant genes

Scientific theories ________. -are predictions of future events -are nearly the same things as hypotheses -are supported by, and make sense of, many observations -cannot be tested because the described events occurred only once

are supported by, and make sense of, many observations

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? -genetic -biological -morphological -ecological

biological

The predatory bacterium Bdellovibrio bacteriophorus drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm? -lipopolysaccharide membrane, peptidoglycan, capsule, phospholipid membrane -lipopolysaccharide membrane, capsule, peptidoglycan, phospholipid membrane -phospholipid membrane, capsule, peptidoglycan, lipopolysaccharide membrane -capsule, lipopolysaccharide membrane, peptidoglycan, phospholipid membrane

capsule, lipopolysaccharide membrane, peptidoglycan, phospholipid membrane

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to ________. -prevent the formation of an ozone layer -make it easier to maintain reduced molecules -cause iron in ocean water and terrestrial rocks to rust (oxidize) -change the atmosphere from oxidizing to reducing

cause iron in ocean water and terrestrial rocks to rust (oxidize)

Genetic drift produces variation for evolution when ________. -chance events cause allele frequencies to fluctuate unpredictably -a gene pool decreases because a smaller group establishes a new population -sudden change in environment drastically reduces the gene pool -a population has heritable traits better suited to the environment

chance events cause allele frequencies to fluctuate unpredictably

Genetic drift produces variation for evolution when ________. -chance events cause allele frequencies to fluctuate unpredictably -a population has heritable traits better suited to the environment -sudden change in environment drastically reduces the gene pool -a gene pool decreases because a smaller group establishes a new population

chance events cause allele frequencies to fluctuate unpredictably

Microevolutions occur when ________. -gene flow evenly transfers alleles between populations -individuals within all species vary in their phenotypic traits -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

changes in allele frequencies in a population occur over generations

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of ________. -fungi and animals -chimpanzees and humans -sharks and dolphins -archaeans and bacteria

chimpanzees and humans

Use the following information to answer the question. A sediment core is removed from the floor of an inland sea. The sea has been in existence, off and on, throughout the entire time that terrestrial life has existed. Researchers wish to locate and study the terrestrial organisms fossilized in this core. The core is illustrated as a vertical column, with the top of the column representing the most recent strata and the bottom representing the time when land was first colonized by life. If arrows indicate locations in the column where fossils of a particular type (see key) first appear, then which core in the figure above has the most accurate arrangement of fossils? -core C -core B -core A -core D

core A

Which of the following is the most predictable outcome of increased gene flow between two populations? -increased genetic difference between the two populations -lower average fitness in both populations -decreased genetic difference between the two populations -higher average fitness in both populations

decreased genetic difference between the two populations

Which of the following is the most predictable outcome of increased gene flow between two populations? -lower average fitness in both populations -decreased genetic difference between the two populations -increased genetic difference between the two populations -higher average fitness in both populations

decreased genetic difference between the two populations

Use the following information and graph to answer the question. The figure below depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). What process is occurring at Time C that is decreasing the DNA content? -reversal of the direction of conjugation -crossing over -degradation of DNA that was not retained in the recipient's chromosome -cytokinesis

degradation of DNA that was not retained in the recipient's chromosome

Which of the following is the best modern definition of evolution? -change in the number of genes in a population over time -inheritance of acquired characters -survival of the fittest -descent with modification

descent with modification

Which of the following is the best modern definition of evolution? -inheritance of acquired characters -survival of the fittest -change in the number of genes in a population over time -descent with modification

descent with modification

Which of the following descriptions illustrates phenotype variation caused by environment? -diet of caterpillars changes their morphology -average beak depth during drought -variation in horse coat color -inheritance of body builder "physique"

diet of caterpillars changes their morphology

A biologist doing a long-term study on a wild spider population observes increased variation in silk thickness. Which of the following could the spider population be experiencing? -directional selection -disruptive selection -genetic drift -stabilizing selection

disruptive selection

The following questions refer to the evolutionary tree in the figure below. The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species. How many distinct species, both living and extinct, are depicted in this tree? -eleven -five -nine -six

eleven

Macroevolution is ________. -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 -the same as microevolution, but includes the origin of new species -evolution above the species level

evolution above the species level

Darwin used the phrase "descent with modification" to explain ________. -unity of life -descent of all organisms from a single, ancient ancestor -evolution of the unity and diversity of life -that habitat differences stimulate change in organisms

evolution of the unity and diversity of life

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of ________. -changes in Hox gene expression. -adaptive radiation -exaptation -paedomorphosis

exaptation

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? -heterozygote advantage and stabilizing selection -founder effect and genetic drift -population bottleneck and Hardy-Weinberg equilibrium -mutation and natural selection

founder effect and genetic drift

The restriction enzymes of bacteria protect the bacteria from successful attack by bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated. This situation selects for bacteriophages whose genomes are also methylated. As new strains of resistant bacteriophages become more prevalent, this in turn selects for bacteria whose genomes are not methylated and whose restriction enzymes instead degrade methylated DNA. The outcome of the conflict between bacteria and bacteriophages at any point in time results from ________. -heterozygote advantage -neutral variation -frequency-dependent selection -evolutionary imbalance

frequency-dependent selection

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 further east. What process of population genetics generated these results? -gene drift -nonrandom mating -adaptive evolution -gene flow

gene flow

In hybrid zones where reinforcement is occurring, we should see a decline in ________. -speciation -mutation rates -the genetic distinctness of two gene pools -gene flow between distinct gene pools

gene flow between distinct gene pools

Use the following information to answer the question.About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and South America) formed, dividing marine organisms into Pacific and Caribbean populations. Researchers have examined species of snapping shrimp on both sides of the isthmus. Based on the morphological species concept, there appeared to be seven pairs of species, with one species of each pair in the Pacific and the other in the Caribbean. The different species pairs live at somewhat different depths in the ocean. Using mitochondrial DNA sequences, the researchers estimated phylogenies and found that each of these species pairs, separated by the isthmus, were indeed each other's closest relatives. The researchers investigated mating in the lab and found that many species pairs were not very interested in courting with each other, and any that did mate almost never produced fertile offspring. (Reference: Y. Kondo and A. Kashiwagi. 2004. Experimentally induced autotetraploidy and allotetraploidy in two Japanese pond frogs. Journal of Herpetology 38(3):381-92.) If the isthmus formed gradually rather than suddenly, what pattern of genetic divergence would you expect to find in these species pairs? -greater percentage of difference in DNA sequence between species that inhabit deep water than between species that inhabit shallow water -similar percentages of difference in DNA sequence between all pairs of sister species -smaller percentage of difference DNA sequence between species that inhabit than between shallow water -greater percentage of difference in DNA sequence between species that inhabit shallow water than between species that inhabit deep water

greater percentage of difference in DNA sequence between species that inhabit deep water than between species that inhabit shallow water

Which Variant of H1N1 caused the earliest cases? -group 7(black line) -groups 1, 3, 6 (green line) -group 8 (blue line) -group 11 (red line)

group 7(black line)

Use of synthetic fertilizers often leads to the contamination of groundwater with nitrates. Nitrate pollution is also a suspected cause of anoxic "dead zones" in the ocean. Which of the following might help reduce nitrate pollution? -adding nitrifying bacteria to the soil -adding denitrifying bacteria to the soil -using ammonia instead of nitrate as a fertilizer -growing improved crop plants that have nitrogen-fixing enzymes

growing improved crop plants that have nitrogen-fixing enzymes

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating -habitat isolation -behavioral isolation -gametic isolation -temporal isolation

habitat isolation

Eukaryotes that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their ________. -plasmids -mitochondrial genomes -homologous genes that are highly conserved -homologous genes that are poorly conserved

homologous genes that are highly conserved

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 -the evolution of similar appearance as a result of common function -convergent evolution -the evolution of common structure as a result of common function

homology

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 ________. -the evolution of similar appearance as a result of common function -homology -the evolution of common structure as a result of common function -convergent evolution

homology

Which postzygotic barriers prevent formation of hybrids beyond the first generations? -increased hybrid vulnerability -hybrid gamete isolation -hybrid breakdown -increased hybrid fertility

hybrid breakdown

Reinforcement is most likely to occur when ________. -hybrids have lower fitness than either parent population -the environment is changing -prezygotic isolating mechanisms are in place -gene flow is low

hybrids have lower fitness than either parent population

Homozygotes with two sickle-cell alleles are selected against because of mortality. However, heterozygotes for sickle-cell allele experience little effects of sickle allele and are more likely to survive malaria. The net effect of this exposure produced evolutionary change in areas where malaria is endemic by ________. -distortion of red blood cells -increasing sickle-cell allele frequency -increasing the number of infected mosquitoes -causing sickle-cell allele

increasing sickle-cell allele frequency

Which of the following statements describe the effect of evolution on a population? -increased genetic variation among individuals in a population -increased sexual reproduction in a population -increasingly better match between a population and its environment -increased variation among individuals in a population

increasingly better match between a population and its environment

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that ________. -island forms and mainland forms have identical gene pools -common environments are inhabited by the same organisms -island forms are descended from mainland forms -the island forms and mainland forms are converging

island forms are descended from mainland forms

The greatest number of endemic species is expected in environments that are ________. -easily reached and show little ecological diversity -easily reached and ecologically diverse -isolated and show little ecological diversity -isolated and ecologically diverse

isolated and show little ecological diversity

Use the following information to answer the question. Nitrogenase, the enzyme that catalyzes nitrogen fixation, is inhibited whenever free oxygen (O2) reaches a critical concentration. Consequently, nitrogen fixation cannot occur in cells wherein photosynthesis produces free O2. Consider the colonial aquatic cyanobacterium, Anabaena, whose heterocysts are described as having "...a thickened cell wall that restricts entry of O2 produced by neighboring cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells in exchange for carbohydrates." Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what mechanism might nitrogen-fixing prokaryotes use to protect these enzymes from oxygen? -couple the nitrogen fixation enzymes with photosystem II (the photosystem that splits water) -live only in anaerobic environments -package the nitrogen fixation enzymes in membranes that are impermeable to all gases -package the nitrogen fixation enzymes in membranes that are impermeable to nitrogen gas (N2).

live only in anaerobic environments

Use the following information to answer the question. Nitrogenase, the enzyme that catalyzes nitrogen fixation, is inhibited whenever free oxygen (O2) reaches a critical concentration. Consequently, nitrogen fixation cannot occur in cells wherein photosynthesis produces free O2. Consider the colonial aquatic cyanobacterium, Anabaena, whose heterocysts are described as having "...a thickened cell wall that restricts entry of O2 produced by neighboring cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells in exchange for carbohydrates. "Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what mechanism might nitrogen-fixing prokaryotes use to protect these enzymes from oxygen? -couple the nitrogen fixation enzymes with photosystem II (the photosystem that splits water) -live only in anaerobic environments -package the nitrogen fixation enzymes in membranes that are impermeable to all gases -package the nitrogen fixation enzymes in membranes that are impermeable to nitrogen gas (N2).

live only in anaerobic environments

he following question refers to the figure. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population. Imagine that after generation 20,000, the experimental cells were grown in high-glucose conditions for 20,000 generations (using the same transfer process described). Refer to the y-axis on the graph and predict the fitness of the new lines when tested in low- and high-glucose conditions. -low: 1.6; high: 1.0 -low: 1.6; high: 1.6 -low: 1.0; high: 1.6 -low: 1.0; high: 1.0

low: 1.0; high: 1.0

In 1983, a population of dark-eyed junco birds became established on the campus of the University of California, San Diego (UCSD), which is located many miles from the junco's normal habitat in the mixed-coniferous temperate forests in the mountains. Juncos have white outer tail feathers that the males display during aggressive interactions and during courtship displays. Males with more white in their tail are more likely to win aggressive interactions, and females prefer to mate with males with more white in their tails. Females have less white in their tails than do males, and display it less often. (Pamela J. Yeh. 2004. Rapid evolution of a sexually selected trait following population establishment in a novel habitat. Evolution 58[1]:166-74.)The UCSD campus male junco population tails are about 36% white, whereas the tails of males from nearby mountain populations are about 40-45% white. The founding stock of UCSD birds was likely from the nearby mountain populations because some of those birds overwinter on the UCSD campus each year. Population sizes on the UCSD campus have been reasonably large, and there are significant habitat differences between the UCSD campus and the mountain coniferous forests; UCSD campus has a more open environment (making birds more visible) and a lower junco density (decreasing intraspecific competition) than the mountain forests. Given this information, which of the following evolutionary mechanisms do you think is most likely responsible for the difference between the UCSD and mountain populations? -natural selection -mutation -gene flow -genetic drift

natural selection

The following question refers to the figure. In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population. The cells in the 12 cell lines grown in low-glucose conditions showed the effects of which of the following processes? -conjugation and transformation -natural selection and mutation -gene flow and genetic drift -natural selection and gene flow

natural selection and mutation

The following question is based on the observation that several dozen different proteins comprise the prokaryotic flagellum and its attachment to the prokaryotic cell, producing a highly complex structure. Certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This evidence supports the claim that ________. -bacteria that possess flagella must have lost the ability to pump certain chemicals across their plasma membranes -natural selection can produce new structures by coupling together parts of other structures -the motors of bacterial flagella must have originated in other organisms -natural selection produces organs that will be needed in future environments

natural selection can produce new structures by coupling together parts of other structures

Use the information in the following paragraph to answer the question. A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. In which feature should one be able to locate a complete chromosome of this bacterium? -plasmid -nucleoid -mitochondrion -nucleus

nucleoid

The higher the proportion of loci that are "fixed" in a population, the lower are that population's ________. -nucleotide variability and average heterozygosity -nucleotide variability -chromosome number -average heterozygosity

nucleotide variability and average heterozygosity

In a hypothetical situation, the genes for sex pilus construction and for tetracycline resistance are located on the same plasmid within a particular bacterium. If this bacterium readily performs conjugation involving a copy of this plasmid, then the result should be the ________. -subsequent loss of tetracycline resistance from this bacterium -production of endospores among the bacterium's progeny -rapid spread of tetracycline resistance to other bacteria in that habitat -temporary possession by this bacterium of a completely diploid genome

rapid spread of tetracycline resistance to other bacteria in that habitat

The difference between geographic isolation and habitat differentiation (isolation) is the ________. -relative location of two populations as speciation occurs -amount of genetic variation that occurs among two gene pools as speciation occurs -identity of the kingdom or domain in which these phenomena occur -speed (tempo) at which two populations undergo speciation

relative location of two populations as speciation occurs

The difference between geographic isolation and habitat differentiation (isolation) is the ________. -relative location of two populations as speciation occurs -speed (tempo) at which two populations undergo speciation -amount of genetic variation that occurs among two gene pools as speciation occurs -identity of the kingdom or domain in which these phenomena occur

relative location of two populations as speciation occurs

In a hypothetical environment, fishes called pike-cichlids are visual predators of large, adult algae-eating fish (in other words, they locate their prey by sight). The population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following is least likely to result in the algae-eater population in future generations? -selection for larger female algae-eaters, bearing broods composed of more, and larger, young -selection for drab coloration of the algae-eaters -selection for nocturnal algae-eaters (active only at night) -selection for algae-eaters that become sexually mature at smaller overall body sizes

selection for larger female algae-eaters, bearing broods composed of more, and larger, young

Which of Darwin's ideas had the strongest connection to his reading of Malthus's essay on human population growth? -struggle for existence -variation among individuals in a population -that the ancestors of the Galápagos finches had come from the South American mainland -descent with modification

struggle for existence

Which one of these processes describes bottleneck effect? -transfer of alleles in and out of a population due to movement of fertile individuals -chance events that change allele frequency -alleles transferred to the next generation in portions that differ from previous generation -sudden change in environments that alters gene frequency of a population

sudden change in environments that alters gene frequency of a population

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 ________. -habitat differentiation -the founder effect -a genetic bottleneck -sexual selection

the founder effect

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________. -the way that they generate ATP -their mode of inheritance -their sources of carbon -their electron acceptors

their sources of carbon

Which of the following describe all existing bacteria? -extremophiles, tiny, abundant -pathogenic, omnipresent, morphologically diverse -tiny, ubiquitous, metabolically diverse -morphologically diverse, metabolically diverse, extremophiles

tiny, ubiquitous, metabolically diverse

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? -four strata -one stratum -three strata -two strata

two strata

Jams, jellies, preserves, honey, and other foods with high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment ________. -are unable to swim through these thick and viscous materials -undergo death as a result of water loss from the cell -are unable to metabolize the glucose or fructose, and thus starve to death -are obligate anaerobes

undergo death as a result of water loss from the cell

View the image. (ignore the question about early cause).... In April of 2009 a vaccine that included H1N1 strains from groups 1, 3, 6 was introduced. Did it work? -yes, the vaccine prevented all H1N1 infection -yes, the vaccine prevented green group infection after 2009 -group 7 and 8 were larger due to vaccne of green groups -can not tell from the data presented

yes, the vaccine prevented green group infection after 2009