Mastering Biology Chapter 13: EXAM #1

The population of American bison used to number in the millions of animals. Hunting and other problems greatly decreased the number of bison to about 1,000 animals. But today, the numbers are recovering to estimates of more than 200,000 animals. This crash in the population of bison and recent recovery is a good example of _____. A). genetic drift B). the founder effect C). the bottleneck effect D). gene flow E). stabilizing selection

C). The bottleneck effect

Which one of the following was an assumption of Charles Darwin's theory of natural selection? A). Organisms are similar in many ways. B). Traits are inherited as discrete particles. C). Earth is very young. D). Organisms cooperate for limited resources. E). Populations produce more offspring than their environment can support.

E). Populations produce more offspring than their environment can support.

Which of the following is the study of the geographic distribution of species on Earth? A). comparative anatomy B). microevolution C). comparative embryology D). biogeography E). paleontology

D). Biogeography

The evolution of populations due to chance is A). genetic variation. B). natural selection. C). has more effect in large populations than in small populations. D). genetic drift. E). gene flow.

D). Genetic drift

As proposed by Darwin, what sorts of traits are favored by natural selection? A). Any traits that are produced by mutation and can be inherited. B). Traits that reduce the number of offspring an individual produces, thus helping to reduce the struggle for existence in the next generation. C). Traits that reduce the mutation rate and cut down on unnecessary variation within populations. D). Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

D). Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

When they were first sold, aerosol insecticides were highly effective in killing flies and mosquitoes. Today, some 30 years later, a much smaller proportion of these insects die when sprayed. The reason fewer insects are being killed is that __________. A). mosquitoes are deliberately adapting themselves to this man-made change in the environment B). the original spraying has caused a permanent mutation, giving the insects genetic resistance to the spray C). mosquitoes that survive spraying develop an immunity to the insecticide D). many mosquitoes today are descendants of mosquitoes with insecticide-resistant characteristics E). over time, evolution produces stronger insects

D). Many mosquitos today are descendants of mosquitos with insecticide-resistant characteristics.

"Differential success in reproduction" is just another way of saying _____. A). variation B). genetic drift C). recombination D). natural selection E). mutation

D). Natural selection

The smallest unit that can evolve is a _____. A). genotype B). species C). gene D). population E). morph

D). Population

According to island biogeography, what is the relationship between an island's distance from the mainland and the number of species present on the island? A) There is no relationship between the distance from the mainland and the number of species found on an island. B) The farther an island is from the mainland, the larger the number of species found on the island. C) The closer an island is to the mainland, the fewer the number of species found on the island. D) The closer an island is to the mainland, the fewer the number of species found on the island; and the farther an island is from the mainland, the larger the number of species found on the island. E) The farther an island is from the mainland, the fewer the number of species found on the island.

E) The farther an island is from the mainland, the fewer the number of species found on the island. Increasing the distance from the mainland increases the difficulty of colonizers reaching the island; thus, the greater the distance, the fewer the number of species on the island.

Most polyploid plants arise as a result of _____. A) self-fertilization B) a mutation of gamete formation C) meiosis D) mitosis E) hybridization

E) hybridization most polyploid plants are the results of the hybridization of two different parental species.

Which of these terms applies to an organism with extra sets of chromosomes? A) monosomy B) haploid C) trisomy D) polyploid E) diploid

E) polyploid polyploid individuals have more than two complete sets of chromosomes.

Humans are diploid and have 46 chromosomes (or two sets). How many sets of chromosomes are found in each human gamete? A) 1 B) 2 C) 3 D) 4 E) 5

A) 1 Meiosis cuts the number of chromosomal sets in half.

Self-replicating molecules are thought to have appeared about: A) 4 billion years ago B) 10 million years ago C) 1 billion years ago D) 40 million years ago

A) 4 billion years ago Life on Earth began between 3.5 and 4 billion years ago with the origin of self-replicating molecules.

According to a recent survey of many studies, an average plant or animal lineage might produce a new species approximately once every _____. A) 5 million years B) 50 years C) 5,000 years D) 500 years

A) 5 million years This is a fairly typical rate of speciation for plant and animal groups— the average value was once every 6.5 million years.

Which of the following statements best describes how the process of natural selection works? A) Better-adapted individuals will leave behind more offspring to carry on their genes, producing a dynamic "fit" between a population and its changing environment. B) Beneficial mutations will arise in response to a new environment. C) Natural selection will lead to increasing population size over time. D) Only the strongest survive.

A) Better-adapted individuals will leave behind more offspring to carry on their genes, producing a dynamic "fit" between a population and its changing environment. Natural selection is differential reproductive success, with the more fit individuals contributing disproportionately more offspring to the next generation than do less fit individuals. It is contingent on current, local conditions.

Scientists have found as many as 500 species of fish in the African Lake Victoria. What can account for this high level of diversity in a single habitat? A) Lake Victoria has a variety of environments such as rocky shores and muddy bottoms; this environment heterogeneity promotes speciation. B) Lake Victoria is a very ancient lake; therefore, there has been more time for a variety of species to evolve. C) A typical value of diversity for a lake the size of Lake Victoria is 500 fish species. D) Lake Victoria is located near the equator; therefore, it has great biodiversity, like the rainforests in South America.

A) Lake Victoria has a variety of environments such as rocky shores and muddy bottoms; this environment heterogeneity promotes speciation. A diversity of environments encourages speciation as organisms become more adapted to each particular niche.

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) over 3.5 billion years ago; over 1.5 billion years ago; 2 billion years ago C) about 350 million years ago; 60 million years ago; 50 million years ago about 35 billion years ago; 6 billion years ago; 5 billion years ago

A) at least 3.5 billion years ago; 600 million years ago; 480 million years ago

Genetic drift is _____. A) more likely to have an impact on small populations B) the mechanism by which new alleles originate C) an important microevolutionary mechanism in large populations D) adaptive

A) more likely to have an impact on small populations

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

A) oxygen (O2) Free oxygen (not bound to another element) was in very short supply.

The first tetrapods (four-legged animals) were amphibians, which evolved from a specialized group of lobed-fin fish. An unusual fossilized animal (named Tiktaalik) was recently found; this animal possessed a mixture of fish and amphibian characteristics. What is the term used to describe such an intermediate organism? A) transitional form B) vestigial C) mutant D) homologous

A) transitional form Transitional forms represent a link between ancestral and descendant groups; they possess features of both groups.

In a population with brown and green alleles for color, genetic drift A). has more effect on the evolution of a small population. B). has more effect on the evolution of a large population. C). always increases the frequency of brown alleles in the population. D). causes populations to become better adapted to their environments. E). occurs when individuals move into or out of a population, changing the allele frequencies in the population.

A). Has more effect on the evolution of a small population.

Which one of the following statements most closely agrees with the theory of evolution by means of natural selection, as put forth by Darwin? A). Organisms better adapted to their immediate environment are most likely to survive and reproduce. B). Organisms deliberately evolve the structures they need to survive. C). Only the best-adapted organisms will survive. D). Humans arose from chimpanzees. E). Organisms mutate under unfavorable conditions to become better adapted.

A). Organisms better adapted to their immediate environment are most likely to survive and reproduce.

Which of these events occurred earliest in the history of Earth? A)formation of oxygen B) first humans C) evolution of land plants, fungi, and land animals D) origin of eukaryotes E) origin of multicellularity

A)formation of oxygen

The number of species on an island remains relatively constant when _____. A) the rate of successful colonization is less than the extinction rate B) the rate of successful colonization equals the extinction rate C) the rate of successful colonization is greater than the extinction rate D) none of these occur E) species richness increases

B) the rate of successful colonization equals the extinction rate At this point the number of successful introductions to an island equals the number of extinctions, and thus the total number of species remains unchanged.

Humans are diploid and have 46 chromosomes. How many chromosomes are found in each human gamete? A) 12 B) 23 C) 36 D) 45 E) 92

B) 23 23 is one half of 46

In which of the following situations is adaptive radiation least likely to occur? A) A species has flexible morphological structures that lend themselves to specialization. B) A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment. C) The dominant organisms in an area become extinct. D) A new island chain forms far from shore and is reached by a few groups of long-distance colonists.

B) A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment. These conditions would reduce the likelihood of adaptive radiation

What is the relationship between colonizing success and the number of species already established on an island? A) As the number of established species on an island decreases, colonizing success also decreases; and as the number of established species on an island increases, colonizing success also increases. B) As the number of established species on an island increases, colonizing success also decreases. C) As the number of established species on an island decreases, colonizing success also decreases. D) As the number of established species on an island increases, colonizing success also increases. E) There is no relationship between the number of established species on an island and colonizing success.

B) As the number of established species on an island increases, colonizing success also decreases. As the number of established species on an island increases, there is likely to be a concomitant increase in the intensity of competition and predation, which make colonization more difficult.

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) Fossil lungfishes have been found on every continent except Antarctica. C) Lungfishes are found today in Africa, Australia, and South America. D) Lungfishes are restricted to Australia and neighboring islands

B) Fossil lungfishes have been found on every continent except Antarctica.

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) nothing much happened. This confirmed that physical processes cannot produce complex molecules B) 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 C) cell-like structures (spherical lipid membranes) formed. This finding helped scientists model how the first cells arose new life-forms arose in the vessel. D) This clearly demonstrated that life can arise from non-life in the proper conditions

B) 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 Miller's findings have since been extended, and new experiments have been designed to simulate other processes in the early evolution of life.

Which of these events occurred during the Paleozoic? A) origin of Earth B) colonization of land by plants C) origin of eukaryotes D) origin of multicellularity E) first humans

B) colonization of land by plants

Which of these events occurred most recently in the history of Earth? A)formation of oxygen B) first humans C) evolution of land plants, fungi, and land animals D) origin of eukaryotes E) origin of multicellularity

B) first humans

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

B) life must have arisen quite a bit earlier, perhaps 3.9 billion years ago The photosynthetic cyanobacteria that produced the stromatolites were probably preceded by simpler non-photosynthetic life-forms, and therefore an even earlier period of prokaryote evolution.

For which of the following groups would the biological definition of species be useful? A) asexually reproducing plant and animal species that live in the present B) oaks and other sexually reproducing, extant (currently living) trees C) fossil bacteria, which are known to have reproduced asexually D) fossil dinosaurs, which are known to have reproduced sexually

B) oaks and other sexually reproducing, extant (currently living) trees

Scientists estimate that _____% of plant species are polyploids, mostly generated through _____. A) 50 ... tetraploids arising from a single diploid parent species B) over 75 ... hybridization between two species C) less than 10 ... hybridization between two species D) 25 ... hybridization between two species

B) over 75 ... hybridization between two species About 80% of plant species may have originated through polyploidy, mostly through complex processes of hybridization as in the wheat example.

New branches form on the tree of life through the process of __________. A) microevolution B) speciation C) genetic drift D) natural selection

B) speciation

Two species of clams inhabit the same marine habitat along the Atlantic coast. One releases gametes into the water in early spring, and the second species releases gametes into the water in late summer. Which type of reproductive barrier is at work between these species? A) habitat isolation B) temporal isolation C) gametic isolation D) reduced hybrid viability

B) temporal isolation Fertilization will not occur if the gametes are released at different times.

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) the exact makeup of the atmosphere on the early Earth D) that they could build macromolecules (especially functional proteins) in the absence of living organisms

B) that organic molecules can be made from inorganic building blocks in the absence of living organisms They were not attempting to replicate the conditions of the early Earth or generate life from nonlife, just to help fill in one gap in scenarios about the origins of life on a prebiotic Earth.

Speciation is likely to occur between a parent population and a population that has become allopatric if _____. A) both populations are large and exhibit a sufficient diversity of alleles B) the allopatric population is small and is isolated from the parent population by a formidable barrier to dispersal C) there is a lot of gene flow between the two populations D) it is in a similar environment to the "parent" population

B) the allopatric population is small and is isolated from the parent population by a formidable barrier to dispersal This promotes rapid microevolution in the small splinter population and prevents gene flow between the groups, which makes it more likely that a reproductive barrier will arise.

Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection? A). Green beetles migrate out of the population. B). Green beetles leave more offspring than brown beetles because they are better at finding food. C). A storm kills more green beetles than brown beetles by chance. D). Green beetles migrate out of the population, and brown beetles migrate into the population. E). Green beetles and brown beetles always leave the same number of offspring.

B). Green beetles leave more offspring than brown beetles because they are better at finding food.

A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are individuals with other characteristics is called _____. A). evolution B). natural selection C). descent with modification D). evolutionary adaptation E). homology

B). Natural selection.

In a population of bears, which is most likely to be considered to have the greatest Darwinian fitness? A). the bear having the largest number of mutations B). the bear that leaves the most descendants C). the bear that blends in with its environment the best D). the biggest bear E). the strongest, fiercest bear

B). The bear that leaves the most descendants.

Imagine that a new population of humans is established on a new planet from ten randomly selected people in your biology class. Over thousands of years, the descendants of those ten people reproduce and prosper, but do not reflect well the diversity of humans on Earth. This change in the diversity of people on the new planet is an example of _____. A). genetic drift B). the founder effect C). gene flow D). the bottleneck effect E). stabilizing selection

B). The founder effect.

Which of the following is a requirement for natural selection? A). nonheritable traits B). variation in individuals C). low numbers of individuals D). a long period of time E). greater numbers of offspring from those that do not survive

B). Variation in individuals

Which population would be most likely to undergo relatively rapid allopatric speciation? A) A population of flowering plants lives along the shore of a pond about one kilometer from the nearest neighboring population. Hummingbirds regularly fly back and forth across this distance and transport pollen between the two populations. B) A group of birds develops a unique set of mating preferences so that they are unlikely to mate with other birds of the same species in the same geographic area. C) A group of wild horses is transported from Wyoming to a small desert island, previously without horses, off the coast of California. No additional horses reach the island thereafter. D) A population of snakes becomes separated from other populations on a very large island that is formed by rising sea levels. Occasionally, a snake or two swims from the mainland to the island or from the island to the mainland.

C) A group of wild horses is transported from Wyoming to a small desert island, previously without horses, off the coast of California. No additional horses reach the island thereafter.

Scientists have warned doctors of the danger of their increasing use of antibiotics (for instance, penicillin) for treating minor illnesses. They are concerned because _____. A). the drugs are not meant to treat minor illnesses and have numerous side effects B). humans will become tolerant to the effects of drugs C). strains of microorganisms that are resistant to these drugs will increase D). the drugs will be metabolized more quickly by our bodies, decreasing their effectiveness E). excessive use of these drugs leads to a diminished sensitivity to them

C). Strains of microorganisms that are resistant to these drugs will increase.

Why was Darwin's acceptance of an ancient, continuously changing Earth so important in his development of his ideas about evolution? A) Darwin hypothesized that as Earth changed, a divine force replaced the existing species with new species that were perfectly suited to the new environment. B) He had to accept that Earth could change in order to also accept that organisms can change. C) Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats. D) Darwin hypothesized that as Earth changed due to volcanic eruptions, new species would appear from deep within the Earth.

C) Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats. Darwin recognized that descendants of a common ancestor adapted to a diversity of habitats through natural selection. To produce current life-forms, this process required a great deal of time within a dynamic Earth environment.

Which of the following statements about reproductive barriers and speciation is true? A) Reproductive barriers can arise in the absence of geographic isolation, but the process of speciation would be slow and take many generations. B) Reproductive barriers can arise only when populations are geographically separated. C) Speciation can occur with even a single gene mutation if that mutation involves reproductive barriers. D) Populations can split into separate species even in the absence of reproductive barriers.

C) Speciation can occur with even a single gene mutation if that mutation involves reproductive barriers. Consider the example of the monkey flower species in the Sierra Nevada. A single gene controls flower color. Changes in flower color can affect pollinator choice and different pollinators can maintain reproductive isolation between species.

Why is the morphological species concept still used to define and describe species? A) If two organisms look alike, they must be the same biological species. B) Physical traits clearly define unique branches on the tree of life. C) This is the most convenient way of identifying species, and it is one of the few ways to identify fossil or asexual species. D) The morphological species concept defines a species in terms of its reproductive behavior, which is the most direct way to identify biological species.

C) This is the most convenient way of identifying species, and it is one of the few ways to identify fossil or asexual species.

A new species can arise in a single generation _____. A) if two forms of a species begin to use different habitats or food resources B) through geographic isolation C) if a change in chromosome number creates a reproductive barrier D) in rapidly evolving species such as insects

C) if a change in chromosome number creates a reproductive barrier This often happens in plants. The most rapid form of speciation by polyploidy occurs when a tetraploid shoot forms, produces diploid gametes, and reproduces by self-pollination.

The most likely location of where ribozymes developed is: A) on land B) in lakes C) in hot-springs D) in the atmosphere

C) in hot-springs Ribozymes are thought to have developed in hot-springs.

If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles, A). this causes the population to evolve due to gene flow. B). the frequency of the brown allele will increase. C). the frequency of the green allele will increase. D). the frequencies of the brown and green alleles will not change. E). this causes the population to evolve due to genetic drift.

C) the frequency of the green allele will increase

Based on the chemical make-up of the first self-replicating molecule, it most closely resembles the structure of certain types of: A) bacteria B) plant cells C) viruses D) animal cells

C) viruses The first self-replicating molecules resembled viruses.

Natural selection is best described as _____. A). a creative force that efficiently develops the best and simplest solutions for all problems in nature B). a forward-looking process that anticipates future problems and designs the necessary tools to solve them through mutation C). a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations D). a completely random and unpredictable process of change, or evolution

C). A filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations.

Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct? A). Natural selection causes the frequency of the brown allele to increase. B). Natural selection causes the frequency of the green allele to increase. C). Gene flow causes the frequency of the brown allele to increase. D). Gene flow causes the frequency of the green allele to increase. E). This is an example of genetic drift.

C). Gene flow causes the frequency of the brown allele to increase.

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

D) likely occurred once or at most a few times about 3.9 billion years ago Spontaneous generation is a theory that states that life arises regularly from nonliving matter. Although it does not occur regularly, it apparently did occur at least once in Earth's history, accounting for the presence of life on Earth today.

Which of the following list of assumptions was part of Charles Darwin's theory of natural selection? A) 1. Earth and its life are very old. 2. Populations produce more offspring than their environment can support. 3. Organisms vary in heritable ways. 4. Mutation rates were higher in the past than they are now. B) 1. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. There is little genetic variability. 4. Organisms vary in heritable ways. C) 1. Organisms vary in heritable ways. 2. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 3. Some traits improve the survival and reproduction of individuals who possess them. 4. Mutations directly cause the changes in species. D) 1. Organisms vary in heritable ways. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 4. Earth and its life are very old.

D) 1. Organisms vary in heritable ways. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 4. Earth and its life are very old.

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

D) 12 to 14 billion years ago.

A particular diploid plant species has 48 chromosomes, or two sets. A mutation occurs and gametes with 48 chromosomes are produced. If self-fertilization occurs, the zygote will have _____ set(s) of chromosomes. A) 1 B) 2 C) 3 D) 4 E) 5

D) 4 If self-fertilization occurs, and two gametes (each having 48 chromosomes) unite, the zygote will have 96 chromosomes ( or 4 sets)

_____ is the process by which haploid gametes form a diploid zygote. A) Embryogenesis B) Meiosis C) Gastrulation D) Fertilization E) Mitosis

D) Fertilization the joining of haploid gametes produces a diploid zygote

Why is a new island more hospitable to colonizers than an older island is? A) The extinction rate is higher on the newer island. B) Predation is less of a factor on older islands. C) Competition is less intense on the newer island. D) The intensity of both competition and predation is less on the newer island. E) Competition is more intense on the newer island.

D) The intensity of both competition and predation is less on the newer island. Immigrants to a newer island are likely to experience lower levels of both competition and predation than are immigrants to older islands.

The following options are all reproductive barriers. Which one is an example of a pre-zygotic barrier in which the two different species do mate? A) Hybrid mules produced by mating donkeys and horses are sterile. B) Two crayfish species cannot interbreed because their genitalia do not engage properly with each other. C) One bird species lives in wetlands, the other in dry forests; hence, they do not encounter each other. D) Two dragonfly species regularly mate, but their gametes are incompatible.

D) Two dragonfly species regularly mate, but their gametes are incompatible.

Which correctly orders the likely steps in the origin of life from non-life 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) abiotic synthesis of small organic molecules; formation of proteins and nucleic acids; origin of self-replicating molecules of inheritance; formation of protocells C) formation of protocells; origin of self-replicating molecules of inheritance; abiotic synthesis of small organic molecules; formation of proteins and nucleic acids D) 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; formation of protocells; origin of self-replicating molecules of inheritance

Mutant tetraploid plants _____. A) are usually sickly B) are able to interbreed with their parents C) have an odd number of chromosomes D) are unable to interbreed with a diploid plant E) unable to self-fertilize

D) are unable to interbreed with a diploid plant This is why polyploidy is a mechanisms of plant speciation.

When a horse and a donkey mate, they produce infertile hybrids called mules. According to the _____ species concept, horses and donkeys are _____. A) ecological ... the same species B) biological ... the same species C) ecological ... different species D) biological ... different species

D) biological ... different species

The main focus of Charles Darwin's studies was on the gradual process of adaptation within populations. In other words, microevolution occurs by means of natural selection. Although critical to evolution this form of change, __________. A) is the main means by which new species arise B) occurs mainly in small, isolated populations C) explains all important forms of evolutionary change D) cannot account by itself for the increase in species diversity over time

D) cannot account by itself for the increase in species diversity over time

Microevolution is _____. A) dramatic changes that take place over long periods of time B) evolution on a molecular level C) speciation D) changes in the gene pool of a population from one generation to the next

D) changes in the gene pool of a population from one generation to the next

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.

A population is __________. A). the number of humans per unit area B). the number of organisms in a particular habitat C). all living organisms on Earth D). a group of individuals of the same species occupying a given area E). organisms of different species that live together

D). A group of individuals of the same species occupying a given area.

What is punctuated equilibrium?

Punctuated equilibrium involves the rapid appearance of new species; such events are separated by long periods of little change in species' traits.