Biology 1002 midterm
The emergence of many diverse species from a common ancestor is called A) adaptive radiation. B) gradualism. C) allopatric speciation. D) hybridization.
A) adaptive radiation.
If all of Earths history were compressed into an hour, humans would first appear less than A) 1 second ago. B) 10 seconds ago. C) 1 minute ago. D) 10 minutes ago.
A) 1 second ago.
Miller was the first to show that A) amino acids and other organic molecules could have formed under conditions thought to resemble those of early Earth. B) the earliest forms of life were photosynthetic. C) eukaryotic life evolved from early prokaryotes. D) the earliest forms of life had an RNA genome.
A) amino acids and other organic molecules could have formed under conditions thought to resemble those of early Earth.
Which of the following descriptions best represents the gradual model of speciation? A) Speciation occurs regularly as a result of the accumulation of many small changes. B) An isolated population differentiates quickly from its parent stock as it adapts to its local environment. C) Speciation occurs under unusual circumstances and therefore transitional fossils are hard to find. D) Species undergo little change over long periods interrupted only by short periods of rapid change.
A) Speciation occurs regularly as a result of the accumulation of many small changes.
Scientists evaluating the Cretaceous mass extinction have concluded that A) an asteroid impact was probably the triggering event for the extinction. B) only an extraterrestrial impact could have caused such a big extinction event. C) climate change would not have been involved in producing the extinctions. D) ecological factors such as disease and competition probably caused the dinosaurs to go extinct.
A) an asteroid impact was probably the triggering event for the extinction.
How can the success of one group of organisms promote the adaptive radiation of a second group? A) by providing new food resources, habitats, etc. for the second group B) by competing with the second group, promoting its adaptive radiation C) by preying on the second group, which hastens its adaptation D) by filling most of the available niches, which forces the second group to evolve greater diversity
A) by providing new food resources, habitats, etc. for the second group
Earths continents and seafloors together form a thin outer layer of the planet called the A) crust. B) strata. C) biosphere. D) Pangean supercontinent.
A) crust.
A new plant species may arise in a single generation by A) errors in meiosis leading to polyploidy. B) a sudden geological disruption causing separation of two populations. C) mutations in genes for flower color. D) changes in the pollinator species.
A) errors in meiosis leading to polyploidy.
Speciation often occurs when a habitat becomes more heterogeneous. In Lake Victoria different species of cichlids are found in different areas of the lake. The best explanation for this speciation is that A) natural selection favored different heritable variations in different parts of the lake. B) male cichlids that lived in deep water needed to be seen by females, so they became colorful. C) food was scarce in the lake, so some fish had to learn how to scrape algae, some had to learn to eat insects, and some had to learn to bite leaves. D) humans selected for many different traits in cichlids in order to market them to the aquarium trade.
A) natural selection favored different heritable variations in different parts of the lake.
Diane Dodd raised different fruit fly populations on different food sources. She found that after about 40 generations the evolution of reproductive isolation was under way. The mechanism of evolution responsible for this was A) natural selection. B) genetic drift. C) gene flow. D) mutation.
A) natural selection.
Sympatric speciation commonly occurs through ________ in plants but is more likely to occur through ________ in animals. A) polyploidy; habitat differentiation and sexual selection B) habitat differentiation and sexual selection; polyploidy C) asexual reproduction; chromosome duplications D) self-pollination; polyploidy and other genetic mechanisms
A) polyploidy; habitat differentiation and sexual selection
For speciation to occur there must be A) sexual reproduction. B) genetic variation. C) isolation. D) natural selection.
A) sexual reproduction.
Speciation without geographic isolation is called ________ speciation. A) sympatric B) allopatric C) incomplete D) diversifying
A) sympatric
Which of the following describes the type of speciation event that is occurring in these whales? A) sympatric speciation B) allopatric speciation C) geographic speciation D) polyploid speciation
A) sympatric speciation
In a population of plants with a diploid number of 12, a new individual appeared with a chromosome number of 24. If this organism could self-fertilize, forming offspring with the same number of chromosomes (24), scientists would consider this an example of A) sympatric speciation. B) behavioral isolation. C) formation of a hybrid zone. D) reduced hybrid fertility.
A) sympatric speciation.
Which of the following types of reproductive barriers separates a pair of species that could interbreed but for the fact that one mates at dusk and the other at dawn? A) temporal isolation B) habitat isolation C) behavioral isolation D) mechanical isolation
A) temporal isolation
The Himalayas are an example of a mountain range that formed as a result of A) the collision of two continental plates. B) the separation of two continental plates. C) the buildup of sediments and conversion to rock. D) volcanic eruptions.
A) the collision of two continental plates.
One of the finest available sequences of fossils shows how horses have changed slowly and by subtle steps from small shrub-browsing ancestors to the large, grass-grazing modern horse. A large number of fossil species have been named, and it is often difficult to decide on the identity of a fossil horse because transitional forms are common. This record of evolution best fits the idea of A) the gradual model of speciation. B) punctuated equilibrium. C) adaptive radiation. D) hybrid breakdown.
A) the gradual model of speciation.
The technique called radiometric dating is based on A) the steady, clocklike decay of certain radioactive isotopes over time. B) the assumption that radioactive isotopes accumulate in fossils at a constant rate. C) the formation of radioactive molecules in rocks after they are laid down. D) the use of fossils of known age to determine how fast carbon-14 decays.
A) the steady, clocklike decay of certain radioactive isotopes over time.
Allopatric speciation is not likely to occur when A) there is no disruption in gene flow between two populations. B) a geographic barrier forms between two populations. C) several populations become isolated from one another as drying conditions cause a large body of water to become separate smaller bodies of water. D) separated populations adapt to different environmental conditions.
A) there is no disruption in gene flow between two populations.
Which of the following would tend to promote adaptive radiation? A) An organism has a very stable set of features and capabilities over long spans of evolutionary time. B) An organism colonizes an isolated area that is habitable but relatively devoid of life. C) An organism colonizes an area that already has a high level of existing species diversity. D) A single species goes extinct, but it has several competitors that quickly expand to assume its ecological roles.
B) An organism colonizes an isolated area that is habitable but relatively devoid of life.
The emergence of a new plant species over a brief period of time followed by a long period of little change is consistent with which of the following theories? A) the gradual model of speciation B) allopatric speciation C) punctuated equilibrium D) adaptive radiation
C) punctuated equilibrium
The "big bang" that produced the universe is thought to have occurred A) 40 to 50 billion years ago. B) 12 to 14 billion years ago. C) 4.6 billion years ago. D) 4 million years ago.
B) 12 to 14 billion years ago.
Which of the following statements about plant speciation and hybridization is false? A) Plant biologists estimate that 80% of all living plant species are descended from ancestors that formed by polyploid speciation. B) Bread wheat is the ancestral diploid wheat plant. C) Modern plant geneticists use chemicals to induce meiotic and mitotic errors to try to create new hybrid plants with special qualities. D) Bread wheat grown widely today is the result of several hybridization events.
B) Bread wheat is the ancestral diploid wheat plant.
Over a span of several thousand years, a number of species show adaptations to climate change: Drier, warmer conditions select for succulent vegetation and deep taproots in plants, burrowing in mammals and amphibians, and other similar adaptive changes. What will happen if the climate shifts in the opposite direction and becomes progressively wetter and cooler? A) Ongoing processes of adaptation will continue because of evolutionary inertia. B) Different adaptive trends will probably be favored in the new climatic environment. C) Current adaptive trends will continue, but organisms will now also have to add on adaptations to deal with cool, wet conditions. D) Adaptation will cease because cool, wet conditions are generally favorable for life.
B) Different adaptive trends will probably be favored in the new climatic environment.
Which of the following statements about the Galápagos finches is false? A) The Galápagos finch species differ in their feeding habitats. B) Each island in the Galápagos chain has one and only one isolated, unique species of Darwins finch. C) Most speciation events of the Galápagos finches occurred when some finches made it to another island, evolved in isolation, and accumulated enough changes to become a new species. D) The evolution of the Galápagos finches is an excellent example of adaptive radiation.
B) Each island in the Galápagos chain has one and only one isolated, unique species of Darwins finch.
Geologists have evidence that over the past 1.5 billion years, A) Earths continents have remained essentially in their current shape and positions. B) Earths landmasses have joined into a single continent and split back apart again on three occasions. C) Earths landmasses have moved about extensively but have remained separate. D) Earths landmasses have been entirely submerged in water on three occasions.
B) Earths landmasses have joined into a single continent and split back apart again on three occasions.
Two bird species overlap in a hybrid zone. They are isolated by a slight difference in the male songs and by the females; tendency to select males with the "correct"; song. Hybrid offspring tend to have reduced fertility compared to either of the parent species. What effect might natural selection have in this situation? A) Natural selection might favor males with less distinctive calls and/or females that are less "choosy" B) Natural selection might favor males with more distinctive calls and/or females that are more choosy. As a result, the reproductive barrier between the two species could be reinforced. C) Natural selection could lead to the hybrid species taking over and eliminating the weaker parent species. D) Natural selection could lead to the stronger of the two species taking over and eliminating the other species.
B) Natural selection might favor males with more distinctive calls and/or females that are more choosy. As a result, the reproductive barrier between the two species could be reinforced.
The earliest known land plants date to the A) Precambrian. B) Ordovician (early Paleozoic era). C) Carboniferous (late Paleozoic era). D) Jurassic (Mesozoic era).
B) Ordovician (early Paleozoic era).
At the end of the ________, over 96% of marine species and many terrestrial species became extinct, possibly because intense volcanic activity warmed Earth's climate. A) Precambrian B) Permian C) Cretaceous D) Mesozoic
B) Permian
How is the merging of continents to form Pangaea believed to have altered Earths environments at the end of the Paleozoic era? A) It eliminated all multicellular eukaryotes, allowing evolution to start anew. B) Shallow coastal areas were drained, leading to the extinction of many marine species. C) It made the climate warmer and moister for terrestrial organisms in the center of the new landmass. D) It prompted an immediate increase in Earths biodiversity.
B) Shallow coastal areas were drained, leading to the extinction of many marine species.
Anti-evolutionary thinkers sometimes argue that natural selection could not produce a complex structure like the vertebrate eye. They claim that all of the parts of the eye must have arisen at once, asking why natural selection would favor the development of part of an eye that is not yet capable of forming a focused image. Which of the following statements is consistent witha survey of eye structure in the molluscs? A) The argument has a great deal of merit. Only full-blown image-forming eyes are present in modern organisms. B) There are many intermediate stages of eye complexity that fulfill different adaptive functions. C) The vertebrate eye is the ancestral form, and other types of organisms have degenerate eyes that have lost most of their original structure and function. D) The vertebrate eye works in a way that is completely different from the eyes found in molluscs and other invertebrates.
B) There are many intermediate stages of eye complexity that fulfill different adaptive functions.
In 2004, scientists announced the discovery of the fossil remains of some extremely short early humans on the Indonesian island of Flores. The new species has been named Homo floresiensis. One hypothesis is that H. floresiensis evolved from Homo erectus, another early human species. How did a population of H. erectus become isolated on this remote island? Early humans constructed boats and rafts, so perhaps they were blown far off course by strong winds during a storm. H. erectus averaged almost 6 feet in height, but the remains show that adults of H. floresiensis were only about 3 feet tall. It is hypothesized that limited resources on this hot and humid island (only 31 square miles) exerted selection pressure, and succeeding generations began to shrink in size. Small bodies require less food, use less energy, and are easier to cool than larger bodies. Evolution of small size in similar circumstances has been observed in many other species, but never before in humans. This find demonstrates that evolutionary forces operate on humans in the same way as on all other organisms. 1) The evolution of H. floresiensis is an example of A) sympatric speciation. B) allopatric speciation. C) adaptive radiation. D) hybridization.
B) allopatric speciation.
Uplift and formation of a mountain range divide a freshwater snail species into two isolated populations. Erosion eventually lowers the mountain range and brings the two populations together again, but when they mate, the resulting hybrids all produce sterile young. This scenario is an example of A) sympatric speciation. B) allopatric speciation. C) incomplete speciation. D) diversifying speciation.
B) allopatric speciation.
You find the frozen remains of a woolly mammoth in an Alaskan glacier. You analyze a bit of the tusk and find that its 14C:12C ratio is about one-fourth (25%) of the baseline level typically found in living organisms. Given that the half-life of 14C is 5,730 years, when did the mammoth die? A) 5,730 years ago B) almost 12,000 years ago C) at least 25,000 years ago D) approximately 75,000 years ago
B) almost 12,000 years ago
10) Which of the following types of reproductive barriers separates a pair of moth species that could interbreed but for the fact that the females; mating pheromones are not attractive to the males of the other species? A) temporal isolation B) behavioral isolation C) mechanical isolation D) gametic isolation
B) behavioral isolation
Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________ ________ reproductive barrier. A) mechanical; postzygotic B) behavioral; prezygotic C) temporal; prezygotic D) gametic; postzygotic
B) behavioral; prezygotic
The example of ocean and lake stickleback fishes indicates that morphology can be altered A) only by changing the sequences of protein-coding genes. B) by altering the expression of a developmental gene in some parts of the body but not others. C) by environmental factors (in this case, pollution). D) by the elimination of a gene (Pitx1) from a population, which leads to loss of the trait (body armor and spines).
B) by altering the expression of a developmental gene in some parts of the body but not others.
Miller-type experiments have shown that A) simple cells could be produced in the laboratory using a "soup&"; of small organic molecules. B) complex organic molecules can be produced by physical processes from inorganic components. C) living cells could survive in primitive Earths atmosphere. D) given the conditions of early Earth, the formation of life would still require additional materials from meteorites and asteroids.
B) complex organic molecules can be produced by physical processes from inorganic components.
A spot where two continental plates are sliding past one another may be prone to A) volcanoes. B) earthquakes. C) tsunamis. D) wildfires.
B) earthquakes.
In a hybrid zone, ________ can occur if the reproductive barrier between two species isweak, as seen among cichlids in the murky waters of modern Lake Victoria. A) reinforcement B) fusion C) allopatric speciation D) reproductive isolation
B) fusion
Which of the following types of reproductive barriers separates a pair of insect species that could interbreed but for the fact that one lives on goldenrod plants and the other on autumn daisies in the same general area? A) temporal isolation B) habitat isolation C) behavioral isolation D) gametic isolation
B) habitat isolation
In the axolotl, development is altered. Adult axolotls retain features (external gills and aquatic life) that were juvenile in its ancestors, a phenomenon known as A) "evo-devo" B) paedomorphosis. C) punctuated evolution. D) homology.
B) paedomorphosis.
Organisms that possess more than two complete sets of chromosomes are said to be A) haploid. B) polyploid. C) diploid. D) hybrids.
B) polyploid.
The earliest discovered fossils are of ________ dating back to ________ years ago. A) single-celled eukaryotes; 4.5 billion B) prokaryotes; 3.5 billion C) algae; 1 billion D) fish; 600 million
B) prokaryotes; 3.5 billion
Two species that sometimes mate and produce vigorous but sterile offspring are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) hybrid breakdown.
B) reduced hybrid fertility.
A current leading hypothesis about the first system of inheritance in the earliest life-forms involves A) self-replicating DNA molecules (the "DNA world"; hypothesis). B) self-replicating RNA molecules aided by ribozymes. C) proteins that served as templates for RNA molecules, leading to the formation of DNA. D) self-replicating polypeptides aided by ribosomes.
B) self-replicating RNA molecules aided by ribozymes.
The model of species selection is analogous to natural selection. In this analogy, ________are like individuals within a population, and ________ is analogous to reproduction. A) major groups of organisms; extinction B) species; speciation C) genes; gene duplication D) families; interbreeding
B) species; speciation
The Monterey pine and the Bishops pine inhabit some of the same areas of central California. The Monterey pine releases pollen in February, while the Bishops pine does so in April. This is an example of ________ isolation. A) postzygotic B) temporal C) habitat D) mechanical
B) temporal
Scientists believe that a major factor promoting the adaptive radiation of mammals was probably A) their development of fur. B) the mass extinction of most dinosaurs, an event that opened up new ecological opportunities. C) internal fertilization. D) the origin and diversification of flowering plants.
B) the mass extinction of most dinosaurs, an event that opened up new ecological opportunities.
The fossil record shows that for many plant and animal groups, the time between speciation events A) is usually about 50,000 years. B) varies greatly, but averages 6.5 million years. C) is usually greater than 40 million years. D) is equivalent to the length of one hundred generations of a species.
B) varies greatly, but averages 6.5 million years.
Potassium-40 can be used to date ________ that are ________ old. A) fossils; thousands of years B) volcanic rocks and associated fossils; hundreds of millions of years C) potassium-rich fossils; millions of years D) carbon-containing materials; up to 75,000 years
B) volcanic rocks and associated fossils; hundreds of millions of years
One of the key contributions of the punctuated equilibrium model is that it helps explain A) why transitional fossils are more common than Darwin would have predicted. B) why transitional fossils tend to be rare and certain common fossil species remain unchanged for long time spans. C) how new species arise from hybridization events. D) why large, widespread populations tend to be the ones that evolve most rapidly and unpredictably.
B) why transitional fossils tend to be rare and certain common fossil species remain unchanged for long time spans.
Which provides the most general and correct description of the idea of a reproductive barrier? A) any feature (of geography, behavior, or morphology) that keeps one species from mating with another B) a biological difference between two species that prevents them from successfully interbreeding C) a geographic barrier that separates two species and prevents gene flow between them D) a difference in behavior that keeps two species from interbreeding
B)a biological difference between two species that prevents them from successfully
Speciation, or the formation of new species, is A. a form of microevolution. B. responsible for the diversity of life. C. necessary for natural selection and adaptation. D. an event that has occurred only a few times in the history of the planet.
B- responsible for the diversity of life
Over the past 400 years, humans have documented the extinction of more than ________species. This modern rate of species extinction is estimated to be ________ the normal extinction rate seen in the fossil record. A) 100; about the same as B) 400; about double C) 1,000; over 100 times greater than D) 10,000; at least 1 million times greater than
C) 1,000; over 100 times greater than
It is estimated that the modern continents began to take shape A) 1.3 million years ago. B) 650 million years ago. C) 65 million years ago. D) 6,000 years ago.
C) 65 million years ago
The 14C:12C ratio can be used to date fossils that are up to approximately how old? A) 100 million years B) 7 million years C) 75,000 years D) 7,500 years
C) 75,000 years
The earliest known flowering plants date to the A) Paleozoic. B) Triassic (early Mesozoic era). C) Cretaceous (late Mesozoic era). D) Cenozoic.
C) Cretaceous (late Mesozoic era).
Which of the following lines of evidence suggests that lungfishes evolved while Pangaea was intact? A) Modern lungfishes on different continents show similar patterns of behavior. B) Lungfishes are found today in Africa, Australia, and South America. C) Fossil lungfishes have been found on every continent except Antarctica. D) Lungfishes are restricted to Australia and neighboring islands.
C) Fossil lungfishes have been found on every continent except Antarctica.
Which of the following options correctly lists the varieties of life in the order that they appear in the geologic record, from earliest to most recent? A) reptiles, land arthropods, plants and fungi on land, flowering plants B) land arthropods, plants and fungi on land, flowering plants, reptiles C) plants and fungi on land, land arthropods, reptiles, flowering plants D) plants and fungi on land, land arthropods, flowering plants, reptiles
C) plants and fungi on land, land arthropods, reptiles, flowering plants
Geological evidence indicates that two landmasses became separated by a deep ocean channel 45 million years ago and have been moving apart ever since. You are studying a group of organisms that is widespread as a native part of the biota on both of the landmasses. What can you conclude about the group's evolutionary history? A) The group's ancestors were definitely present on the original landmass. B) The group's ancestors cannot have been present on the original landmass. C) If the group's ancestors could not move across the open ocean, it is very likely that they were present on the original landmass. D) The group's ancestors must have independently colonized each of the landmasses from a third location within the past 45 million years.
C) If the group's ancestors could not move across the open ocean, it is very likely that they were present on the original landmass.
What was the probable role of oxygen gas in the early stages of lifes appearance on Earth? A) Cellular respiration, which depends on oxygen availability, provided abundant energy to the first life-forms. B) Oxygen promoted the formation of complex organic molecules through physical processes. C) Oxygen gas tends to disrupt organic molecules, so its absence promoted the formation and stability of complex organic molecules on the early Earth. D) Abundant atmospheric oxygen would have created an ozone layer, which blocked out ultraviolet light and thereby protected the earliest life-forms.
C) Oxygen gas tends to disrupt organic molecules, so its absence promoted the formation and stability of complex organic molecules on the early Earth.
Plants and fungi first became established on land during the A) Archaean. B) Proterozoic. C) Paleozoic. D) Cenozoic.
C) Paleozoic.
Which of the following statements regarding the definition of species is false? A) The ecological species concept identifies species in terms of their ecological niches. B) The phylogenetic species concept defines a species as a set of organisms that shares a common ancestor and forms one branch on the tree of life. C) The morphological species concept relies upon comparing the DNA sequences of organisms. D) Under the biological species concept, the gap between species is maintained by reproductive isolation.
C) The morphological species concept relies upon comparing the DNA sequences of organisms.
Ancestral diploid wheat species had 2n = 14 chromosomes. What happened when two of these species hybridized? A) They produced a viable, fertile hybrid species with 14 chromosomes. B) They produced a hybrid species that could not complete mitosis, so it did not develop properly. C) They produced a hybrid species with 14 chromosomes that was sterile because the chromosomes from the two different parent species did not pair up properly in meiosis. D) They produced a hybrid species with 28 chromosomes.
C) They produced a hybrid species with 14 chromosomes that was sterile because the chromosomes from the two different parent species did not pair up properly in meiosis.
One of the strongest lines of evidence of a meteor or comet impact in the late Cretaceous is A) the extinction of the dinosaurs. B) a thin layer of potassium-40 in late Cretaceous fossil strata. C) a thin layer of iridium-enriched clay in late Cretaceous fossil strata. D) the warming of Earth's climate in the late Cretaceous.
C) a thin layer of iridium-enriched clay in late Cretaceous fossil strata.
The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes ________ speciation. A) punctuated B) sympatric C) allopatric D) biogeographic
C) allopatric
Another difference between the two groups is in how they hunt. Whales that hunt fish tend to travel in large pods (groups of whales) and vocalize often. Whales that hunt seals, however, tend to travel in very small groups and vocalize very little, likely because of the excellent hearing ability of seals. If these differences brought about speciation, the separation would be considered A) habitat isolation. B) temporal isolation. C) behavioral isolation. D) mechanical isolation.
C) behavioral isolation.
Over the past 500 million years, there have been ________ mass extinctions, and each time, at least ________ of the species on Earth became extinct. A) two; 25% B) five; 25% C) five; 50% D) twelve; 96%
C) five; 50%
Diane Dodd's experiments using fruit flies demonstrated that A) the evolution of reproductive barriers occurs much too slowly to produce measurable effects in the laboratory. B) new species can form in a single generation by the production of new reproductive structures. C) formation of a reproductive barrier between two populations is more likely if they experience and adapt to different environmental conditions. D) reproductive barriers usually are absolute: Either two populations are fully willing and able to interbreed, or they are strictly separated by a fully effective reproductive barrier.
C) formation of a reproductive barrier between two populations is more likely if they experience
Two populations that have been separated by a river are most likely to become separate species if A) fur color is different in the two populations. B) genes controlling ear development become different so that members of one population have much longer ears than the other. C) genes controlling molecules on the surface of the sperm that bind with egg receptors are different in the two populations. D) feeding habits are different in the two populations.
C) genes controlling molecules on the surface of the sperm that bind with egg receptors are different in the two populations.
Which of the following environments is thought to have promoted the dehydration synthesis of polypeptides and other macromolecules from smaller organic monomers on a prebiotic Earth? A) freshwater swamps and marshes B) deep-sea hydrothermal vents C) hot sand, clay, or rock along the seashore D) sediments at the bottom of the worlds oceans
C) hot sand, clay, or rock along the seashore
Which of the following types of reproductive barriers separates two flowering plant species that could interbreed but for the fact that one has a deep flower tube and is pollinated by bumblebees whereas the other has a short, narrow flower tube and is pollinated by honeybees? A) habitat isolation B) behavioral isolation C) mechanical isolation D) gametic isolation
C) mechanical isolation
Speciation has occurred when A) two populations of organisms have been separated for a very long time. B) a change in allele frequency has occurred. C) organisms of one population do not recognize the mating call of another population and so mating does not occur. D) offspring of mating from members of two different populations are able to mate with members of either population.
C) organisms of one population do not recognize the mating call of another population and so mating does not occur.
Two species that occasionally mate and produce zygotes, but that have incompatible genes that prevent the resulting embryo from developing, are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) hybrid breakdown.
C) reduced hybrid viability.
Mass extinctions A) remove many species, but they are usually replaced within a million years or less by an even greater diversity of life. B) mainly serve to "weed out"; poorly adapted organisms and make room for new, better adapted species. C) remove well-adapted species and groups from the Earth, so that it may take millions of years for species diversity to recover. D) are caused by human activity and did not occur prior to the expansion of the Earth's human population.
C) remove well-adapted species and groups from the Earth, so that it may take millions of years for species diversity to recover.
Some RNA molecules can function like enzymes. These particular enzymatic RNA molecules are called A) ribosomes. B) mRNA. C) ribozymes. D) RNase.
C) ribozymes.
One of the finest available sequences of fossils shows how horses have changed slowly and by subtle steps from small shrub-browsing ancestors to the large, grass-grazing modern horse. A large number of fossil species have been named, and it is often difficult to decide on the identity of a fossil horse because transitional forms are common. The species concept most applicable to these organisms would be A) the biological species concept. B) the ecological species concept. C) the morphological species concept. D) the phylogenetic species concept.
C) the morphological species concept.
The ________ suggests that speciation occurs in brief spurts. A) adaptive model of the origin of species B) allopatric speciation model C) gradual model of the origin of species D) punctuated equilibrium model
D) punctuated equilibrium model
In the North Pacific Ocean, two groups of the same species of killer whales (Orcinus orca) appear to be forming two different species based on what they eat. One group eats fish and the other eats mammals such as seals. Scientists can tell what they eat based on their teeth, because whales that feed on fish have significantly different wear patterns. 3) Which of the following would not be a useful procedure to perform in determining whether or not this speciation has occurred? A) Compare teeth of whales alive today to teeth of whales in ancient samples. B) Compare DNA samples from fish-eaters and mammal-eaters. C) Compare stomach contents of whales from each of the two populations. D) Compare body shape of whales from each population.
D) Compare body shape of whales from each population.
Which highly reactive gas was probably absent from the Earth's primitive atmosphere? A) methane B) carbon dioxide C) O2 (oxygen gas) D) water vapor
D) O2 (oxygen gas)
In which of the following situations would speciation be most likely to occur? A) A population of juniper shrubs is split in two by a canyon. Every year, strong winds carry a small amount of the shrubs pollen across the canyon. B) A Japanese mollusk species whose larvae are often carried from port to port in ship bilge (waste) water now flourishes in San Francisco Bay, a busy commercial port. C) Bighorn sheep occupy mountains from Canada to Death Valley in Southern California, interbreeding all the way. The populations at the two ends of the range live in very different environments. D) Seven monkeys escape from an enclosure. To everyones surprise, they establish a small but viable population, coexisting successfully with humans in a partly suburban environment very different from their native African habitat.
D) Seven monkeys escape from an enclosure. To everyone's surprise, they establish a small but viable population, coexisting successfully with humans in a partly suburban environment very different from their native African habitat.
A group of ants escaped from a picnic basket carried to the top of a mountain and thrived in this area where there were no other ants. Many years later descendants of these ants crawled into a picnic basket on the mountain and traveled back to the valley from which their ancestors had come. Which of these observations would cause you to conclude that the ants on top of the mountain had become a different species from those in the valley? A) The mountain ants and valley ants were different colors. B) The mountain ants and valley ants were different sizes. C) The mountain ants ate different food than the valley ants. D) The mountain ants could not mate with the valley ants.
D) The mountain ants could not mate with the valley ants.
If H. floresiensis were reunited with H. erectus at a much later date, but the two populations could no longer interbreed, it would be correct to conclude that A) H. floresiensis is no longer fertile as a species. B) the two groups had been isolated for more than 50,000 years. C) H. floresiensis has become less fit than H. erectus. D) a reproductive barrier had evolved.
D) a reproductive barrier had evolved.
Two populations of organisms belong to the same biological species when they A) cannot mate with each other because mating occurs at different times. B) use different types of behaviors or physical features to attract mates. C) have anatomical features that make it difficult for organisms from the two populations to mate with one another. D) encounter each other, mate, and produce viable, fertile offspring under natural conditions.
D) encounter each other, mate, and produce viable, fertile offspring under natural conditions.
Feathers are an example of a/an ________; they originally evolved ________. A) homology; for flight B) adaptation; for some other function and only later became adapted for flight C) exaptation; in anticipation of future use in the development of flight D) exaptation; for some other function and only later became adapted for flight
D) exaptation; for some other function and only later became adapted for flight
Which of the following options lists major events in the history of life on Earth in the proper order, from earliest to most recent? A) first prokaryotes, photosynthesis, colonization of land by plants and fungi, first eukaryotes B) first eukaryotes, photosynthesis, colonization of land by plants and fungi, first prokaryotes C) first prokaryotes, first eukaryotes, photosynthesis, colonization of land by plants and fungi D) first prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi
D) first prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi
Which of the following types of reproductive barriers separates two species of sea cucumbers whose sperm and eggs often bump into each other but do not cross-fertilize because of incompatible proteins on their surfaces? A) temporal isolation B) habitat isolation C) mechanical isolation D) gametic isolation
D) gametic isolation
Under the biological species concept, a species is a group of organisms that A) are physically similar. B) share a recent common ancestor. C) live together in a location and carry out identical ecological roles. D) have the potential to interbreed in nature and produce fertile offspring.
D) have the potential to interbreed in nature and produce fertile offspring.
Two species interbreed occasionally and produce vigorous, fertile hybrids. When the hybrids breed with each other or with either parent species, however, the offspring are feeble or sterile. These species are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) hybrid breakdown.
D) hybrid breakdown.
The findings of Pasteur and others have established that A) living organisms regularly self-assemble (arise spontaneously) from nonliving matter. B) living organisms do not arise from nonliving matter today, nor did they arise from nonlife in the past. C) advanced organisms cannot arise from nonliving matter, but simple microbial life often does arise from nonlife today. D) life does not arise from nonliving matter today, but in the conditions of early Earth, such an event could have occurred.
D) life does not arise from nonliving matter today, but in the conditions of early Earth, such an event could have occurred.
If an isotope has a half-life of 4 million years, and a fossil is 16 million years old, how much of the original isotope will be found in the fossil? A) one-half of the original amount B) one-quarter of the original amount C) one-eighth of the original amount D) one-sixteenth of the original amount
D) one-sixteenth of the original amount
When plants undergo allopatric speciation, an initial reproductive barrier is often A) polyploidy. B) gametic isolation. C) temporal isolation. D) pollinator choice.
D) pollinator choice.
The biological species concept is A) applicable to all forms of life, past and present. B) applicable to all present life-forms but not to fossil organisms whose reproductive behavior cannot be observed. C) easy to apply to all present sexually reproducing organisms but harder to apply to asexual organisms and fossils. D) sometimes difficult to put into practice even for present sexual organisms and useless for asexual organisms and fossils.
D) sometimes difficult to put into practice even for present sexual organisms and useless for asexual organisms and fossils.
The Mesozoic era is often called the age of reptiles. Which of the following also occurred during this era? A) the origin of animals in the oceans B) the appearance of the first plants on land C) the appearance of the first animals (tetrapods and insects) on land D) the appearance of the first mammals and flowering plants on land
D) the appearance of the first mammals and flowering plants on land
Most polyploid species arise from A) a single diploid parent plant. B) a single triploid parent plant. C) a single tetraploid parent plant. D) the hybridization of two parent species.
D) the hybridization of two parent species.
According to "evo-devo"; thinking, an organism's body form can be substantially changed A) only through multiple mutations that produce a large number of new proteins. B) through mutations that change sexually selected traits. C) only when changes in the environment directly alter the major protein-coding genes in the organism's genome. D) through mutations or changes in the expression of one or a few genes that regulate development.
D) through mutations or changes in the expression of one or a few genes that regulate development.
When a tetraploid flower pollinates a diploid flower of the parental species, the resulting offspring will be A) pentaploid and sterile. B) diploid and fertile. C) triploid and fertile. D) triploid and sterile.
D) triploid and sterile.
Which of the following would a biologist describe as microevolution? A) the formation of new species B) the extinction of species C) dramatic biological changes, such as the origin of flight, within a taxon D) a change in the gene pool of a population from one generation to the next
D. a change in the gene pool of a population from one generation to the next