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BSC2011
Midterm- Chapter 22-30
| Question | Answer |
|---|---|
| Which of the following is not an observation or inference that Darwin made while developing his theory of evolution? | Interactions between individuals and their environments cause individuals to evolve. |
| Darwin’s explanation of how adaptations arise centered on __________. | Natural selection |
| Which of the following is correct regarding natural selection? | -Natural selection is a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do individuals without those traits. -Over time, natural selection can increase the correspondence between organism |
| What does each branch point on an evolutionary tree represent? | The common ancestor of the lineages beginning there and to the right of it |
| Which of the following people developed the idea known as the scala naturae, or scale of nature? | Aristotle |
| Darwin originally defined evolution as __________. | descent with modification |
| The modern idea of extinction as a common occurrence in Earth's history was first proposed in the early 19th century writings of __________. | Cuvier |
| The bacteria Staphylococcus aureus has developed resistance to some antibiotic drugs. How did this resistance come about? | Some members of the bacteria populations possessed some sort of genetic variation for antibiotic resistance that was selected for when the bacteria was exposed to the drugs. |
| In Darwin's view of descent with modification, __________. | natural selection can improve the match between an organism and its environment |
| Homologies that appear to have marginal, if any, importance to an organism are called __________. | vestigial structures |
| Which of the following is not an observation or inference on which natural selection is based? | Poorly adapted individuals never produce offspring. |
| A(n) __________ is the smallest unit that can evolve. | population |
| Paleontology, the study of fossils, was developed by __________. | Georges Cuvier |
| A population of zooplankton is exposed to a small number of predatory fish that feed on the larger-sized (adult) zooplankton. Which of the following predictions would most likely occur based on the principles of natural selection? | Adult zooplankton will start to reach sexual maturity when they are still relatively small. |
| On an evolutionary tree, __________. | homologous characteristics form a nested pattern |
| Animals that possess homologous structures probably __________. | evolved from the same ancestor |
| At the time Darwin voyaged on the HMS Beagle, the popularly accepted theory in Western culture that explained the origin of Earth's plants and animals held that the various species __________. | had been created by divine intervention a few thousand years before |
| Organisms found only in specific places in the world are referred to as __________. | endemic |
| 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 an | Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. |
| How did Hutton and Lyell’s ideas influence Charles Darwin’s thinking? | Darwin reasoned that the Earth must be very old and that slow, subtle processes could produce substantial biological changes. |
| Even though rodents known as sugar gliders and flying squirrels are members of distinctly different groups of organisms and live on different continents, they possess similar characteristics. This is an example of __________. | convergent evolution |
| All known organisms transcribe genetic information to protein molecules via the same genetic code. This finding strongly supports the hypothesis that __________. | all organisms are descended from a single common ancestor |
| What does it mean to describe evolution as a scientific theory? | Evolution is a broad model that is supported by many observations and much experimental evidence. |
| During periods of rapid environmental change, what may happen to a species that was well-suited to the former environment? | -The species may go extinct. -Individuals with particular traits that provide an advantage in the new environment will have higher reproductive success. -The population may change so much in adapting to the new environment that it is considered a new sp |
| Adaptations are defined as __________. | inherited characteristics of organisms that enhance their survival and reproduction in specific environments |
| An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms such as hummingbirds, humans, and whales have similar skeletal structures. This most directly suggested to biologists that | dissimilar organisms might have evolved from a distant, common ancestor |
| The breeding of plants and animals for particular traits by humans is called __________. | artificial selection |
| How does our understanding of genetics today refute Lamarck’s principle of the inheritance of acquired characteristics? | Experiments in genetics show that traits acquired during an individual’s lifetime are not inherited in the way proposed by Lamarck. |
| What insight did Darwin gain from reading Thomas Malthus's essay on human suffering? | Organisms have the capacity to overreproduce. |
| Carolus Linnaeus is considered to be the founder of __________, and he __________. | the binomial classification system; thought that resemblances among different species reflected the pattern of their creation |
| An F+ bacterial cell __________. | acts as a donor during conjugation |
| Which subgroup of proteobacteria contains many species that are closely associated with eukaryotic hosts in mutualistic or parasitic relationships? | alpha |
| Bacterial flagella have a very complex structure composed of 42 distinct proteins. What is the most likely explanation for the evolution of these complex structures? | exaptation |
| Which subgroup of proteobacteria contains many species that are predators of other bacteria? | delta |
| The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H2S), accounting for the "rotten egg" smell of swamp muck. Oxygen is a deadly poi | obligately anaerobic chemoheterotroph |
| In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark. Which of the following organisms would be most | Chemoheterotrophic bacteria |
| What is the function of a bacterial endospore? | To facilitate persistence in temporarily harsh environments |
| Bacteria that __________ tend to have abundant internal membranes. | are photosynthetic |
| Which of the following characteristics is a reason why a Gram-stain to distinguish gram-positive from gram-negative bacteria is an important tool in a medical diagnosis of a bacterial infection? | -The cell walls of many gram-negative bacteria are toxic. -The outer membrane of a gram-negative bacterium helps protect it from the body’s defenses. -Certain gram-positive bacteria are resistant to antibiotics. |
| Which of the following is a structure that bacteria, archaea, and eukaryotes have? | plasma membrane |
| Bacteria function primarily in which ecological role? | -Mutualism -Commensalism -Parasitism -Decomposition |
| Plasmids __________. | -replicate independently of the main chromosome -often contain antibiotic resistance genes -are transferred from one bacterium to another by conjugation -allow bacteria to survive adverse conditions |
| Which group of bacteria is unusual in that they lack peptidoglycan in their cell walls? | Chlamydias |
| Which of the following statements about cyanobacteria is true? | -Some are single cells, whereas others live in filamentous colonies. -They are the only prokaryotes that perform plantlike, oxygenic photosynthesis. -Some species may carry on nitrogen fixation. -It can be said that nitrogen-fixing cyanobacteria are th |
| Which of the following mechanisms is/are (a) means of genetic recombination in prokaryotes? | -Transformation -Transduction -Conjugation |
| Bacteria that use light for their energy source and CO2 for their carbon source are called __________. | photoautotrophs |
| What is a difference between the cell walls of prokaryotes and the cell walls of eukaryotes? | The cell walls of prokaryotes are made of molecules different from those comprising the cell walls of eukaryotes. |
| What is the structural feature of gram-positive bacteria that results in their retaining a crystal violet dye stain and thereby being distinguished from gram-negative bacteria in a Gram-stain technique? | Gram-positive bacteria have thicker cell walls. |
| Portions of the genomes of certain prokaryotic species are very similar to portions of the genomes of distantly related prokaryotes. The process that most likely accounts for this genetic similarity is __________. | horizontal gene transfer |
| Antibiotics administered in human medicine work against bacterial infections by __________. | interfering with an aspect of bacterial metabolism or structure that differs from that of eukaryotic cells |
| Acquiring an R plasmid would allow a bacterium to do what? | Resist antibiotics |
| Some prokaryotes stick to their substrate or to one another by means of hairlike appendages, each called a __________. | fimbria |
| Which of the following is not a true statement concerning bacterial flagella? | Bacterial flagella are homologous to the flagella of eukaryotic cells. |
| Why is salt a good preservative to use for foods such as pork and fish? | Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability to reproduce. |
| Which of the following is not one of the most common prokaryotic cell shapes? | Cuboidal |
| Which of the following is a disease caused by bacteria? | Tuberculosis |
| Prokaryotes found inhabiting the Great Salt Lake would be __________. | extreme halophiles |
| Which of the following does not contribute to bacteria’s ability to evolve rapidly? | Sexual reproduction |
| Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria. | Carbon dioxide, nitrogen, water, light, and some minerals |
| What are biofilms? | Biofilms are cooperative colonies of bacteria. |
| What do a carnivorous dinoflagellate, a parasitic apicomplexan, and a ciliate have in common? | All three have sacs known as alveoli just beneath their plasma membranes. |
| Which example below is a characteristic shared by diplomonads and parabasalids? | Both lack plastids. |
| All of the following are genera of protists that parasitize humans EXCEPT: | Chlamydomonas |
| Which of these groups includes photosynthetic unicellular organisms with flagella and contractile vacuoles? | Euglenids |
| The term mixotroph indicates that a protist __________. | combines photosynthesis and heterotrophic nutrition |
| Protists are best described as which of the following? | Eukaryotes that are not plants, animals, or fungi |
| Organisms are classified as Excavata based on __________. | morphological studies of the cytoskeleton |
| Which protist group is thought to be most closely related to animals? | Choanoflagellates |
| Which of these groups includes unicellular organisms that, due to the structure of their cell walls, can withstand pressures equal to the pressure under each leg of a table supporting an elephant? | Diatoms |
| Which of the following is not a cellular organelle possessed by a protist? | Sporozoite |
| Which protists were once categorized as fungi due to their multinucleate filaments that resemble hyphae? | Oomycetes |
| The holdfast of brown algae functions in __________. | anchoring the algae |
| Which of these groups includes species that produce a substance that is toxic to humans? | Dinoflagellates |
| Molecular data suggest that plastids originated as __________ engulfed by a heterotrophic eukaryote. | Cyanobacteria |
| Parasites of the genus Trypanosoma evade immune responses through what defense? | Frequently changing their surface proteins |
| What is one way in which a cellular slime mold differs from a plasmodial slime mold? | A cellular slime mold is multicellular. |
| Which of the following is not a structure used for locomotion in protists? | -Cilia -Flagella -Pseudopodia -Undulating membrane |
| Which of these groups is characterized by cells that have more than one nucleus? | Ciliates |
| Which of the following does not take place during the process of conjugation? | Reproduction |
| Why have protists been "mixed in" with plants, animals, and fungi under the hypothesis that groups eukaryotes into five supergroups? | Many protists are more closely related to plants, animals, or fungi than they are to each other and recent evidence makes it clear that the former kingdom Protista was paraphyletic. |
| Which of the following is one of the main weaknesses of the proposed classification scheme in which all eukaryotes are divided into five supergroups? | It shows all five supergroups diverging simultaneously from a common ancestor. |
| Green algae are divided into two main groups, the charophytes and the __________. | chlorophytes |
| Apicomplexans are currently assigned to the chromalveolates because __________. | the apicoplast, a modified plastid, appears to be of red algal origin |
| Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for penetrating host cells and tissues? | Apicomplexans |
| Although controversial, chromalveolates are proposed as a clade whose common ancestor __________. | engulfed a photosynthetic red alga in a secondary endosymbiosis event |
| Which of the following is the best description of protists’ contribution to photosynthesis? | About 30% of the world’s photosynthesis is performed by protists. |
| The term algae refers to __________. | several diverse groups of photosynthetic protists |
| __________ is a protist that causes late blight of potatoes and was responsible for the Irish potato famine of the 19th century. | Phytophthora infestans |
| Which organisms are capable of producing a "red tide"? | Dinoflagellates |
| Which of the following is not a group included in the protists? | -Ciliates -Brown algae -Diatoms -Forams |
| Sori can be found in which of the following? | Pterophytes |
| The development of the __________ prevents plants from drying out and protects them from microbes. | cuticle |
| The "dots" on the underside of a fern frond are spore cases; therefore, what is true of the plant to which the frond belongs? | It is a sporophyte. |
| In what way do megasporangia differ from microsporangia? | Megasporangia produce spores that develop into female gametophytes, whereas microsporangia produce spores that develop into male gametophytes. |
| Evidence suggests that land plants arose from within which protist lineage? | Charophytes |
| To examine meiosis in ferns, you would study __________. | the sporangia |
| A major division in plant systematics is based on whether a particular species has __________. | vascular tissue |
| Typically, the upper part of a bryophyte capsule that contains the spores features a ring of interlocking, tooth-like structures known as the __________. | peristome |
| The embryophytes are __________. | the land plants |
| Which of the following are traits shared by land plants and their closest relatives among the algae? | -Rings of cellulose-synthesizing proteins in the plasma membrane -Structure of flagellated sperm -Formation of a phragmoplast |
| Where would you find a fern gametophyte? | on moist soil |
| What structures allow plants to readily take up carbon dioxide from the atmosphere? | stomata |
| Alternation of generations in all land plants is between __________. | a multicellular haploid organism and a multicellular diploid organism |
| Which of the following is a genus in the phylum Monilophyta? | Equisetum |
| Which is a key difference between alternation of generations in plants and sexual reproduction in nonplant organisms? | In plants, the haploid and diploid stages are both multicellular. |
| In moving to land, plants had to overcome which of the following challenges? | Desiccation |
| Which of the following is true of the life cycle of bryophytes? | A moist environment is required for sexual reproduction. |
| In sporophyte ferns, the leaves are __________. | megaphylls |
| The tissue called phloem has what function in vascular plants? | Distribution of sugars, amino acids, and other organic products |
| What characteristic of Sphagnum peatlands is responsible for their ability to inhibit decomposition? | -Phenolic compounds produced by Sphagnum -Low temperature -Low pH -Low oxygen |
| Which of the following is a trait unique to land plants? | Walled spores produced in sporangia |
| Fern gametophytes are __________. | free-living, multicellular organisms |
| Which of the following statements about algae and plants is true? | Plants have a waxy, waterproof cuticle, and algae do not. |
| The antheridia of mosses produce __________. | sperm |
| How are gametes produced by bryophytes? | By mitosis of gametophyte cells |
| During what period did seedless vascular plants form extensive forests of tall trees? | Carboniferous |
| The gametophyte stage of the plant life cycle is most conspicuous in __________. | mosses |
| What is advantage is conferred to algae and plants that possess sporopollenin? | Reproductive cells are more resistant to desiccation. |
| Water is brought into mosses primarily by __________. | diffusion through all cells |
| What is the evolutionary significance of megaphylls? | They increase the surface area for photosynthesis. |
| The pollen of conifers is primarily dispersed by __________. | wind |
| What significant change occurred on Earth between the Carboniferous period and the Permian period that most likely contributed to the success of the gymnosperms? | The climate became drier and warmer. |
| Which example below is evidence provided by living gymnosperms of an evolutionary transition between seedless and seed plants? | The sperm of some gymnosperms have flagella. |
| The diploid generation of the plant life cycle always __________. | produces spores |
| Of the following, which is a difference in how reproduction occurs in gymnosperms compared to angiosperms? | Only the sperm of angiosperms combine with two central cell nuclei to form triploid endosperm. |
| Which of the following is not an advantage seeds provide over spores? | Asexual reproduction |
| Which of the following is a trait possessed by all angiosperms? | Double fertilization |
| The closest seedless relatives of seed plants produce one kind of spore that gives rise to a bisexual gametophyte. What does this suggest about the ancestors of seed plants? | They were homosporous. |
| In gymnosperms, the seed coat develops from the integument. In angiosperms, the seed coat develops from the __________. | integuments |
| Dietary supplements and decongestants containing ephedrine have recently become more strongly regulated in the United States. Ephedrine is an extract of a plant belonging to which phylum? | Phylum Gnetophyta |
| In which group is the sporophyte stage dominant in the alternation of generations? | all vascular plants |
| The dicots are now thought to be in the paraphyletic group, and the majority of dicot species are now placed in the eudicots. Which of the following is a member of a group that was included in the dicots but is now included in the eudicots? | Southern magnolia |
| Besides the plant tissue that humans ingest, which angiosperm tissue is most directly important for human survival? | xylem |
| Which of the following is enclosed within the pollen wall of a pollen grain? | Male gametophyte |
| Which of the following is not a gymnosperm? | Coconut palm |
| Angiosperms are thought to have originated in which period? | Cretaceous |
| In which phylum is the organism thought to be the world’s oldest living tree? | Coniferophyta |
| The pore in the integuments of an angiosperm ovule through which sperm is delivered is the __________. | micropyle |
| A plant is said to be cross-pollinated if __________. | pollen grains are transferred to a flower on a different plant |
| Six major crops—wheat, rice, maize, potatoes, cassava, and sweet potatoes—constitute what percentage of all the calories consumed by humans? | 80% |
| At current rates of deforestation, tropical rain forests will be eliminated in __________ years. | 200 |
| Which of the following is not a trait characteristic of monocots? | Taproot |
| Which gymnosperm phylum below is characterized by large cones and fern-like leaves and thrived during the Mesozoic? | Cycadophyta |
| In addition to seeds, what is a trait unique to seed plants? | Pollen |
| The seed coat’s most important function is to provide protection for the __________. | sporophyte embryo |
| A bright pink flower with deep floral tubes will most likely be pollinated by which mechanism? | Birds with long beaks |
| A pea pod is formed from __________. A pea inside the pod is formed from __________. | an ovary; an ovule |
| Which of the following is a conifer? | -Common juniper -Longleaf pine -European larch -Sequoia |
| In flowers, pollen is produced in the __________. | anther |
| Which of the following best describes the function of fruits? | Protection and dispersal of seeds |
| Point mutations in noncoding regions of DNA result in __________. | neutral variation |
| Which of the following statements correctly describes a population in Hardy-Weinberg equilibrium? | Allele and genotype frequencies in the population will remain constant from generation to generation. |
| Natural selection leads to adaptation, but there are many organisms on Earth that exhibit characteristics that are less than ideal for their environment. Which of the following statements correctly explain(s) this? | -Selection can act only on existing variations. -Evolution is limited by historical constraints. -Adaptations are often compromises. -Chance, natural selection, and the environment interact. |
| Antibiotic resistance in bacteria is an example of which of the following? | Directional selection |
| In the Hardy-Weinberg equation, q2 represents __________. | the expected frequency of the homozygous recessive genotype |
| In the context of populations, how do we define evolution? | Evolution is a change in a population's allele frequencies over generations. |
| Which of the following would seem to be an example of neutral variation? | Human fingerprints |
| Which of the following sets of conditions is required for Hardy-Weinberg equilibrium? | Random mating, no natural selection, and a large population |
| In a population that is in Hardy-Weinberg equilibrium, 64% of the individuals express the recessive phenotype for a particular gene locus. What is the expected frequency of the dominant allele in this population? | 0.2 |
| In a large population of randomly breeding organisms, the frequency of a recessive allele is initially 0.3. There is no migration and no selection. Humans enter this ecosystem and selectively hunt individuals showing the dominant trait. When the gene freq | the frequency of the homozygous dominants will go down, the frequency of the heterozygous genotype will go down, and the frequency of the homozygous recessives will go up |
| A population of squirrels is preyed on by small hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in the area tend to be very small or very large. What process is | Disruptive selection |
| At what level does gene variability quantify genetic variation? | Whole-gene |
| Which statement below is true about sexual selection? | Sexual selection can result in sexual dimorphism—marked differences between the sexes in secondary sexual characteristics that are not associated directly with reproduction. |
| Which of the following is the best example of gene flow? | Wind blows pollen from one population of plants to another and cross-fertilization occurs. |
| In a population that is in Hardy-Weinberg equilibrium, 64% of the individuals express the recessive phenotype for a particular gene locus. What is the expected frequency of the recessive allele in this population? | 0.8 |
| Sexual recombination includes the shuffling of chromosomes in __________ and fertilization. | meiosis |
| Which of the following can form entirely new alleles? | mutation |
| In a certain group of people, 4% are born with sickle-cell disease (homozygous recessive). If this group is in Hardy-Weinberg equilibrium, what percentage of the group is heterozygous for the sickle hemoglobin allele? | 32% |
| No two people are genetically identical, except for identical twins. The main source of genetic variation among human individuals is __________. | the reshuffling of alleles in sexual reproduction |
| All of the following conditions are required for Hardy-Weinberg equilibrium except __________. | natural selection |
| Which of the following statements correctly describe(s) characteristics of genetic drift? | -It is significant in small populations. -It can cause allele frequencies to change at random. -It can lead to a loss of genetic variation in a population. -It can cause harmful alleles to become fixed in a population. |
| In the Hardy-Weinberg equation, 2pq represents __________. | the expected frequency of the heterozygous genotype |
| Which type of selection maintains stable frequencies of two or more phenotypic forms in a population? | Balancing selection |
| Stabilizing selection __________. | favors intermediate variants in a population |
| A storm separates a small number of birds in a migrating population. These birds end up at a destination different from where they usually migrate and establish a new population in this new area. This is an example of __________. | the founder effect |
| A hurricane hits a small island, killing all but a few members of a bird population. This is an example of __________. | the bottleneck effect |
| The sickle-cell allele, which is recessive, causes anemia but confers resistance to malaria in individuals who possess it. However, homozygous recessive individuals often die from anemia but not from malaria, and homozygous dominant individuals do not hav | the heterozygote advantage |
| The gene pool of a population consists of __________. | all copies of every type of allele at every locus in all members of the population |
| Which type of mutation plays the most important role in increasing the number of genes in the gene pool? | Duplication |
| Which of the following statements explains why male peacocks with brightly colored feathers are more prevalent than those with plain colors? | Female peacocks choose the showiest males as mates, causing this trait to be more prevalent in the population. |
| In the case of the Lake Victoria cichlids, sympatric speciation has been shown to be driven by __________. | sexual selection |
| A horse and a donkey can reproduce successfully, producing a mule. However, the mule is sterile. This is an example of a __________ barrier called __________. | postzygotic; reduced hybrid fertility |
| Two different species of frogs mate successfully and produce fertile hybrid offspring. However, the offspring of the hybrids do not develop completely to adulthood. This is an example of which type of reproductive barrier? | hybrid breakdown |
| According to the punctuated equilibrium model of evolution, __________. | the tempo of evolution consists of abrupt episodes of speciation among long periods of equilibrium |
| Which of the following reproductive barriers actually prevents individuals of closely related species from copulating successfully? | Mechanical isolation |
| Which of the following evolutionary mechanisms does not contribute to the process of allopatric speciation? | gene flow |
| In which of the following groups has sympatric speciation been most important? | plants |
| What is the first thing that must happen in order for speciation to occur? | Gene flow between populations must be interrupted. |
| At which point in the adaptation of a population is it clear that speciation has occurred? | Gene pool changes establish reproductive barriers between two populations. |
| Which of the following statements correctly describes one aspect of the punctuated model of evolution? | Species tend to change rapidly in a short period of time. |
| There are two groups of pine trees that appear to be very similar phenotypically and genotypically. However, one releases pollen in January, when the female structures of that group are receptive, and one in March. What kind of reproductive barrier is th | Temporal isolation |
| A new species of plant evolved by allopolyploidy from two species of plant that are 2n = 6 and 2n = 12. What would the diploid number of chromosomes be in this new species? | 18 |
| When gene flow between two populations ceases, the potential for __________ exists. | speciation |
| The behavior of a male blue-footed boobie during the courtship ritual elicits no response from the masked boobie. The reproductive barrier between them is an example of __________. | behavioral isolation |
| Reproductive isolation is necessary for __________ to occur. | speciation |
| Sympatric speciation typically occurs by all of the following mechanisms except __________. | a geographic barrier splitting a population |
| The evolution of multiple species of snapping shrimp following the formation of the Isthmus of Panama is an example of __________. | allopatric speciation |
| The time interval between speciation events __________. | vary widely and depend on generation times, causes of speciation, environmental factors, and chance |
| Postzygotic barriers __________. | contribute to reproductive isolation after a hybrid zygote has been formed |
| A new species of plant arises as an allopolyploid from two other plants, one with a diploid number of 14 and one with a diploid number of 18. What would the diploid number of the new species most likely be? | 32 |
| The morphological species concept distinguishes species by __________. | body shape and other structural features |
| Three species of sea stars all mate near the same reef by secreting their gametes into the water, but none of the gametes from the different species fertilize each other. This is an example of a __________ barrier called __________. | prezygotic; gametic isolation |
| How many genes must change in order to form a new species? | There is no set number of genes or loci that produces a new species. Genetic and environmental factors interact. |
| A hybrid zone is defined as __________. | a region in which members of different species meet and mate, producing at least some offspring of mixed ancestry |
| Prezygotic barriers __________. | prevent fertilization of gametes from members of closely related species |
| Which of the following is an example of a postzygotic reproductive barrier? | Two fruit flies of different species produce sterile offspring. |
| A new species of plant is discovered that closely resembles a known species. Upon further examination, it is discovered that the new species has a tetraploid number of 4n = 12, while the known species has a diploid number of 2n = 6. Which of the f | An error in cell division occurred in the known species, leading to the development of an autopolyploid tetraploid offspring that evolved into the new species. |
| According to the __________, a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring—but do not produce viable, fertile offspring with members of other such groups. | biological species concept |
| Imagine that part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the re | Individuals from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. |
| Which of the following is the correct order of taxonomic levels in the Linnean system of classification, from most to least inclusive? | Domain, kingdom, phylum, class, order, family, genus, species |
| What is a primary reason why a three-domain taxonomic scheme has been adopted over the previous five-kingdom taxonomic scheme? | Phylogenies based on genetic data revealed that some prokaryotes (kingdom Monera) differ as much from each other as they differ from eukaryotes. |
| The separate lineages leading to dolphins and sharks both evolved streamlined bodies, dorsal fins, and broad tail fins as adaptations to efficient locomotion in a marine environment. In this comparison, the bodies and fins of dolphins and sharks are what | Analogous |
| Birds and mammals have a four-chambered heart, but most reptiles have a three-chambered heart. How does this fact affect the construction of phylogenetic trees for these groups? | The most likely tree is not always the most parsimonious. |
| In cladistics, biologists attempt to place species into groups that each include an ancestral species and all of its descendants. A group that is paraphyletic fails to accomplish this goal in what way? | It consists of an ancestral species and some, but not all, of its descendants. |
| By applying a molecular clock, researchers have proposed that the first HIV-1 M invasion into humans occurred in the __________. | 1930s |
| Which of the following is a true statement concerning horizontal gene transfer? | Horizontal gene transfer is known to occur within both prokaryotes and eukaryotes. |
| Why are phylogenetic trees considered hypotheses? | A phylogenetic tree can be used to make testable predictions. |
| The binomial system assigns to each organism a unique name that describes its __________. | genus and species |
| Rabbits and guinea pigs both belong to class Mammalia. This means they must also both belong to __________. | phylum Chordata |
| A bald eagle and a black bear both have four limbs with digits because they are both tetrapods, descendants of a four-limbed ancestor. In this comparison, the limbs of the eagle and the bear are what type of structure? | Homologous |
| A taxon __________. | is a formal grouping at any given level |
| What is the basis for the use of a molecular clock to determine the absolute time of evolutionary change? | Nucleotide substitutions in a gene occur at a relatively constant rate. |
| Which of the following is an assumption that should be made when reading a phylogenetic tree? | None of the listed assumptions should be made. |
| Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up __________. | a paraphyletic group |
| Sister taxa on a phylogenetic tree are defined as groups that __________. | share an immediate common ancestor and are each other’s closest relatives |
| The principle of maximum parsimony is applied to the process of constructing a phylogenetic tree in what way? | The tree that requires the fewest evolutionary events, as measured by the origin of shared derived characters, is selected. |
| Two genes are recognized as orthologous if __________. | they are homologous genes found in different species, and their divergence traces back to speciation events that produced the species |
| The term polytomy refers to a situation in which __________. | there is a branch point on a phylogeny from which more than two descendent groups emerge |
| Researchers can use molecular homologies to __________. | reveal the number of mutations in a particular sequence that has occurred in each species since they diverged from a common ancestor |
| In a cladistic approach to systematics, an outgroup is __________. | a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes all the species under study |
| Which of the following would be the least useful in determining the relationships among various species? | Analogous structures |
| If you wanted to determine the lineage of plants that have evolved on a relatively young archipelago—approximately 15,000 years old—what type of nucleic acid should you compare? | mtDNA |
| A phylogenetic tree of bird families constructed by cladistic analysis would be a hypothesis about which of the following? | Evolutionary relationships among bird families |
| Looking at the character table and phylogenetic tree above, which of the following is a true statement? | A backbone is a shared ancestral character in mammals (leopard). |
| Which of the following best summarizes the neutral theory? | Darwinian selection does not influence a lot of evolutionary change in genes and proteins because many of these changes do not affect fitness. |
| Using cladistic analysis, a taxonomist wishes to construct a phylogenetic tree showing the relationships among various species of mammals. Which of the following would be the least useful for this purpose? | The fact that all mammals have hair |
| The idea of using molecules as clocks to time evolutionary events is very attractive, but there are many problems in actually applying the technique. What seems to be the best way to get reliable results? | It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out |
| What is the relationship between systematics and taxonomy? | Systematics is a discipline within taxonomy. |
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