Evo exam 4
The famous K-T extinction occurred about 65 million years ago, at the boundary of the Cretaceous and Tertiary periods, with profound effects on many different taxa, including the dinosaurs. Which is the widely accepted as the cause of this extinction? a) This mass extinction occurred gradually over the course of millions of years, likely as a result of gradual changes in temperature, humidity, sea level, and other environmental properties. b) An impact with an extraterrestrial body, such as an asteroid, as evidenced by the layer of clay demarcating the Cretaceous-Tertiary boundary which contains iridium. c) A giant supernova had exploded near Earth and the radiation produced and the climate changes. d) none of the above
An impact with an extraterrestrial body, such as an asteroid, as evidenced by the layer of clay demarcating the Cretaceous-Tertiary boundary which contains iridium.
Look in the three graphs below, showing three different types of evolutionary change in a hypothetical clade. The y-axis represents time, while the x-axis represents a character (body size, in this example). Which of the following graphs represents an active evolutionary trend? a) a b) b c) c d) none of the above
C), c, the one where the red lines shift to the right
Radiocarbon dating (14C) is a useful tool for measuring absolute time for about ________________ years. a) 50,000 b) 500,000 c) 5,000,000 d) 150,000,000
a) 50,000
Lice are often obligate parasites on specific hosts, and because of such close associations; they are often used in studies of species interaction and coevolution. One such example involves lice on pigeons and doves, where phylogenetic studies uncovered eight cospeciation events. What drove their evolution in this host-parasite system? a) After a speciation event occurs in a pigeon or dove, lice are constrained to remain on their host species because they often fare poorly when switching hosts. b) When speciation changes the size of their natural host, lice may opt to living on a new host, which is a different size than their original host. c) Studies proposed that there were benefits to lice if they stayed on size-matched species, with small lice living on the large host species and larger lice on small host species. d) all of the above
a) After a speciation event occurs in a pigeon or dove, lice are constrained to remain on their host species because they often fare poorly when switching hosts. b) When speciation changes the size of their natural host, lice may opt to living on a new host, which is a different size than their original host.
One of the first studied Hox gene mutations in Drosophila was a mutation in the Antennapedia (Ant) gene, which controls leg formation. This mutation is abbreviated as Antp. What is the phenotypic effect of this mutation? a) Antennae are replaced by legs. b) Antennae are replaced by wings. c) Abdominal parts develop in the anterior. d) Four pairs of legs in the thoracic region.
a) Antennae are replaced by legs.
Which of the following is not true regarding the evolution of group living? a) Group living provides many benefits, but it does not improve foraging (finding food). b) Group living includes benefits associated with safety from predators. c) Group living requires new levels of coordination and communication between individuals. d) A group is defined as a set of conspecific individuals that affect each other's fitness.
a) Group living provides many benefits, but it does not improve foraging (finding food)
Which of the following defines Haldane's rule and its predictions? a) If among hybrid offspring one sex is absent, rare, or sterile, that sex is the heterogametic. b) If among hybrid offspring one sex is absent, rare, or sterile, that sex is the male. c) If among hybrid offspring one sex is absent, rare, or sterile, that sex is the female. d) none of the above
a) If among hybrid offspring one sex is absent, rare, or sterile, that sex is the heterogametic.
The origin of cell structures might be hypothesized to have involved a hypercycle, based on mutualism at the molecular level. Which of the following is correct regarding the hypercycle model? a) Natural selection will favor a hypercycle that is enclosed in a membrane. b) Natural selection will favor a hypercycle that is not enclosed in a membrane. c) The molecular mutualisms may have been important among the cells in the DNA world, but not for the replicators in the RNA world. d) None of the above is true for the hypercycle model.
a) Natural selection will favor a hypercycle that is enclosed in a membrane.
In the common bluegill sunfish, foraging in small groups increases success in finding food. They feed on small, aquatic insects that live in underwater vegetation and when bluegills forage together they are able to flush out many more insects. Which of the following is correct in this case of group foraging? a) The bluegill example illustrates a "passive" benefit of group foraging. b) This example illustrates an "active" benefit of group living and communication. c) The bluegill foraging is a product of complex patterns of social rules. d) all of the above
a) The bluegill example illustrates a "passive" benefit of group foraging.
Which of the following statements about the Lincoln and Joyce experiment on self-replicating ribozymes is most likely correct? a) The self-replicating ribozymes that had more efficient catalytic activities would soon began to dominate their populations. b) In the self-replicating ribozymes, variation in the rate of replication was not heritable. c) Ribozymes produced true protein-based enzymes. all of the above
a) The self-replicating ribozymes that had more efficient catalytic activities would soon began to dominate their populations.
In 1997 Lutzoni and Pagel compared the rate of nucleotide substitution in free-living versus mutualistic fungi, in order to test a hypothesis that coevolution could promote the rate of molecular evolution in participating species. Which of the following was not supported by their results? a) There was a more rapid rate of molecular evolution in the free-living fungi (related to the species that lives in lichens), than in the mutualistic species. b) The rates of nucleotide substitution were higher in fungal species involved in mutualistic relationships with algae and liverworts than the rates in the closely related, free-living fungal species. c) The increased rate of nucleotide substitution occurred only during or after the transition to the mutualistic relationship. The increased rate of nucleotide substitution in mutualistic species was widespread across many sections of the genome.
a) There was a more rapid rate of molecular evolution in the free-living fungi (related to the species that lives in lichens), than in the mutualistic species.
The leaf-cutter ant (Acromyrmex octospinosus) is one species of ant that participates in a beneficial mutualism with a fungal species. The female workers in the colony as well as the reproductive females are often covered with a thick whitish-gray coating, which turns out to be a bacterium that produces antibiotics. Which of the following is true regarding the function of these bacteria? a) They produce antibiotics, which kill parasites that grow in the fungal gardens. b) They produce antibiotics, which kill parasites in the ant eggs and larvae. c) none of the above
a) They produce antibiotics, which kill parasites that grow in the fungal gardens.
Fossils are the remains of past-living organisms that could form in several different ways. Which of the following describes fossilization by dissolution? a) Water seeps into fossils and breaks it down, but the shape of the fossil is preserved in the sediment around, leaving an image of the organism. b) Minerals such as calcium and phosphorus, which were once part of a living organism, are slowly replaced through chemical processes by such minerals as iron and silica. c) Organisms fossilize as layers of thin carbon spread on sandstone and shale. d) Organisms are fossilized into a gooey tree resin called amber.
a) Water seeps into fossils and breaks it down, but the shape of the fossil is preserved in the sediment around, leaving an image of the organism.
The famous radiation of Galapagos finches from the common ancestor species on the Western coast of South America is probably a result of: a) allopatric speciation b)parapatric speciation c)sympatric speciation d)none of the above
a) allopatric speciation
In a study of two spruce species, red and black, scientists found that the red spruce was living in a smaller geographic area and had much less genetic variation than the black spruce. They proposed that the red spruce might have arisen from a southern population of black spruce, which became geographically isolated from other black spruce populations at some point during the Pleistocene glaciations. This is an example of: a) allopatric speciation with the peripheral isolate model. b) allopatric speciation with the dumbbell model. c) sympatric speciation. d) all of the above
a) allopatric speciation with the peripheral isolate model.
What type of infectious disease is devastating populations of frogs in North America, Alaska, and Australia today? a) chytridiomycosis, which interferes with the ability of amphibians to transport chemicals across the epidermis b) various bacterial infections that cause sterility in frogs c) an incurable water mold that feeds on the amphibian larvae d) highly contagious viral infections, which are spread by human contamination of the waters
a) chytridiomycosis, which interferes with the ability of amphibians to transport chemicals across the epidermis
In 1977 Sidney Fox tried a different approach to testing the prebiotic synthesis of biological molecules. He mixed a number of different amino acids together at a high temperature (120°C) in an environment lacking water. When he subsequently placed the mixture into water to investigate what the amino acids would form, he: a) found some peptide-like structures, but the bonds between the amino acids were weak and unstable. b) found that a mechanism for joining the amino acids together to make proteins was completely absent. c) found ribose in very low supply d) added CO and had success with creating polypeptides.
a) found some peptide-like structures, but the bonds between the amino acids were weak and unstable.
Jablonski and his coworkers found that, for slugs and snails (gastropods) of the Late Cretaceous period, the key to a broad geographic range at the species level and increased chances of surviving the mass extinction at the K-T boundary was the nature of their larval stage. Which of the following best describes a stage that contributes to the increased geographic ranges of the gastropod taxa? a) planktotrophic larvae that feed in the open water on very small prey and develop into adults at a relatively slow pace. b) any type of larvae that feed in closed water pools and develop into adults at a faster pace. c) nonplankotrophic larvae that feed in closed water pools and develop into adults at a relatively slow pace. d) all of the above
a) planktotrophic larvae that feed in the open water on very small prey and develop into adults at a relatively slow pace.
In 1970, Lynn Margulis proposed that the origin of two eukaryotic organelles, mitochondria and chloroplasts, occurred through endosymbiosis. Which prokaryotic lineage is a phylogenetic candidate as the source of mitochondria? a) proteobacteria b) archaea c) cyanobacteria d) ancient protozoa
a) proteobacteria
Which one of the following is not a major transition in the evolution of life, based on Maynard Smith and Szathmary (1997)? a) the formation of the solar system including Earth b) the origin of self-replicating molecules capable of heredity c) the evolution of sexual reproduction d) the evolution of multicellular organisms from single-celled ancestors
a) the formation of the solar system including Earth
Biologists have documented asexual reproduction in some animal lineages. Even in some vertebrates, such as reptiles, some species reproduce only with parthenogenesis (development from unfertilized eggs). However, parthenogenesis has never been documented in mammals. What is the current genetic explanation for this difference between mammals and other vertebrates? a)Mammals evolved a process of genetic imprinting and therefore some genes from father's genomes need to be expressed. b)Mammals are the only class of vertebrates with evolutionary benefits of recombination. c)The number of offspring produced sexually exceeds the number of offspring in asexual reproduction. d)all of the above
a)Mammals evolved a process of genetic imprinting and therefore some genes from father's genomes need to be expressed.
Which of the following is true for the ancient Greek view of ontogeny (the development of an individual over its lifetime), which was later developed as the concept of "scala naturae" (or the "great chain of being") in the European natural sciences? a)The ancient Greeks argued that the ontogeny of an individual was built up from simple traits in early development to more complex traits later in the developmental process. b)The ancient Greeks did not see a parallel between this scale of nature (which involves the relationships between species) and the developmental stages of organisms. c) Greek philosophers noted that all life, at all scales, is the process that moves from complex to simple. d) all of the above
a)The ancient Greeks argued that the ontogeny of an individual was built up from simple traits in early development to more complex traits later in the developmental process.
If a gene is affected by many regulatory enhancers, what would be an important evolutionary implication? a)The enhancers can increase morphological variation and hence the amount of variation that natural selection has to act on. b)A single gene can have numerous regulatory enhancers associated with it, but these regulators can produce only small variations in gene expression. c) There is no current experimental data that would indicate evolution in the regulatory enhancers. d) The primary control point at which gene expression is regulated is initiation of translation, so transcription enhancers do not play a significant role.
a)The enhancers can increase morphological variation and hence the amount of variation that natural selection has to act on.
Heterochrony is well studied in amphibians. One of the famous examples is in a species of salamanders (Mexican axolotl), where reproductively mature individuals still live in the water and have external gills and flat tails, as in the salamander embryos. This phenomenon is best defined as: a)neoteny. b) progenesis. c) acceleration. d) hypermorphosis.
a)neoteny.
In a hypothetical flowering plant species, one population evolves a different response to the environmental stimuli and began to bloom significantly later in the season than the nearby populations. What type of a reproductive isolating mechanism this would be? a)prezygotic b) postzygotic c) both a and b d) none of the above
a)prezygotic
Among the oldest fossils on Earth are the microfossils from the Agnes gold mine of South Africa, which are __________ years old. a) 4.5 billion b) 3.2 billion c) 3.5 million d) 500,000
b) 3.2 billion
In the cliff swallows it is common to find a blood-sucking parasite, an insect known as the swallow bug. This bug often clings to the feet of birds, can move from swallow to swallow within colonies, and it is responsible for most of the nest failures and juvenile mortality. The following graph shows a correlation between the colony size and the number of bugs per nest. What conclusion(s) can you make, based on this study? a) As colony size of the cliff swallows increases, the number of swallow bugs per nest decreases. b) As group size increases, the cost of parasitism increases. c) Group living for swallows is practically cost free and provides many benefits. d) all of the above
b) As group size increases, the cost of parasitism increases.
What is the most relevant hypothesis for the benefit of making the switch from the RNA- to a DNA-based genetic system during the evolution of life? a) Replication of RNA is too fast to be favored by natural selection. b) DNA is a more stable molecule because deoxyribose is less reactive than is ribose. c) DNA replication systems do not have the "proofreading" capabilities that are usually present in RNA replication. d) all of the above
b) DNA is a more stable molecule because deoxyribose is less reactive than is ribose.
What do we know about horizontal gene transfer (HGT) in the evolution of early life? a) HGT has played a significant role in the evolution of contemporary prokaryotes, but not in the early stages of the evolution of life. b) HGT was probably a powerful force during early cell evolution, leading to complex cellular organisms. c) HGT played a small, insignificant role in the origin of complex cellular organisms. d) HGT never played an important role in evolution of either prokaryotes or eukaryotes.
b) HGT was probably a powerful force during early cell evolution, leading to complex cellular organisms.
What would be an appropriate evolutionary explanation of the fact that the ordering of some homeotic genes (e.g., Hox genes) on vertebrate chromosomes parallels the ordering of homeotic genes on fruit fly chromosomes? a) Homeotic genes show that insects and vertebrates are closer relatives than the traditional classification system indicates. b) Homeotic genes display ancient homologies. c) Homeotic genes of different animal lineages might be ordered in a similar fashion, yet their sequences are completely different. d) The similarity is a coincidence, not documented in other invertebrates and largely a result of random mutations.
b) Homeotic genes display ancient homologies.
In the early 1980s, studies in fruit flies led to discovery of the master-switch genes involved in animal development. Which of these genes are essential for the development of different body segments of fruit flies? a) MAD-box genes b) Hox genes c)segmental genes d) none of the above
b) Hox genes
Which of the following is correct regarding the endemic species as a model for the study of background extinction? a) Extinctions are not very common in endemic species. b) It is much easier to study extinction in endemic species because such local extinction becomes synonymous with global extinction. c) It is much better to focus on species that live everywhere in the world and prevent their extinction. d) There is no difference between global and endemic species when it comes to the study of extinction.
b) It is much easier to study extinction in endemic species because such local extinction becomes synonymous with global extinction.
As opposed to background extinction, a mass extinction typically refers to the loss of many groups of organisms over a broad geographic range. Which of the following mass extinction in Earth's geological history was the most devastating for the marine families? a) Devonian b) Permian c) Triassic d) Cretaceous-Tertiary boundary
b) Permian
Deep homology of homeotic genes is also seen in plants. For example, the MADS-box genes have been used to work out phylogenetic relationships within flowering species of plants. What was also documented in these studies across many plant lineages? a) The MADS-box genes play a role in flower development, but they don't have any effect on nonflowering plant species, such as gymnosperms. b) The MADS-box genes are also instrumental in nonflowering plant species, where they are involved in developmental pathways in leaf and root systems. c)There is almost no similarity among the flowering and nonflowering plants, in the structure of MADS-box genes that are involved in the early developmental pathways. d) none of the above
b) The MADS-box genes are also instrumental in nonflowering plant species, where they are involved in developmental pathways in leaf and root systems.
Over the last few decades, there has been a major decline in amphibian populations worldwide, including the extinction of many amphibian species. Which of the following is not true regarding the amphibian decline? a) The current rate of extinction in amphibians is much higher than typical background extinction rates. b) The extinctions seem to be due to the increased predation of the amphibians around the world. d) One of the major factors driving these extinctions may be infectious disease.
b) The extinctions seem to be due to the increased predation of the amphibians around the world.
Which of the following is true regarding speciation in Rhagoletis pomonella (the apple maggot fly)? a) The forms of apple maggot fly are already true species that do not interbreed if placed in the same host environment. b) The sympatric races of the apple maggot fly are indeed diverging, and potentially on the path to becoming separate species. c) Although the apple tree was introduced in America 400 years ago, the different races of the apple maggot fly have not evolved any adaptations that correspond to the different fruiting times of their hosts. d) all of the above
b) The sympatric races of the apple maggot fly are indeed diverging, and potentially on the path to becoming separate species.
Many species of mammals and birds alike are known to live in close communities, while other species live solitary lives. What do we know about the benefits of sociality? a) The phylogeny of social groups indicates that sociality is often a shared derived trait, which evolves only once or twice in a given lineage. b) There is often a significant positive correlation between group size, such as, for instance, colony size in birds and survival rate of the population. c) In birds that live in large colonies, there is often a significant positive relationship between colony size and the percentage of nests with nonhatched eggs. d) all of the above
b) There is often a significant positive correlation between group size, such as, for instance, colony size in birds and survival rate of the population.
The apicoplast is an organelle found only in species in a phylum called Apicoplasta. This phylum includes a deadly human parasite, Plasmodium falciparum, which is responsible for malaria. Which of the following is not true regarding the apicoplast organelle? a) Apicoplasts are unique organelles with a quadruple membrane. b) There was only one endosymbiosis, which probably involved a large cyanobacteria engulfed by a protozoan cell, and they both developed second membranes for protection. c) The primary endosymbiosis occurred when one prokaryotic host engulfed a cyanobacterium, giving rise to the initial eukaryote, which was subsequently engulfed in a secondary endosymbiosis. d) Apicoplasts in Plasmodium falciparum and related species are involved in the production of at least 500 different gene products.
b) There was only one endosymbiosis, which probably involved a large cyanobacteria engulfed by a protozoan cell, and they both developed second membranes for protection.
Which of the following describes the phenetic species concept? a) This concept describes species as groups of actually or potentially interbreeding populations, with no gene flow between them. b) This concept looks at organisms that are clustered together in a phenotype space and is often used by numerical taxonomists. c) This concept draws species boundaries using shared derived characters that are unique to one monophyletic group and absent from all other populations in the phylogeny. D) all of the above
b) This concept looks at organisms that are clustered together in a phenotype space and is often used by numerical taxonomists.
During the 1990s Knowlton and colleagues studied pairs of sister species of the genus Alpheus (snapping shrimp). In each of these sister species pairs, members of one pair lived on the Caribbean side of the Isthmus of Panama, while members of the other pair lived on the Pacific side. What type of speciation might be responsible for this speciation? a) allopatric speciation with the peripheral isolate model b) allopatric speciation with the dumbbell model c) sympatric speciation d) all of the above
b) allopatric speciation with the dumbbell model
What type of coevolution produces an evolutionary arms race between a predator and its prey or a parasite and its host, which may go on indefinitely, producing a wide array of adaptations? a) mutualistic coevolution b) antagonistic coevolution c) cospeciation d) none of the above
b) antagonistic coevolution
When we say that a cell is totipotent, we refer to a cell that: a) has undergone a specific developmental pathway b) could differentiate into any of the cell types that makes up the adult organism. c)could differentiate into only one type of cells, yet producing a number of different categories (such as different categories of blood cells). d) all of the above
b) could differentiate into any of the cell types that makes up the adult organism.
In a slime mold species, Dictyostelium discoideum, single-celled individuals gather in the migratory slug stage of development, in response to environmental cues. Which molecule is associated with this signaling? a) small RNAs b) cyclic adenosine monophosphate c) steroid hormones d) lactose
b) cyclic adenosine monophosphate
Neural crest cells in vertebrates are cells that are initially positioned near the neural tube during early development and then migrate to new locations. The development and positioning of these cells is controlled by a set of: a) genes of unknown function b) homeotic genes (Hox, Snail, Dlx). c) mitochondrial genes. d) none of the above
b) homeotic genes (Hox, Snail, Dlx).
Which of the following best represents the definition of an individual, as proposed by Michod? a) single cells and cells in the multicellular organisms, because each has a complete set of genes b) integrated and indivisible wholes that can reproduce and pass heritable variations on to their offspring c) groups of organisms of the same species that live in a closed system of mutual dependency d) any level of organization that is subject to natural selection
b) integrated and indivisible wholes that can reproduce and pass heritable variations on to their offspring
Two common species of frogs from the genus Bombina (B. bombina and B. variegata) live in similar latitudes and ecological conditions, but in two different regions, Central and Eastern Europe. In a narrow strip between these regions, scientists observed a third species, which might have been a hybrid between the former diverging populations of the ancestral species. What evolutionary process might be responsible for the speciation in Bombina? a) allopatric speciation b) parapatric speciation c) sympatric speciation. d) none of the above
b) parapatric speciation
In paleobiology one of the main concepts is that fossils found lower down in the sediment at a particular locality are older than those found closer to the surface. This is often called the law of: a) radiometric dating. b) superposition. c) fossilization. d) none of the above
b) superposition.
Young marsupials are born underdeveloped and with a number of adaptations to the life in mother's pouch. One adaption is particularly important for their survival, since it enables the jaw structures to suckling mother's milk at this early stage of development. What changes in the neural crest development are responsible for this? a) The jaw structure in mammals is primarily under the control of neural crest cells, but the analysis of neural crest development in eutherian and marsupial mammals did not show any difference. b)Analysis of marsupial embryos found that neural crest cells begin their migration much earlier in marsupials than in other mammal groups and this promotes early jaw development. c) The jaw structure in mammals is not under the control of neural crest cells, and the differences between the jaw development in eutherian and marsupial embryos are tied to some other developmental genes. d) none of the above
b)Analysis of marsupial embryos found that neural crest cells begin their migration much earlier in marsupials than in other mammal groups and this promotes early jaw development.
The Dobzhansky-Muller model explains hybrid infertility in crosses between two close species (such as the fruit flies D. simulans and D. melanogaster). Which of the following is the best explanation of this model? a) Hybridization between the two sister species is impossible because of the imminent hybrid sterility. b)Epistatic interactions between the alleles of two or more loci, undergoing different evolutionary paths in the two speciating groups, lead to the fitness costs of hybridization. c) Changes in the numbers of chromosomes cause hybrid zygotes to have lower fitness and often makes them infertile. d) Two species develop strong prezygotic mechanisms of reproductive isolation and mating is less likely to proceed.
b)Epistatic interactions between the alleles of two or more loci, undergoing different evolutionary paths in the two speciating groups, lead to the fitness costs of hybridization.
Rivera and Lake's analysis (2004) suggests that ancient eukaryotic cells emerged from the fusion of an archaeal cell (most likely from the phylum Eocyta) and a bacterium. Which of the following is correct regarding this phylogenetic working hypothesis? a)Eukaryotic cells probably evolved when a parasitic species of bacteria residing in some other prokaryotic cell became less harmful. b)Eukaryotic cells probably evolved through endosymbiosis, in which either the archaeal or bacterial cell was engulfed within the other. c) The origin of eukaryotic lineage probably began when an archaeal cell became integrated into a bacterial cell. d) None of the above is a working hypothesis on the origin of eukaryotic cells.
b)Eukaryotic cells probably evolved through endosymbiosis, in which either the archaeal or bacterial cell was engulfed within the other.
Which of the following examples would be the best match for the statement? "Individuals give up the ability to reproduce independently, and they join together to form a larger grouping that shares reproduction." a) Single-stranded RNA with low replication fidelity was replaced as an informational molecule by double-stranded DNA with high replication fidelity. b)Solitary individuals started living together in colonial groups, sometimes even giving up the possibility of independent replication, as we see in many species of social insects. c)Within a single multicellular body, different cells may specialize in generating movement, digesting food, processing information, or other tasks. d) all of the above
b)Solitary individuals started living together in colonial groups, sometimes even giving up the possibility of independent replication, as we see in many species of social insects.
Karl Ernst von Baer (1792-1876), a German naturalist, biologist, and embryologist, rejected both the scala naturae and the Meckel-Serres law. Instead, von Baer's law states that the: a)embryos display characteristics of embryos from species that preceded them on the scala naturae. b)general characteristics of embryos in closely related species develop before specific characteristics, and embryos of higher taxa do not resemble the adult form of ancestral lower-taxa species. c)developmental stages of an organism progress through all the animal species that came before it on the scala naturae. d) embryos of organisms progress through the adult stages of species that preceded them.
b)general characteristics of embryos in closely related species develop before specific characteristics, and embryos of higher taxa do not resemble the adult form of ancestral lower-taxa species.
In some species of fruit flies, males have black spots on the edge of their wings, which they use for visual displays during courtship dances with females, while in other species, these spots are completely absent. A gene called "yellow" plays a role in the development of these visual features in all of the species. The key to the differences in the amount and spatial distribution of the yellow protein is due to? a) Different gene sequences are recognized as the yellow gene in the different fruit fly species. b)he effects of regulatory enhancers on the yellow gene c) The fact that in fruit fly species without spots there is a regulatory enhancer that causes the yellow gene to express the yellow protein at high levels all over the wing. d) all of the above
b)he effects of regulatory enhancers on the yellow gene
Paleontological studies on a lineage of Bryozoan (whose fossils preserve many of their morphological characteristics) show a pattern of evolution with little or no change for long stretches of time. Occasionally however, speciation occurred in a burst of change and diversification. This is an example of: a) phyletic gradualism. b)punctuated equilibrium. c) slow evolutionary change. d) all of the above
b)punctuated equilibrium.
Thyroid hormone (TH) has been identified as one of the factors promoting phenotype development in the Mexican salamander, or axolotl. All of the following statements regarding the impact of TH are true except: a) Axolotls maturing in water with high concentration of T4 metamorphose into a terrestrial form. b) Most salamander species produce a burst of TH when they move from the water to the land. c) Adding thyroid hormone (T4) to the water in which axolotl individuals were reared causes them to remain in a larval stage. d) A genome-wide scan of both the axolotl and its sister species found a large reduction in the number of mRNA genes that regulate the production of TH.
c) Adding thyroid hormone (T4) to the water in which axolotl individuals were reared causes them to remain in a larval stage.
The human parasite Mycoplasma genitalium, withone of the smallest genomes of any organism that can be grown, as well as Chlamydia trachomatis, an obligate intracellular parasite, are examples of the types of organisms that functional genomics researchers have focused on. What is the main purpose of the study of such genomes? a) These and other obligate parasites or symbiontes are very easy to study. b) They are very ancient prokaryotes with original small genomes. c) By studying such genomes, researchers try to discover the basic and essential cellular functions of early life. d) all of the above
c) By studying such genomes, researchers try to discover the basic and essential cellular functions of early life.
In light of recent achievements in the field of genomics, would it be reasonable to expect that the use of comparative genomics might shed light on the extinct genomes of early life? a) Simple prokaryotes today have very different genomes than early life and we could not learn very much from the comparative genomics of the extant species. b) Despite efforts in molecular prokaryotic genetics, we cannot predict what kinds of genes may have been present in pre-LUCA genomes. c) Comparative genomics and studies of the bacteria with very small genomes do shed light on a common ancestor and researchers can estimate the minimal characteristics that a cell would need to operate as a living organism. d) none of the above
c) Comparative genomics and studies of the bacteria with very small genomes do shed light on a common ancestor and researchers can estimate the minimal characteristics that a cell would need to operate as a living organism.
Based on the abundant fossil records, only 10,000 years ago, two-thirds of the 150 genera of the Pleistocene megafauna that were present 40,000 years earlier had gone extinct. What seems to be the reason for this relatively recent extinction of so many large mammal species? a) This extinction was probably due to new pathogens. b) Global warming seems to be a contributing factor in the loss of these large mammal species. c) Hunting by humans, habitat fragmentation, and the ice age played a large role in this extinction. d) all of the above
c) Hunting by humans, habitat fragmentation, and the ice age played a large role in this extinction
Which of the following statements about LUCA is not correct? a) The acronym stands for "last universal common ancestor." b) It represents a base to the tree of life. c) It is meant to be a single organism. d) It represents a phylogenetic event horizon.
c) It is meant to be a single organism.
What is the meaning of the phrase "dead clade walking," which was coined by Jablonski in 2002? a) Following the mass extinctions, such as in the Permian, there is nothing to be found in many strata. b) The new clades, which emerge following the mass extinction, quickly die out due to the lack of nutrients and other resources. c) Many of the remaining clades that survived a period of mass extinction go extinct during the following geological time period. d) both a and b
c) Many of the remaining clades that survived a period of mass extinction go extinct during the following geological time period.
Which of the following statements regarding the complexity of living organisms is not correct? a) The body size of the largest living organisms has increased over evolutionary time. b) The complexity of multicellular organisms, as measured by the number of cell types, has increased over evolutionary time. c) Natural selection necessarily entails an increase of complexity over evolutionary time. d) Modern bacteria and archaea are not more complex than their ancestors that lived before the origin of multicellular life.
c) Natural selection necessarily entails an increase of complexity over evolutionary time.
Which two scientists elaborated on Darwin's idea of the "warm little pond" and formulated the "prebiotic soup hypothesis" as the first hypothesis for the abiotic origin of life on earth? a) Miller and Urey b) Cech and Altman c) Oparin and Haldene d) none of the above
c) Oparin and Haldene
The first genetic material was most likely: a) DNA b) a small protein c) RNA d) a large lipid
c) RNA
Slime molds are unusual eukaryotes. They spend most of their life cycle as single-celled organisms and yet, under certain conditions, they form a slug-like multicellular stage and then a fruiting body composed of both somatic cells and reproductive spores. The best known species of slime mold is a soil dweller, Dictyostelium discoideum. Why is it important to study this and related species of slime molds? a) Slime molds first appeared about 1 billion years ago. b) Dictyostelium discoideum is an important human pathogen. c) Slime molds provide hints as to how multicellularity may have evolved. d) none of the above
c) Slime molds provide hints as to how multicellularity may have evolved.
Soybean legumes are involved in a mutualistic relationship with rhizobial bacteria (B. japonicum) in which bacteria converts inorganic nitrogen in the root nodules of the plant into an organic form of nitrogen that the plant uses as a resource for its own growth and synthesis. In experiments with a nitrogen-free atmosphere, bacteria are forced to be "the cheaters." Which of the following was not found in these experiments? a) Populations of rhizobial bacteria grew larger in plant nodules when nitrogen was present in the atmosphere, versus in a treatment in which the atmosphere was nitrogen-free. b) Soybean plants changed the permeability of the nodule membranes, curtailing the oxygen available to bacteria, which in turn reduced B. japonicum's growth rate. c) Soybean plants did not have an ability to respond to reduced nitrogen fixation by B. japonicum in a way that would reduce cheating. d) Rhizobial bacteria can survive without fixing nitrogen, but the lack of organic nitrogen creates a cost for the plant.
c) Soybean plants did not have an ability to respond to reduced nitrogen fixation by B. japonicum in a way that would reduce cheating.11
Define a regulatory enhancer of a gene. a) The state of chromatin in the surrounding areas is the main enhancer of a gene. b) Enhancers target proteins for degradation and thus stop the expression of the unwanted genes. c) The regulatory enhancer is a section of DNA that lies outside of that gene but is involved in regulating the timing and level of that gene's expression. d) none of the above
c) The regulatory enhancer is a section of DNA that lies outside of that gene but is involved in regulating the timing and level of that gene's expression.
Miller and Urey developed and conducted some experimental tests for a "prebiotic soup" model of the origin of life, which had been proposed a few decades earlier by Oparin and Haldane. What did Miller and Urey show could be synthesized abiotically? a) single-stranded RNA molecules b) liposomes c) amino acids d) ribosomes
c) amino acids
In all of the extinctions that have ever occurred on Earth, the majority of the lost species was due to: a) mass extinctions. b) periodic extinctions. c) background extinctions. d) none of the above
c) background extinctions.
In some species of animals that are preyed upon, we can find evidence of mimicry or false visual signals to their predators suggesting that the prey is most likely unpalatable. One example is a species of Ensatina salamanders that mimics a sympatric species of toxic newts (Taricha torosa). What type of mimicry is this? a) aposematic mimicry b) Müllerian mimicry c) Batesian mimicry d) none of the above
c) bayesian mimicry
Kellogg (1896) and Fahrenholz (1909) both hypothesized that phylogenies of parasites and hosts often change in parallel. Why do we expect that? a) When populations of a host species become geographically isolated from one another, the parasite populations that the host carries also become geographically isolated. b) if divergence in the host species is great enough and host speciation occurs, this can lead to speciation in the parasite as well c) both a and b d) none of the over
c) both a and b
One of the gene duplications in developmental genes in plants, OEP16 is also known to arise along with neofunctionalization. Which of the following statements is true regarding these genes? a) The duplication in OEP16 gene took place in the lineage that led to the land plants. b) The neofunctionalization of the OEP gene may have been partly responsible for the explosion of plant diversity and the evolution of flowering land plants. c) both a and b d) none of the above
c) both a and b
Predator-prey interactions are one type of antagonistic coevolution. Which of the following traits would natural selection favor, in these interactions? a) Selection will favor traits in prey that increase the chance of escaping predation and traits in predators that increase their chance to capture and kill the prey. b) Selection on both participants will lead to an evolutionary arms race in which both predator and prey may evolve new traits. c) both a and b d) none of the above
c) both a and b
The Hawaiian Islands have gone through at least two waves of human colonization (in prehistoric times and again starting in the seventeenth and eighteenth centuries). Of the approximately 125 to 145 bird species that once inhabited the Hawaiian Islands before human colonization, 90 to 110 are now extinct. Which of the following is most likely true when it comes to these extinctions? a) Early human colonization devastated the larger species of birds through hunting. b) Late human colonization devastated the natural habitats and food sources, such as flower nectar and fruit of the native species. c) both a and b d) There is no known cause for these extinctions.
c) both a and b
One of the main features of a eukaryotic cell is the nucleus. Recent evidence suggests that the cell nucleus may have evolved from archaeal ancestors and that the organelles may have evolved from bacterial ancestors, but there is another important factor that shaped the evolution of nuclear genomes. Which of the following is a source of the eukaryotic nuclear genes? a) mitochondria b) chloroplasts c) both mitochondria and chloroplasts d) "promiscuous" genes from nonrelated species of eukaryotes
c) both mitochondria and chloroplasts
Which of the following cases is an example of cospeciation? a) In molecular phylogenetic analysis of nuclear ribosomal DNA of Glochidion trees and Epicephala moths, speciation patterns appear to be very similar. In addition, each species cannot survive in the absence of the other. b) In comparing the phylogenies of lice and their hosts, there is an evidence of congruence between the hosts' and parasites' shared evolutionary history. c) both of the above
c) both of the above
Look at this definition of species: "A species is a lineage of . . . populations which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate." This definition best represents the: a) biological species concept b) ecological species concept c) evolutionary species concept d) phenetic species concept
c) evolutionary species concept
In the late 1800s William Bateson documented, both in insects and in vertebrates, many cases where one body part had replaced another, producing unusual forms. Bateson believed that his studies could teach us something about evolutionary changes. He named these changes: a)developmental mutants b) developmental transformations. c) homeotic transformations. d) homeobox mutants.
c) homeotic transformations.
There are thousands of different kinds of lichens, each of which is composed of one fungal species and one species of either photosynthetic algae or cyanobacteria. When species interact, as fungi and algae do in lichen, so that the interaction of the two species increases the fitness of both species, this is called: a) parasitism b) antagonism c) mutualism d) none of the above
c) mutualism`
Douc langurs are primates that have a diet of leaves instead of insects and fruit. In order to digest such food, these langurs use symbiotic bacteria in their gut and digest some of them using an enzyme associated with a gene known as RNASE. Gene duplication and the subsequent divergence of this gene, seems to be the genetic basis for its evolution. We could say that this is an example of: a) increasing production of ribosomal RNA and histones. b)subfunctionalization. c) neofunctionalization. d) all of the above
c) neofunctionalization.
All of the following is true regarding Spiegelman's experiment on the origins of life except that: a) the most common size of the RNA strand in the final test tubes was a little over 200 nucleotides long. b) variation in the length of strands occurred at each round of replication. c) there was no selection for any of the variations in length. d) shorter RNA sequences were favored by selection, so long as they were not too short.
c) there was no selection for any of the variations in length.
Define homeotic genes. a)Homeotic genes encode proteins that control cellular environment in a differentiated cell tissue. b)Homeotic genes are DNA sequences that turn off, but not on, the expression of other genes and are controlled by "master-switch" genes. c)Homeotic genes are "master-switch" genes that control other genes in a set sequence and thereby affect cell size, shape, division, and the positioning of the cells within the organism. d) all of the above
c)Homeotic genes are "master-switch" genes that control other genes in a set sequence and thereby affect cell size, shape, division, and the positioning of the cells within the organism.
Ernst Haeckel (1834-1919), a German biologist and naturalist, disagreed with von Baer and further expanded on the Meckel-Serres law with his biogenetic law. What does the biogenic law claim? a)The evolutionarily novel traits tend to appear late in development and are good diagnostics for separating closely related species. b) The traits that appear early on in development are extremely resistant to evolutionary change, and hence they are very similar across many taxa. c)The developmental progress of an organism (its ontogeny) recapitulates its evolutionary history (its phylogeny). d) all of the above
c)The developmental progress of an organism (its ontogeny) recapitulates its evolutionary history (its phylogeny).
When a reproductive trait appears earlier in development or when some somatic traits of an adult are retarded, we could define this type of development as: a) recapitulation. b) acceleration c)paedomorphosis. d) hypermorphosis.
c)paedomorphosis.
Which of the following is not true regarding the evolution of multicellularity? a) The evolution of multicellularity represents one of the major transitions in the history of life on Earth. b) The transition has occurred independently many times, in many taxa, over evolutionary history. c) In the early steps toward an obligate multicellularity, cells may have often joined together temporarily and then disbanded. d) The transition from unicellular to multicellular life occurred only once in evolutionary history, giving rise to all multicellular organisms today.
d) The transition from unicellular to multicellular life occurred only once in evolutionary history, giving rise to all multicellular organisms today.
Why did the human introduction of feral pigs on Santa Cruz Island accelerate the extinction of the native fox and increase the population of skunks? a) Increased pig numbers attracted the golden eagle, which is a fierce predator of foxes. b) Skunks were the main prey of the island foxes. c) Pigs were the main prey of the island foxes. d) a and b only
d) a and b only
In order to understand the origin of life on Earth, evolutionary biologists collaborate with: a) chemists. b) geologists. c) atmospheric scientists. d) all of the above
d) all of the above
In the case of California salamanders we can see how traits in one species (coloration of the toxic newts) influence the operation of selection on another (coloration of a nontoxic salamander). The following figure describes the actions of a predator, the western scrub-jay, that was provided with the opportunity to feed on live salamanders. Notice that Ensatina eschscholtzii oregonensis is a nontoxic and plain colored subspecies, a close relative of the mimic Ensatina eschscholtzii xanthoptica. Which of the following is true? a) Jays were very hesitant to approach E. e. xanthoptica, even though this salamander did not possess the neurotoxin found in the newts. b) After their first experience with the toxic California newts, the jays took more time to approach E. e. xanthoptica than E. e. oregonensis individuals. c) If such an encounter happens in the wild, the amount of time the scrub-jay hesitates could make the difference between survival and death for the E. e. xanthoptica. d) all f the above
d) all of the above
It is very difficult to find the fossil remains of the entire organism. Which of the following might be a factor for paleontologists to use when choosing sites to search for the best fossils? a) Paleontologists will typically focus on the sites that best match the geological and abiotic conditions in which fossilization may have occurred. b) Paleontologists are unlikely to be the first researcher to be searching for fossils from their organism of interest. Instead, they often choose sites where others have already uncovered related fossils. c) Paleontologists often use predictions derived from phylogenetic reconstruction, biogeography, or molecular genetics to explore a particular area. d) all of the above
d) all of the above
Which of the following are/is considered a type of heterochrony (changes in the rate and timing of development)? a) hypermorphosis b) acceleration c) neoteny d) all of the above
d) all of the above
Which of the following is true regarding the evolution of chloroplasts? a) Chloroplasts are derived from once free-living photosynthetic cyanobacteria. b) Cyanobacteria are related to algal plastids. c) RNA shows that the chloroplasts of plants are closely related to cyanobacteria. d) all of the above
d) all of the above
Which of the following statements is true about Hox genes experiments? a) Homeobox regions of the Hox genes allow one species' transcription factor to function in the other species. b) When the mouse Hox-2.2 gene is experimentally inserted into the fruit fly genome and expressed in the head of developing fruit flies, adults produce legs in place of antennae. c) When a Hox gene product from an appropriate chromosomal region in chickens was inserted into a fruit fly embryo, it resulted in normal regulation of the fruit fly development. d) all of the above
d) all of the above
In a hypothetical scenario, imagine that you have discovered a rare species of birds on a remote Pacific island. You spend some time studying their ecology and habitation and discover that although these birds look alike, there are indeed two distinct populations with very different mating calls. You propose that these two populations must be two species, since they no longer mate with one another. Which of the following species concepts would you use to defend your statement? a) phylogenetic species concept b) ecological species concept c) phenetic species concept d) biological species concept
d) biological species concept
Evolutionary biologists are very interested in understanding the patterns and processes that guide the tempo and mode of evolution. In specific clades they are studying they sometimes point to trends (patterns of directional change over time). One such trend is also known as Cope's rule. Which of the following statements are true? a) Cope's rule states that species in mammalian clades tend to increase in body size over evolutionary time. b) Avian taxa appeared to follow Cope's rule throughout the Jurassic and Cretaceous periods. c) Cope's rule is universal. d) both a and b
d) both a and b
The imperial blue butterfly (Jalmenus evagoras) and species of ant (Iridomyrmex anceps) have a mutualistic relationship in which the butterfly larvae and pupae secrete sugary nectar that nourishes the ants, while the ants protect the larvae and pupae from predators such as wasps. Which of the following statements describes the investment by both parties? a) This ant-butterfly mutualism involves a significant cost for the imperial blue butterfly. The larvae spend their resources on production of nectar, which leads to slower development and lower reproductive success. b)Ants involved in a mutualistic relationship with butterflies likely have an increased risk of detection by their own predators, as well as metabolic costs associated with defense of the butterfly larvae. c) This mutualistic relationship between the butterfly and ant is not costly for either participant. d) both a and b
d) both a and b
Two parapatric subspecies of sagebrush (mountain big sagebrush and basin big sagebrush) produce hybrid sagebrush, which is often found in the intermediate elevation. In the following graph below, you can see germination early survival rates for each of them raised in three different environments (1,800 meters, above 1,900 meters, and in the hybrid zone between). Which of the following best explains the findings in this experiment? a) The hybrid individuals had lower fitness in environments below 1,800 m and above 1,900 m, but a higher fitness than either subspecies when all types were raised in the hybrid zone. b) These results provide support for the bounded hybrid superiority model. c) These results provide support for the ecologically neutral dynamic equilibrium model. d) both a and b
d) both a and b
Which of the following molecules involved in membrane structure was likely favored by selection in the evolution of early cells? a) nucleic acids b) polypeptides c) steroid hormones d) fatty acids
d) fatty acids
Which gas was most likely the least abundant in early Earth's atmosphere? a) hydrogen b) water c) methane d) oxygen
d) oxygen
A number of evolutionary studies show a strong phylogenetic link between prokaryotic and eukaryotic cells. Which of the following is the best statement about the evolutionary origins of eukaryotic cells? a)Eukaryotes probably evolved from a lost prokaryotic lineage, which could not be placed among either the Archaea or Bacteria domains. b) Eukaryotes shared a common ancestor with species in the domain Archaea. c) Eukaryotes shared a common ancestor with species in the domain Bacteria d)Eukaryotic "informational" genes are closely related to Archaea, while their "operational" genes are closely related to Bacteria.
d)Eukaryotic "informational" genes are closely related to Archaea, while their "operational" genes are closely related to Bacteria.
Which of the following findings regarding the Midas and arrow cichlids in Lake Apoyo suggests that the speciation event responsible for forming these two species occurred in sympatry rather than allopatry? a) The Midas and arrow cichlids are a monophyletic clade. b) Lake Apoyo is small, shallow, and homogeneous. c) Not even one mitochondrial haplotype was found in any other Nicaraguan lake that was the same as those found in the two Lake Apoyo species. d)all of the above
d)all of the above
