Bio Ch. 15

About 2.2 billion years ago, oxygen released by early _____ became fairly abundant in the atmosphere, enabling the evolution of _____. A. photosynthesis; cellular respiration B. cellular respiration; photosynthesis C. photosynthesis; anaerobic prokaryotes D. photosynthesis; prokaryotes

A

According to the findings of researchers in the field known as "evo-devo," what kinds of genetic changes are often involved in reshaping the body forms of organisms? A. Changes in genes that control development have big effects by altering the developmental process. B. One or more mutations re-create the genome of a past ancestor, leading to formation of a "living fossil" species. C. The total number of genes is increased to provide for any increase in an organism's complexity. D. New genes arise and produce new classes of proteins.

A

Earth's continents and seafloors together form a thin outer layer of the planet called the A. crust. B. Pangean supercontinent. C. strata. D. biosphere.

A

What do earthquakes, volcanoes, and the formation of mountain ranges have in common? A. They are all the result of continental drift and are common near the boundaries of the crustal plates. B. They only occur on islands. C. They are all disasters that permanently eliminate life and its diversity. D. They are all the result of continental drift and are common near the centers of the crustal plates.

A

What is a likely explanation for a substantial change in body form between two closely related taxa? A. changes in the number, sequence, and regulation of developmental genes B. simultaneous mutation of several protein-coding genes C. mutation of an existing gene to create a new type of structural protein D. mutations to produce new enzymes that encourage growth of some structures and disrupt growth of others

A

You are studying a group of related rodent species that are native to central portions of South America and Africa. Both the rodents and their fossils are entirely absent from other continents. These rodents slowly disperse over land, but do not cross areas of salt water. With reference to the figure below, when did this group probably originate? A. in the Mesozoic, about 135 million years ago B. in the recent Cenozoic, less than 50 million years ago C. in the late Mesozoic, about 65 million years ago D. in the late Paleozoic, about 251 million years ago

A

Biologists are studying two species whose DNA is known to differ by 10%. Knowledge of which of the following would be least important in calibrating a molecular clock to determine how rapidly evolution has proceeded with these two species? A. a geological event that separated the species at a particular time. B. the function of each of these regions of DNA C. the fossil record of these two species D. the time of divergence of closely related species

B

Earth probably formed __________ years ago, and the earliest evidence of life comes from fossils that are __________ years old. A. 6,000; 6,000 B. 4.6 billion; 3.5 billion C. 10 billion; 4.6 billion D. 3.9 million; 2.0 billion

B

Fish that were ancestral to the first amphibians may have had limbs that were used for moving through underwater vegetation, and were later adapted for use in walking on land. If so, the limbs were an example of _____. A. a clade B. an exaptation C. paedomorphosis D. convergent evolution

B

Hot sand, clay, or rock may have played an important role in the origin of life because _____. A. early life-forms probably utilized minerals present there B. evaporation of seawater from these surfaces could have concentrated monomers, leading to the formation of polymers through dehydration synthesis C. they would have heated monomers enough to cause them to spontaneously bind and form polypeptides and other polymers D. they are often colonized by bacteria and algae

B

In accordance with the principle of parsimony, scientists prefer A. phylogenetic trees with many small clades to those with a few major clades. B. phylogenetic trees that minimize the number of evolutionary changes. C. phylogenetic trees in which adaptations repeatedly arise, disappear, and reappear. D. the Linnaean system of nomenclature to the use of common names.

B

Plants and fungi first became established on land during the A. Archaean. B. Paleozoic. C. Cenozoic. D. Proterozoic.

B

Spontaneous generation of life from nonlife __________. A. was a theory first proposed by Louis Pasteur B. likely occurred once or at most a few times about 3.9 billion years ago C. occurs rarely under current conditions D. occurs in the tropical rain forest today

B

Structures that evolved from the same structure in a common ancestor are A. heterologous. B. homologous. C. convergent adaptations. D. analogous.

B

The "big bang" that produced the universe is thought to have occurred A. 4.6 billion years ago. B. 12 to 14 billion years ago. C. 4 million years ago. D. 40 to 50 billion years ago.

B

The three-domain system A. no longer recognizes eukaryotes as a monophyletic group. B. subdivides the prokaryotes into two different domains. C. separates plants, animals, and fungi into domains. D. subdivides the eukaryotes into two different domains.

B

This figure shows the hierarchy of classification of the cow, Bos primigenius. The greatest number of organisms would be found in A. box A. B. box I. C. box E. D. box B.

B

This figure shows the hierarchy of classification of the cow, Bos primigenius. The three boxes at the base of the hierarchy represent A. phyla. B. domains. C. classes. D. kingdoms.

B

We generally consider inheritance to flow from one generation to the next along independent lines of descent. Thus, the tree of life begins with a single root and spreads out along branches that, once separated, never rejoin. What phenomenon challenges this model of evolution? A. neutral variation B. horizontal gene transfer C. inheritance D. vertical gene transfer

B

What is an exaptation? A. a single mutation that produces a brand-new, fully functional structure in a single step B. a structure that initially served a different purpose becoming adapted for a new function C. gradual refinement of a feature for a particular function D. evolution of new traits through modification of developmental genes

B

Which highly reactive gas was probably absent from the Earth's primitive atmosphere? A. carbon dioxide B. O2 (oxygen gas) C. water vapor D. methane

B

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. plants and fungi on land, land arthropods, reptiles, flowering plants C. land arthropods, plants and fungi on land, flowering plants, reptiles D. plants and fungi on land, land arthropods, flowering plants, reptiles

B

_____ evolution leads to _____ structures. A. Gradual; analogous B. Convergent; analogous C. Divergent; homologous D. Convergent; homologous

B

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. 10,000; at least 1 million times greater than B. 400; about double C. 1,000; over 100 times greater than D. 100; about the same as

C

The earliest known land plants date to the A. Precambrian. B. Carboniferous (late Paleozoic era). C. Ordovician (early Paleozoic era). D. Jurassic (Mesozoic era).

C

The example of ocean and lake stickleback fishes indicates that morphology can be altered A. by environmental factors (in this case, pollution). B. by the elimination of a gene (Pitx1) from a population, which leads to loss of the trait (body armor and spines). C. by altering the expression of a developmental gene in some parts of the body but not others. D. only by changing the sequences of protein-coding genes.

C

Which of the following best describes how the breakup of Pangaea affected evolution? A. Extensive glaciations caused many extinctions. B. Mammals had an opportunity to become dominant. C. Geographic isolation led to speciation and the formation of unique faunas and floras on the different continents. D. Shallow marine habitat became scarcer, and terrestrial climates became harsher.

C

Which of the following is thought to have been the first step in the origin of life? A. formation of proteins B. replication of primitive genes C. formation of organic monomers such as amino acids D. formation of lipid membrane-bound spheres

C

Why is rRNA such a useful tool in molecular systematics? A. Only advanced organisms have rRNA, so it is a useful derived character. B. It evolves quite rapidly. C. It evolves quite slowly, allowing comparisons to be made between distantly related organisms such as eukaryotes and bacteria. D. It doesn't change at all, so it is a useful control to ensure that the sequence data is accurate.

C

You have found a fossil of a soft-bodied animal. You suspect it is from the late Proterozoic (about 600 million years old). Which isotope would be the best choice to approximate the actual age of the fossil? A. phosphorus-32 B. carbon-12 C. potassium-40 D. carbon-14

C

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. punctuated evolution. B. "evo-devo." C. homology. D. paedomorphosis.

D

It has been proposed that the first self-replicating molecules were __________. A. phospholipids B. DNA molecules C. viruses D. RNA molecules

D

Members of what was once the kingdom Monera are now divided into two major domains called the __________. A. Protista and Archaea B. Fungi and Animalia C. Bacteria and Plantae D. Archaea and Bacteria

D

Systematic biologists have used a wide variety of traits to reconstruct the phylogenies of particular groups of organisms. Which type of trait can also be analyzed to estimate the divergence times between taxa? A. structural features B. developmental features C. behavioral traits D. gene sequences

D

The technique called radiometric dating is based on A. the assumption that radioactive isotopes accumulate in fossils at a constant rate. B. the use of fossils of known age to determine how fast carbon-14 decays. C. the formation of radioactive molecules in rocks after they are laid down. D. the steady, clocklike decay of certain radioactive isotopes over time.

D

Which of the following is an example of exaptation? A. Wings of bats and wings of birds are homologous. B. Mutation rates can increase at higher temperatures. C. Wings are longer in some birds than others. D. Human middle ear bones are derived from ancestral gill arch tissue.

D

Which of the options places major events in the history of life on Earth in the proper chronological order from earliest to most recent? A. first prokaryotes; photosynthesis; first multicellular life on land; first multicellular eukaryotes B. photosynthesis; first prokaryotes; first multicellular life on land; first multicellular eukaryotes C. photosynthesis; first multicellular eukaryotes; first multicellular life on land; first prokaryotes D.

D

Which pair of organisms, if found together in the same well-defined fossil layer, would cause a major rethinking of our current understanding of the fossil record? A. dinosaurs and amphibians B. prokaryotes and bony fish C. marine algae and bony fish D. dinosaurs and primates

D

While out canoeing, you discover the remains of a dugout canoe in a river bed. You remove a sample of the wood and have it analyzed for carbon-14. It has one-quarter (25%) of the carbon-14 expected in a living tree. About how long ago did the tree that the canoe was made from die? A. approximately 23,000 years B. about 5,730 years C. about 573 years D. about 11,500 years

D

A disaster such as a meltdown in a nuclear power plant requires close examination of potential impacts on organisms. Which of the following would be useful to biologists in such a situation? A. Examine the mutation rate of species in the area. B. Use a molecular clock to compare of genes of a species that lives near the nuclear plant with those of the same species thousands of miles away. C. Use radiometric dating to determine if new species are forming. D. Measure continental drift to determine if the disaster had accelerated movement of continents.

A

A radioactive isotope has a half-life of 1.2 billion years. As measured by the presence of the isotope and its stable decay product, a rock originally contained 10 grams of the radioactive isotope, and now contains 1.25 grams. How many years old is the rock? A. 3.6 billion years B. 0.3 billion years C. 12 billion years D. 10,000 years

A

According to "evo-devo" thinking, an organism's body form can be substantially changed A. through mutations or changes in the expression of one or a few genes that regulate development. B. only through multiple mutations that produce a large number of new proteins. C. through mutations that change sexually selected traits. D. only when changes in the environment directly alter the major protein-coding genes in the organism's genome.

A

Scientists evaluating the Cretaceous mass extinction have concluded that A. an asteroid impact was probably the triggering event for the extinction. B. ecological factors such as disease and competition probably caused the dinosaurs to go extinct. C. only an extraterrestrial impact could have caused such a big extinction event. D. climate change would not have been involved in producing the extinctions.

A

Some RNA molecules can function like enzymes. These particular enzymatic RNA molecules are called A. ribozymes. B. ribosomes. C. RNase. D. mRNA.

A

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 with a survey of eye structure in the molluscs? A. There are many intermediate stages of eye complexity that fulfill different adaptive functions. B. 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. C. The argument has a great deal of merit. Only full-blown image-forming eyes are present in modern organisms. D. The vertebrate eye works in a way that is completely different from the eyes found in molluscs and other invertebrates.

A

Based on your review of Table 15.6, The Geologic Record, what types of markers are used to separate eras? A.The transition point for each era is marked by a mass extinction or significant species radiation. B. The estimated time of life on Earth was divided by four. Each unit represents one era. C. Each time a new phylum emerged, it marked the beginning of a new era. D. The transition point for each era is marked by a catastrophic geologic event.

A

Cacti are native to deserts in the Americas, whereas cactus-like euphorbs are native to African deserts. The two plant groups are not closely related, and the euphorbs have normal broad-leaved plants such as the Christmas poinsettia in their ancestry. The most likely explanation for the similarity of some euphorbs to cacti is __________. A. convergent evolution B. coevolution C. homology D. a founder effect

A

Climate and sea-level changes caused by the formation of the supercontinent Pangaea _____. A. were a significant factor leading to the Permian mass extinctions of terrestrial and marine life B. promoted milder living conditions and accelerated the evolution of Permian life C. occurred well after the Permian extinction D. led to the late Cretaceous extinction of the dinosaurs

A

Evidence indicates that the first life arose _____, the first animals arose _____, and the first large organisms on land arose _____. A. at least 3.5 billion years ago; 600 million years ago; 480 million years ago B. about 350 million years ago; 60 million years ago; 50 million years ago C. over 3.5 billion years ago; over 1.5 billion years ago; 2 billion years ago D. about 35 billion years ago; 6 billion years ago; 5 billion years ago

A

Evolutionary trends _____. A. can occur if the environment changes to promote the success of organisms with a similar set of traits; such trends may reverse themselves if environmental conditions change course B. always promote increased complexity and intelligence; these trends reached their goal with the evolution of humans C. tend to lead to increasing disorder, as required by the physical law of increasing entropy D. cannot occur because evolution is a chance, or random, process

A

Homeotic genes are responsible for _____. A. determining the location and pattern of structural features such as limbs B. influencing human emotional response to juvenile traits such as bulging cheeks and a small chin C. making several structural proteins in organisms D. producing enzymes that control metabolic pathways in cells

A

In 1942 a scientist testing part of a radar system discovered that a candy bar in his pocket had melted. Intrigued, he tried placing an egg near the system he was working on; it exploded and splattered him with hot egg. In this way it was discovered that part of the radar system could be used to cook foods, which led to the development of the microwave oven. When this kind of repurposing occurs in biological systems, it is called A. exaptation. B. adaptive radiation. C. paedomorphosis. D. mutation.

A

In the three-domain system, the eukaryotes are represented A. only within the domain Eukarya. B. only within the domain Archaea. C. in all three domains. D. only within the kingdom Protista.

A

It is estimated that the modern continents began to take shape A. 65 million years ago. B. 1.3 million years ago. C. 650 million years ago. D. 6,000 years ago.

A

It's easier to say "cat" than Felis catus. What is the key advantage of using the Latin binomial in this case? A. There are many cat species, but Felis catus specifically identifies the domestic cat and can be understood by scientists worldwide. B. The term cat is too specific. Felis catus is a broader category that can be used to describe any of several closely related species. C. It sounds more scientific to use Latin names. D. Felis catus is more easily understood by the general public.

A

Mass extinctions A. remove well-adapted species and groups from the Earth, so that it may take millions of years for species diversity to recover. B. remove many species, but they are usually replaced within a million years or less by an even greater diversity of life. C. mainly serve to "weed out" poorly adapted organisms and make room for new, better adapted species. D. are caused by human activity and did not occur prior to the expansion of the Earth's human population.

A

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. Different adaptive trends will probably be favored in the new climatic environment. B. Ongoing processes of adaptation will continue because of evolutionary inertia. C. Adaptation will cease because cool, wet conditions are generally favorable for life. D. Current adaptive trends will continue, but organisms will now also have to add on adaptations to deal with cool, wet conditions.

A

Potassium-40 can be used to date ________ that are ________ old. A. volcanic rocks and associated fossils; hundreds of millions of years B. carbon-containing materials; up to 75,000 years C. fossils; thousands of years D. potassium-rich fossils; millions of years

A

Scientists believe that a major factor promoting the adaptive radiation of mammals was probably A. the mass extinction of most dinosaurs, an event that opened up new ecological opportunities. B. their development of fur. C. internal fertilization. D. the origin and diversification of flowering plants.

A

Species A, B, and C are in the same phylum. Species A and species B are in the same order. Species C is in a different order. From this information you can conclude with certainty that __________. A. species A and B are in the same class B. species A and B are in the same family C. species B and C share a more recent ancestor than do species A and B D. all three species are members of the same genus

A

Stanley Miller's experiments involved generating electrical sparks (simulating lightning) in a lifeless vessel containing hydrogen gas, water vapor, methane, and ammonia. The result was that _____. A. amino acids and other complex molecules formed in the vessel. This suggested that many of the organic building blocks of life could have arisen on a lifeless early Earth B. cell-like structures (spherical lipid membranes) formed. This finding helped scientists model how the first cells arose C. nothing much happened. This confirmed that physical processes cannot produce complex molecules D. new life-forms arose in the vessel. This clearly demonstrated that life can arise from nonlife in the proper conditions

A

Stromatolite fossils that formed 3.5 billion years ago indicate that _____. A. life must have arisen quite a bit earlier, perhaps 3.9 billion years ago B. life originated 3.5 billion years ago C. the first organisms were eukaryotes D. the first life-forms were photosynthetic

A

The Mesozoic era is often called the age of reptiles. Which of the following also occurred during this era? A. the appearance of the first mammals and flowering plants on land B. the appearance of the first animals (tetrapods and insects) on land C. the appearance of the first plants on land D. the origin of animals in the oceans

A

The San Andreas Fault in California is an example of a particular kind of junction between crustal plates. This kind of junction is called _____. A. a strike-slip fault B. a divergent plate C. the Pacific plate D. continental drift

A

The end-Cretaceous extinctions were followed by the _____. A. adaptive radiation of mammals B. appearance of the first land plants C. adaptive radiation of dinosaurs D. appearance of hard-shelled marine organisms

A

The existence of nest-building in crocodiles and birds led to a prediction that this behavior was also present in ________. A. fossil dinosaurs B. Komodo dragons C. invertebrates D. fossil lizards

A

The flight of a bee and the flight of a hummingbird are similar in many ways, such as in speed of wing movement, ability to hover, and ability to back up. Also, both hummingbirds and bees eat nectar, a diet shared by few other birds. In these respects, hummingbirds are more similar to bees than they are to other birds, such as robins and ducks. Yet no one would classify hummingbirds with bees because their similar flight capabilities and diet __________. A. evolved independently in hummingbirds and bees B. do not change the fact that hummingbirds and bees are genetically isolated from one another C. are ancestral in bees but derived in hummingbirds D. are homologous rather than analogous

A

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. species; speciation B. genes; gene duplication C. major groups of organisms; extinction D. families; interbreeding

A

The process through which species not closely related may come to resemble one another if they live in a similar environment is known as A. convergent evolution. B. coevolution. C. homology. D. paedomorphosis.

A

The similarities in function of hummingbird wings and the wings of a butterfly reflect A. analogy but not homology. B. analogy and homology. C. homology but not analogy. D. homology through convergent evolution.

A

Which of the following is the correct presentation of a species name? A. Homo erectus (italics) B. Homo erectus C. Homo Erectus (italics) D. homo erectus

A

Which option accurately describes continental drift? A. Crustal plates floating on the mantle change position relative to one another. B. The shape and relative positions of coastlines change due to changes in sea level. C. The continents floating on the oceans change position relative to one another. D. Continents float and slide around on a stable underlying crust.

A

You compare homologous nucleotide sequences among several pairs of species with known divergence times. A pair of species that diverged 1 million years ago has two nucleotide differences, a pair that diverged 2 million years ago has four nucleotide differences, and a pair that diverged 3 million years ago has six nucleotide differences. You have sequence data for another pair of species for which the divergence time is unknown. There are five nucleotide differences between them. Based on your clock, when did their line of ancestry diverge? A. 2.5 million years ago B. 3 million years ago C. 3.5 million years ago D. 2 million years ago

A

You set your time machine for 3 billion years ago and push the start button. When the dust clears, you look out the window. Which of the following describes what you would probably see? A. green scum in the water B. plants and animals very different from those alive today C. a cloud of gas and dust in space D. land and water that are sterile and devoid of life

A

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. Mesozoic D. Cretaceous

B

Careful analysis of many types of organisms suggests that the amazingly complex camera-like eyes of vertebrates and cephalopod molluscs (octopuses and squids) formed through _____. A. inheritance from a common ancestor that also had camera-like eyes B. gradual refinements that occurred independently in the vertebrate and cephalopod lineages to produce similar camera-like eye structures C. a dramatic mutation in both the vertebrate and cephalopod lineages that produced a fully functional eye in a single step D. two different independent origins of vision based on a different set of genes from those used in more primitive eye designs

B

Creationists sometimes disparage the experiments of Miller and Urey (apparatus illustrated below), pointing out that they did not make all of the amino acids we see today in any given run of the experiment. This criticism misses the point of the Miller-Urey experiments, as they intended to demonstrate __________. A. how the first functional cells originated B. that organic molecules can be made from inorganic building blocks in the absence of living organisms C. that they could build macromolecules (especially functional proteins) in the absence of living organisms D. the exact makeup of the atmosphere on the early Earth

B

Ever since Darwin, systematics has tried to A. keep classification and naming as a practical science, separate from controversies involving evolution. B. classify species in groups that reflect evolutionary relationships. C. prove the existence of evolution using laboratory experiments. D. organize species into groups based on logical categories.

B

How can a phylogenetic tree be used to make predictions? A. Features found in one clade are likely to be found in other clades inhabiting different environments. B. Features shared between two groups are likely to have been present in their common ancestor. C. An existing organism's characteristics can be confidently assumed to fit the patterns in the tree. This procedure eliminates the need to collect data about organisms through direct observation or sampling. D. Current trends of evolution will continue into the future. Complex models can be used to accurately predict future branching patterns and the nature of future adaptations.

B

How can the success of one group of organisms promote the adaptive radiation of a second group? A. by filling most of the available niches, which forces the second group to evolve greater diversity B. by providing new food resources, habitats, etc. for the second group C. by preying on the second group, which hastens its adaptation D. by competing with the second group, promoting its adaptive radiation

B

How is the merging of continents to form Pangaea believed to have altered Earth's environments at the end of the Paleozoic era? A. It made the climate warmer and moister for terrestrial organisms in the center of the new landmass. B. Shallow coastal areas were drained, leading to the extinction of many marine species. C. It prompted an immediate increase in Earth's biodiversity. D. It eliminated all multicellular eukaryotes, allowing evolution to start anew.

B

If all of Earth's history were compressed into an hour, humans would first appear less than A. 10 minutes ago. B. 1 second ago. C. 1 minute ago. D. 10 seconds ago.

B

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-sixteenth of the original amount C. one-quarter of the original amount D. one-eighth of the original amount

B

If species A and species B are in the same family, and species C is in a different family, and if the classification accurately reflects phylogeny, then you can infer that __________. A. A is more closely related to C than B is to A B. A and B have a more recent common ancestor than do A and C C. C is more closely related to A than A is to B D. A and C have a more recent common ancestor than do A and B

B

In the figure below, consider the possibility that the iguana shares a recent common ancestor with the beaver. In the iguana's lineage, hair, mammary glands, and gestation were lost. The principle of _____ suggests that this tree is not the best hypothesis about how the taxa are related. A. increasing complexity B. parsimony C. evolutionary progress D. evolutionary irreversibility

B

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 iridium-enriched clay in late Cretaceous fossil strata. C. a thin layer of potassium-40 in late Cretaceous fossil strata. D. the warming of Earth's climate in the late Cretaceous.

B

The Permian extinction, which occurred about 251 million years ago, resulted in the extinction of _____. A. 100% B. about 96% of all marine animals C. about 10% of all marine animals D. about 50% of all marine animals

B

The body shapes of porpoises and sharks are similar in appearance. Yet recent ancestors to the porpoise were four-limbed terrestrial mammals. Therefore, the streamlined shapes of these two animals are an example of _____. A. homology B. analogy (similarity due to convergent evolution) C. exaptation D. neutral variation

B

The branching "tree of life" analogy A. does not describe ecological interactions between species, so it should be replaced by the web of life. B. fails to account for horizontal gene transfer, in which species on different branches exchange genes. C. has been discredited because it does not help us understand evolutionary relationships among organisms. D. accurately reflects evolution. Once a split occurs, species on different branches evolve absolutely independently.

B

The earliest known flowering plants date to the A. Triassic (early Mesozoic era). B. Cretaceous (late Mesozoic era). C. Paleozoic. D. Cenozoic.

B

The findings of Pasteur and others have established that A. living organisms regularly self-assemble (arise spontaneously) from nonliving matter. B. life does not arise from nonliving matter today, but in the conditions of early Earth, such an event could have occurred. C. advanced organisms cannot arise from nonliving matter, but simple microbial life often does arise from nonlife today. D. living organisms do not arise from nonliving matter today, nor did they arise from nonlife in the past.

B

The first fossil of Archaeopteryx, which lived about 150 million years ago, was found in the Solnhofen Quarry in Germany. Archaeopteryx has an interesting collection of characters that led to the hypothesis that it represented an evolutionary transition between modern-day birds and small bipedal dinosaurs. The fossil reveals the imprint of feathers, which connect Archaeopteryx to birds, although they do not present direct evidence of flight. Unlike birds, however, Archaeopteryx was shown by the fossil record to have had teeth, functional claws on the wings that may have been used for climbing trees or holding prey, and a long, bony tail. Birds have a fused collarbone, which was found in Archaeopteryx as well. However, the structure of the sternum differed between the two. In birds, the sternum is keeled (raised and slightly concave); the keel of the sternum serves as an attachment site for the flight muscles. Archaeopteryx had a flat sternum, similar to that found in reptiles. The feathers of Archaeopteryx may have been used for flight. However, it is likely that they were originally used for A. protection from predators. B. insulation. C. nest building. D. protection from parasites.

B

The first polymers were formed through dehydration synthesis. According to the experimental evidence, how did this process work? A. Very high concentrations of salt are thought to have spurred abiotic dehydration synthesis, forming the first polypeptides and other polymers. B. Hot rocks, sand, or clay concentrated a dilute solution of organic monomers from seawater, leading to spontaneous abiotic synthesis of polypeptides and other polymers. C. Extreme heat from volcanic vents on the seafloor caused monomers to spontaneously form complex polymers. D. Abiotically generated enzymes catalyzed dehydration synthesis of the first polypeptides and nucleic acids.

B

What information is needed to calibrate a molecular clock and use it to estimate the time that has passed since two species shared a common ancestor? A. You need the gene sequences for both of the species, and you must know the ratio of radioactive isotopes to stable products in the DNA of each species. B. You need to know the gene sequences for both of the taxa plus those of several related taxa. For at least three pairs of those taxa, you need good estimates of divergence times based on the fossil record. C. You need the gene sequences for both of the species, along with those of several related taxa. D. You only need the gene sequences for both of the species.

B

When analyzing relationships among a particular group of taxa, how does a biologist decide which trees are the most parsimonious? A. The most parsimonious tree always arranges species from simpler to more complex over time. B. The most parsimonious tree produces the observed traits in the organisms with the lowest number of evolutionary changes. C. The most parsimonious tree has the fewest number of branch tips (twigs) on it. D. The most parsimonious tree can be found by matching the phylogeny to known evolutionary trends.

B

Which comparison accurately states why phylogenetic trees based on molecular data can be more informative than those based on morphology? A. Molecular data is easier to obtain for fossil organisms. B. Molecular data is often more helpful in discovering relationships among very closely or very distantly related species. C. Molecular systematics uses the principle of parsimony, which is not used to build trees using morphological data. D. Molecular data are cheap and easy to obtain, whereas morphological studies require expensive laboratory equipment.

B

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. sediments at the bottom of the world's oceans B. hot sand, clay, or rock along the seashore C. deep-sea hydrothermal vents D. freshwater swamps and marshes

B

Which of the following organisms make up the monophyletic clade derived from the ancestor at node 3 (Gestation) in the figure shown below? A. duck-billed platypus, red kangaroo, and the North American beaver B. red kangaroo and North American beaver C. eastern box turtle, duck-billed platypus, red kangaroo, and North American beaver D. red kangaroo

B

Why does Australia have a great diversity of marsupials (pouched mammals) whereas North America has a great diversity of placental mammals? Refer to the figure below as you answer. A. Placental mammals cannot survive in the harsh conditions of Australia, so after the continent became isolated the placental mammals evolved to become marsupials. B. The landmass that broke away to form Australia initially had both marsupials and placental mammals, but the few placental species soon went extinct. The marsupials then diversified in isolation on Australia, whereas placental mammals diversified elsewhere. C. After a long period of coexistence, marsupials out-competed placental mammals in Australia. D. Marsupials originated in Australia after the breakup of the continents.

B

A current leading hypothesis about the first system of inheritance in the earliest life-forms involves A. proteins that served as templates for RNA molecules, leading to the formation of DNA. B. self-replicating DNA molecules (the "DNA world" hypothesis). C. self-replicating RNA molecules aided by ribozymes. D. self-replicating polypeptides aided by ribosomes.

C

A spot where two continental plates are sliding past one another may be prone to A. volcanoes. B. wildfires. C. earthquakes. D. tsunamis.

C

A systematist includes a lizard in a phylogenetic analysis of relationships among bird families. In this analysis, the lizard would be treated as A. a derived group. B. an analogous group. C. the outgroup. D. the ingroup.

C

A/An ________ has been used to estimate that HIV-1 M first spread to humans in the 1930s. A. parsimony analysis B. epidemiological study C. molecular clock D. outgroup comparison

C

According to the latest theories of evolutionary history, which of the following paired groups of organisms are the most closely related? A. bacteria and fungi B. plants and bacteria C. fungi and animals D. protists and archaea

C

According to this figure, during what time frame was there an adaptive radiation of eutherians? A. about 170 million years ago B. about 200 million years ago C. from 100 million years ago to the present D. from 140 to 100 million years ago

C

Below are phylogenetic trees of vertebrates (A) and reptiles (B). Using the data in these models, what might a Tyrannosaurus rex taste like? (A) A. pork chops B. frog legs C. chicken legs D. beef steak

C

Divergence time estimates based on molecular clocks are A. likely to be correct plus or minus a few decades. B. more reliable than divergence dates that are based on analysis of the fossil record. C. best interpreted with caution, since they depend on assumptions that are difficult to test. D. usually worthless since we cannot directly observe divergence times unless we invent a time machine.

C

Higher taxa are like populations, in that some of their species persist and speciate (just as individuals within a population reproduce), whereas other species go extinct (just as individuals die without reproducing). This process, which can help in analyzing evolutionary trends, is referred to as _____. A. natural selection B. exaptation C. species selection D. phylogenetic adaptation

C

If you could travel back in time to examine some of the earliest life-forms, what would you expect to find? Assume you will bring equipment for biochemical analysis! A. DNA used for information storage, polypeptide enzymes catalyzing chemical reactions B. RNA used for information storage, polypeptide enzymes catalyzing chemical reactions C. RNA used for information storage, ribozymes catalyzing chemical reactions D. DNA used for information storage, ribozymes catalyzing chemical reactions

C

If you want to see a dinosaur, it would be best to set the controls of your time machine for the _____. A. Pleistocene epoch, 15,000 years ago B. Carboniferous period, 325 million years ago C. Mesozoic era, 150 million years ago D. Paleozoic era, 400 million years ago

C

Leeches, ticks, mosquitoes, lampreys, and vampire bats all suck blood. Would they form a monophyletic group of close relatives with a recent common ancestor in a phylogenetic tree? A. No, because they have too many shared derived characters that go along with bloodsucking. B. Yes, because they have a shared ancestral trait of bloodsucking. C. No, because their similarities are due to convergent evolution (adaptation to the bloodsucking lifestyle); phylogenetic analysis is based on homologous features, not analogous features. D. Yes, because they are all classified in the same genus.

C

Miller was the first to show that A. the earliest forms of life had an RNA genome. B. eukaryotic life evolved from early prokaryotes. C. amino acids and other organic molecules could have formed under conditions thought to resemble those of early Earth. D. the earliest forms of life were photosynthetic.

C

Over the past 500 million years, there have been ________ mass extinctions, and each time, at least ________ of the species on Earth became extinct. A. twelve; 96% B. two; 25% C. five; 50% D. five; 25%

C

Protocells are _____. A. spheres with lipid membranes that display inheritance B. self-replicating strands of RNA C. spheres with lipid membranes that concentrate solutes and can even carry out simple metabolic reactions if provided with enzymes D. the first life-forms

C

The dog family is Canidae. Some well-known members of the dog family are the domestic dog, Canis familiaris; the coyote, Canis latrans; and the red fox, Vulpes fulva. If this classification represents phylogenetic relationships among the three species, we can conclude that the people who gave these animals these names concluded that __________. A. domestic dogs and coyotes have a different ecological niche than foxes B. foxes are more closely related to dogs than they are to coyotes C. the common ancestor of coyotes and domestic dogs is more recent than the common ancestor of foxes and domestic dogs D. domestic dogs evolved from coyotes

C

The earliest discovered fossils are of ________ dating back to ________ years ago. A. fish; 600 million B. single-celled eukaryotes; 4.5 billion C. prokaryotes; 3.5 billion D. algae; 1 billion

C

The figure below shows locations of modern or fossil lungfish. Their worldwide distribution indicates that _____. A. lungfish have dispersed widely since they originated on Africa in the mid-Cenozoic B. lungfish can tolerate Arctic climates C. lungfish predate the breakup of Pangaea, and thus are at least 250 million years old as a group D. lungfish fossils are not found on the same continents where living lungfish are found

C

The first organisms on Earth were very small, but now when you look around you see many large organisms. Which of the following is the best explanation for this observation? A. Organisms got larger because they needed to be larger in order to use resources more efficiently. B. Evolution tends toward larger and larger organisms. C. There were many steps necessary to go from small cells to large organisms. D. The goal of evolution is to produce the largest organisms possible.

C

What are some of the special strengths of molecular systematics? A. It is based on shared derived characters. B. It can predict traits likely to appear in fossils, and it employs the parsimony principle. C. It allows study of relationships among very closely or very distantly related taxa, and it can often provide estimates of the time in years since taxa diverged. D. It allows ordering of events by comparing taxa within an ingroup to an outgroup that represents their common ancestor.

C

What was the probable role of oxygen gas in the early stages of life's appearance on Earth? A. Cellular respiration, which depends on oxygen availability, provided abundant energy to the first life-forms. B. 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. D. Oxygen promoted the formation of complex organic molecules through physical processes.

C

Which correctly orders the likely steps in the origin of life from nonlife early in Earth's history, from earliest to most recent? A. formation of protocells; abiotic synthesis of small organic molecules; formation of proteins and nucleic acids; origin of self-replicating molecules of inheritance B. formation of protocells; origin of self-replicating molecules of inheritance; abiotic synthesis of small organic molecules; formation of proteins and nucleic acids C. abiotic synthesis of small organic molecules; formation of proteins and nucleic acids; formation of protocells; origin of self-replicating molecules of inheritance D. abiotic synthesis of small organic molecules; formation of proteins and nucleic acids; origin of self-replicating molecules of inheritance; formation of protocells

C

Which of the following generalizations about extinction is FALSE? A. Following a mass extinction event, some surviving taxa may undergo an explosive increase in diversity. B. Extinctions occur regularly, but there are occasional periods in which huge numbers of species become extinct in a relatively short time. C. Mass extinctions probably won't occur in the future because life has become better adapted due to previous mass extinctions. D. Climate change, continental drift, volcanic activity, and asteroid impacts are some of the factors that may have caused past mass extinctions.

C

Which of the following methods to establish phylogenetic relationships among organisms has been developed most recently? A. comparing physiology (the functioning of structures and systems) B. comparing morphology (shape and structure) C. comparing molecular features (such as gene sequences, amino acid sequences) D. comparing embryonic development

C

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, photosynthesis, first eukaryotes, colonization of land by plants and fungi D. first prokaryotes, first eukaryotes, photosynthesis, colonization of land by plants and fungi

C

Which of the following statements regarding genetics is false? A. About 99% of the genes of humans and mice are related by descent from a common ancestor. B. Gene duplication helps to explain how mammals can detect and discriminate among such a wide range of odors. C. In keeping with our greater complexity, the human genome has about 100 times more genes than that of yeast. D. The more recently two species have branched from a common ancestor, the more similar we expect their DNA sequences to be.

C

Which of the following would cast doubt on the asteroid-impact hypothesis for the extinction of the dinosaurs? A. determining that birds are descended from extinct dinosaurs B. finding a crater and associated iridium layer that are 200 million years old C. finding abundant fossil dinosaur bones in strata above (younger than) the 65-million-year-old iridium layer D. finding abundant fossil dinosaur bones in strata below (older than) the 65-million-year-old iridium layer

C

Which of the following would violate the assumptions of the molecular clock? A. comparison of genes for homologous structures across many species B. assuming that organisms in competitive environments have the same rate of mutation as those in noncompetitive environments C. comparison of genes of a species that lives deep in the ocean with relatives that live on the surface and are exposed to strong mutation-inducing ultraviolet radiation D. comparison of many genes in many species of insects that undergo metamorphosis

C

________ and ________ mean the same thing. A. Parsimony; analogy B. Derived; ancestral C. Clade; monophyletic taxon D. Clade; parsimony

C

________ makes it possible to trace phylogenies among microbial groups for which there is no fossil record. A. Horizontal gene transfer B. Comparison to vertebrate outgroups C. Molecular systematics D. Convergent evolution

C

Miller-type experiments have shown that A. given the conditions of early Earth, the formation of life would still require additional materials from meteorites and asteroids. B. simple cells could be produced in the laboratory using a "soup" of small organic molecules. C. living cells could survive in primitive Earth's atmosphere. D. complex organic molecules can be produced by physical processes from inorganic components.

D

According to this figure, if a species were found only in Laurasia 135 million years ago, on which modern continents would its descendants most likely be found today? A. Europe and Asia only B. North America only C. Africa and South America D. North America, Europe, and Asia

D

An event that marked the dividing line between the Mesozoic and Cenozoic eras was the _____. A. origin of soft-bodied animals in the world's oceans B. diversification of the dinosaurs C. origin of tetrapods (early amphibians) D. extinction of the dinosaurs

D

An example of a pair of organisms that have undergone convergent evolution is _____. A. birds and crocodiles B. humans and chimpanzees C. axolotls and related salamanders D. Australian "moles" (marsupials) and North American moles (placental mammals)

D

Cave-dwelling catfish and cave-dwelling salamanders share striking similarities: Both organisms lack pigmentation, and their eyes are reduced or absent. The most recent common ancestor to these organisms had normal pigmentation and fully developed eyes. The similarities between cave catfish and cave salamanders are an example of A. homology. B. convergent homology. C. exaptation. D. analogy (convergent evolution).

D

Feathers are an example of a/an ________; they originally evolved ________. A. homology; for flight B. exaptation; in anticipation of future use in the development of flight C. adaptation; for some other function and only later became adapted for flight D. exaptation; for some other function and only later became adapted for flight

D

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 must have independently colonized each of the landmasses from a third location within the past 45 million years. B. The group's ancestors were definitely present on the original landmass. C. The group's ancestors cannot have been present on the original landmass. D. 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

Geologists have evidence that over the past 1.5 billion years, A. Earth's landmasses have moved about extensively but have remained separate. B. Earth's landmasses have been entirely submerged in water on three occasions. C. Earth's continents have remained essentially in their current shape and positions. D. Earth's landmasses have joined into a single continent and split back apart again on three occasions.

D

How do scientists calibrate a molecular clock for a group of organisms with known nucleotide sequences? A. They measure protein differences. Evolutionary rates in proteins are well-known and can be used to check results obtained using nucleotide sequences. B. They use radioactive isotopes to measure the age of DNA material directly. C. They analyze fossilized DNA of known age and compare its nucleotide sequences to modern DNA sequences. D. They graph the number of nucleotide differences against the dates of evolutionary branch points known from the fossil record.

D

In 1865, a biologist, St. George Jackson Mivart, constructed an evolutionary tree of existing primate species with many branches based on analysis of spinal columns. But to his dismay, another tree based on limb comparison was quite different. Which of the following analyses would be best to include today to determine which tree is more accurate? A. examination of evolutionary trees constructed by others. B. comparison of genes that control development C. comparison of eyes of primates D. comparison of DNA sequences of primates

D

In mammals, the presence of four limbs is ________, and hair is ________. A. a shared derived character; a shared ancestral character that places mammals in the tetrapod clade B. monophyletic; parsimonious C. a homologous feature; an analogous feature D. a shared ancestral character; a shared derived character unique to mammals

D

Molecular clocks are __________. A. used to confirm or correct the divergence dates documented in the fossil record B. superior to other methods of reconstructing the past because they are based on high-tech, molecular data C. isotopes that decay to produce other isotopes at a constant rate in buried samples, allowing precise estimates of the ages of fossils D. one of several ways to estimate divergence times between taxa, by comparing their gene sequences and assuming a constant rate of evolution over time

D

Molecular data can be used to assess relationships among the major groups of living organisms whose common ancestors lived millions or billions of years ago. Similar techniques can be used to assess relationships among populations within a species. How can molecular techniques be useful for such varied comparisons? A. Studying the relationships among different populations of a single species can be just as effective as studying the relationships of major biological groups if you look at a lot more genes. B. The relationships between very different groups such as bacteria and whales are assessed using mtDNA sequences, whereas rRNA sequences are used for very closely related groups. C. The same data can be used for any comparison with equal efficiency. D. Faster-evolving gene sequences provide better data for comparisons among close relatives, whereas very slowly evolving sequences work best for distantly related taxa.

D

The 14C:12C ratio can be used to date fossils that are up to approximately how old? A. 7 million years B. 7,500 years C. 100 million years D. 75,000 years

D

The Himalayas are an example of a mountain range that formed as a result of A. the buildup of sediments and conversion to rock. B. volcanic eruptions. C. the separation of two continental plates. D. the collision of two continental plates.

D

The first fossil of Archaeopteryx, which lived about 150 million years ago, was found in the Solnhofen Quarry in Germany. Archaeopteryx has an interesting collection of characters that led to the hypothesis that it represented an evolutionary transition between modern-day birds and small bipedal dinosaurs. The fossil reveals the imprint of feathers, which connect Archaeopteryx to birds, although they do not present direct evidence of flight. Unlike birds, however, Archaeopteryx was shown by the fossil record to have had teeth, functional claws on the wings that may have been used for climbing trees or holding prey, and a long, bony tail. Birds have a fused collarbone, which was found in Archaeopteryx as well. However, the structure of the sternum differed between the two. In birds, the sternum is keeled (raised and slightly concave); the keel of the sternum serves as an attachment site for the flight muscles. Archaeopteryx had a flat sternum, similar to that found in reptiles. If you were constructing a phylogenetic tree for the evolution of birds, which characters found in Archaeopteryx might provide evidence that birds and dinosaurs had a common ancestor? A. feathers, wings, wishbone B. teeth, feathers, keeled sternum C. keeled sternum, claws, long forelimbs D. teeth, flat sternum, claws

D

This figure shows the hierarchy of classification of the cow, Bos primigenius. Bos primigenius, the name of the cow, represents A. the class and phylum names, which go in boxes H and I, respectively. B. the class and kingdom names, which go in boxes H and I, respectively. C. the domain and kingdom names, which go in boxes A and B, respectively. D. the genus and species names, which go in boxes A and B, respectively.

D

Which best summarizes the idea of adaptive evolution? A. Adaptive evolution is entirely a matter of chance, and therefore evolutionary trends will never occur except within individual species. B. Adaptive evolution is a process of constant improvement that eventually leads to perfection. C. Adaptive evolution produces clear trends in which all of the species in a group evolve to have similar adaptations at similar rates. D. Adaptive evolution occurs as populations interact with changing local environments. Even a long-term trend can reverse itself if the environment changes dramatically.

D

Which of the following lines of evidence suggests that lungfishes evolved while Pangaea was intact? A. Lungfishes are restricted to Australia and neighboring islands. B. Modern lungfishes on different continents show similar patterns of behavior. C. Lungfishes are found today in Africa, Australia, and South America. D. Fossil lungfishes have been found on every continent except Antarctica.

D

Which of the following options lists taxonomic categories in the correct order from most specific to most general? A. genus, family, class, order, phylum B. family, genus, order, phylum, class C. family, genus, class, order, phylum D. genus, family, order, class, phylum

D

Which of the following was virtually absent from the atmosphere at the time life is thought to have originated? A. water (H2O) B. carbon dioxide (CO2) C. methane (CH4) D. oxygen (O2)

D

Why did mammals experience an increase in diversity shortly after the Cretaceous? A. Aquatic mammals thrived in the low coastal areas formed because of continental drift. B. The mammals finally evolved to be strong enough to fight and out-compete the dinosaurs. C. Mammals thrived on iridium, which can be used as an energy source by mammals but not dinosaurs. D. Mammals diversified to take advantage of ecological roles that were previously filled by the dinosaurs.

D

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. approximately 75,000 years ago B. at least 25,000 years ago C. 5,730 years ago D. almost 12,000 years ago

D