bio 102

Self replicating

(Cond. necessary for life) _____ _______ molecules subject to error by mutation.

Membrane

(Cond. necessary for life) _________ (cellular integrity, isolation from extracellular environment.

Heterotrophic

(Origin of photo.) First cell were ________.

Anaerobic

(Origin of photo.) Metabolism was _________.

Suppose that in a population of 1400, 125 individuals are homozygous for allele A7 and 350 are heterozygous for the allele. The frequency of the A7 allele would be _______.

0.25

If the frequency of one allele at a locus with two alleles is 0.73, the frequency of the other allele must be _______.

0.27

Under Hardy-Weinberg equilibrium, if the frequency of one allele is 0.7 and the frequency of the other allele is 0.3, then _______ of the population should be heterozygotes.

0.42

What are the 3 ways in which genetic differences that accumulate between two diverging lineages may reduce the survival and reproductive rates of hybrid offspring?

1. Low hybrid zygote viability: hybrid zygotes may fail to mature normally. 2. Low hybrid adult viability: Hybrid offspring may have lower survivorship than non-hybrid offspring. 3. Hybrid infertility: hybrids may mature into infertile adults

Suppose the population size of a species of field mice is two million. It has a mutation rate of 2 × 10-9 and its genome size is three billion. The number of new mutations that appear in this species would be about _______.

12 million

Big Bang

13.7 BYA

Solar System

4.6 BYA

It takes 14 days for half of the radioactive isotope phosophorous-32 to decay. After _______ days, one-eighth of the original quantity will be left.

42

Dobzhansky-Muller Model

A population is subdivided and then the two groups evolve independently. In each lineage, new alleles become fixed at different loci. The new alleles at the two loci are incompatible with one another. Genetic incompatibility between the two isolated populations will develop over time.

What is reproductive isolation

A state in which two organisms can no longer exchange genes.

Charles Darwin and _______ independently articulated the concept of natural selection.

Alfred Russel Wallace

3.5-3.8 BYA

Between ________ life evolved after liquid water in oceans

During the most recent geological era, the _______, certain plants such as _______ formed symbioses with nitrogen-fixing bacteria.

Cenozoic; legumes

The mass extinction responsible for the demise of the dinosaurs occurred at the end of the _______ period.

Cretaceous

Famous examples of allopatric speciation

Darwin's finches.

Great evolutionary radiations of corals and shelled squidlike cephalopods occurred during the _______ period.

Devonian

The _______ model explains the evolution of reproductive isolation as a consequence of interactions of alleles at different genetic loci.

Dobzhansky-Muller

Stanley Miller

Experiments demonstrated formation of organic molecules under abiotic conditions.

Species

Groups of organisms that mate with one another

The equation p2 + 2pq + q2 = 1 is known as the _______ equation.

Hardy-Weinberg

RNA

Likely the first biological catalyst.

The Swedish biologist _______ developed the binominal classification system of nomenclature and classified organisms based on a(n) _______ species concept.

Linneaus; morphological

Temporal Isolation

Many organisms have distinct mating seasons. if two closely related species breed at different times of the year they may never have an oppurtunity to hybridize

prezygotic isolating mechanisms

Mechanisms that prevent hybridization from occuring

Early atmosphere

Methane, CO2, ammonia, H2, Water Vapor (H2O)

Early earth

No free oxygen; reducing atmosphere

Heterotrophic

Organisms that cannot synthesize its own food and is dependent on complex organic substances for nutrition.

The Cambrian period is the most ancient period of the _______ era.

Paleozoic

The formation of the giant continent _______ about 275 million years ago caused massive _______ eruptions.

Pangaea; volcanic

The largest mass extinction event occurred at the end of the _______ period, due at least in part to declines in the concentration of _______ in the atmosphere.

Permian; oxygen

cbacteria; 2bya

Photosynthetic _________ began producing O2 approximately ____.

One billion years ago, Earth was in the _______ era.

Precambrian

The current geological period, the _______, is divided into two epochs: the _______ and the Holocene.

Quaternary; Pleistocene

Ribozyme

RNA that catalyzes reactions.

Stromatolites

Rock made of banded domes of sediment in which are found the most ancient forms of life: prokaryotes dating back as far as 3.5 billion years.

Protobionts

Simple membrane-like structures; may be protein, CH, or lipid based; look like aggregates of tiny bubbles.

Spontaneously

Spark charge experiment: Amino acids, purines and pyrimidines formed ___________.

Biological species concept

Species are groups of actually or potentially interbreeding natural populations which are re productively isolated from other such groups.

Lineage species concept

The definition of a species as a branch on the tree of life, which has a history that starts at a speciation event and ends either at extinction or at another speciation event.

Speciation

The divergence of biological lineages and the emergence of reproductive isolation between lineages.

4.5 BYA

The earth is ______

Sympatric speciation

The formation of new species in populations that live in the same geographic area

The evolution of Reproductive Isolation

The most important factor in the divergence of sexually reproducing lineages from one another.

Evolutionary radiation

The rapid proliferation of a large number of descendant species from a single ancestor species

Gametic isolation

The sperm of one species may not attach to the eggs of another species because the eggs do not release the appropriate attractive chemicals, or the sperm may be unable to penetrate the egg because the two gametes are chemically incompatible.

Charles Darwin was influenced by the ideas of the economist _______, who observed that unchecked human population growth leads to famine.

Thomas Malthus

The first period of the Mesozoic, the _______, saw the breakup of the supercontinent _______.

Triassic; Pangaea

Adaptive radiation

When a rapid proliferation of species results in an array of species that live in a variety of environments and differ in the characteristics they use to exploit those environments.

DNA

_____ replaced RNA as hereditary molecule.

Protein

_______ enzymes eventually became main catalyst.

Morphological species concept

a construct that assumes that a species comprises individuals that "look alike" and that individuals that do not look alike belong to different species.

Define hybrid zone

a region in which members of different species meet and mate, producing at least some offspring of mixed ancestry

Independent evolutionary lineage

a separate branch on the tree of life

Evolutionary radiations often occur when...

a species colonizes a new area

Following a flood, migration from neighboring populations alters genotypic frequencies of a population of river-bottom midges. Assuming that the conditions for Hardy-Weinberg subsequently are met, how many generations of random mating are required to restore the genotypic frequencies to Hardy-Weinberg equilibrium? a. 1 b. 2 c. Between 3 and 10 d. Between 11 and 20 e. More than 20

a. 1

Which of the following is believed to be the dominant mode of speciation among most groups of organisms? a. Allopatric speciation b. Sympatric speciation c. Reinforcement d. Hybrid speciation e. Temporal speciation

a. Allopatric speciation

The first snakes evolved during the _______ period. a. Cretaceous b. Permian c. Triassic d. Devonian e. Cambrian

a. Cretaceous

Which of the following statements is false? a. Darwin focused on the underlying causes of speciation. b. Darwin lacked the tools of modern genetics. c. The title of Darwin's most famous book reflected his recognition of the preeminent importance of the origin of new species in biological science. d. The origin of new species involves the splitting and divergence of a single lineage into distinct species. e. All of the above are true; none is false.

a. Darwin focused on the underlying causes of speciation.

Which of the following is least likely to help maintain genetic variation? a. Directional selection b. The mating advantage of heterozygotes c. Varying environments d. Sexual recombination e. Frequency-dependent selection

a. Directional selection

Which of the following statements about the Hardy-Weinberg equilibrium is true? a. It explains why dominant alleles do not necessarily replace recessive alleles in a population. b. It applies only to populations in which there is gene flow. c. It assumes that populations are small. d. It assumes that individuals prefer to mate with individuals with certain genotypes. e. None of the above

a. It explains why dominant alleles do not necessarily replace recessive alleles in a population.

Which of the following is a benefit of sexual reproduction? a. It generates new combinations of alleles upon which selection can act. b. It breaks up adaptive combinations of genes. c. The division of offspring into separate genders reduces the overall reproductive rate. d. It promotes Muller's ratchet. e. None of the above

a. It generates new combinations of alleles upon which selection can act.

Which of the following statements about genetic drift as an evolutionary factor is true? a. It is more significant in a population with small numbers than in a population with large numbers. b. It is responsible for the selection of mutations. c. It is connected to the movements of alleles between populations of a single species. d. Its strength is proportional to the size of a population: the larger the population, the greater the force. e. Both a and b

a. It is more significant in a population with small numbers than in a population with large numbers.

Which of the following statements about Rhagoletis pomonella is true? a. Larvae learn the odor of the fruit in which they grew up, and they locate such plants for mating and laying their eggs. b. The apple- and hawthorn-feeding types of Rhagoletis can be considered incipient species because they show partial polyploidy. c. The apple- and hawthorn-feeding types of Rhagoletis emerge at approximately the same time. d. All of the above e. None of the above

a. Larvae learn the odor of the fruit in which they grew up, and they locate such plants for mating and laying their eggs.

During the Permian period, all of the continents came together to form one supercontinent known as a. Pangaea. b. Gondwana. c. Laurasia. d. Crinoid. e. Ork.

a. Pangaea.

Which of the following statements about carbon dating is true? a. Radioactive decay of 14C is balanced by its production from neutrons reacting with 14N in the upper atmosphere. b. Dead organisms continue to exchange carbon compounds with the environment. c. Carbon dating can be used to date organisms more than a million years old. d. The half-life of 14C is less than 1,000 years. e. None of the above

a. Radioactive decay of 14C is balanced by its production from neutrons reacting with 14N in the upper atmosphere.

Which of the following statements about the evolution of reproductive isolation is false? a. Reproductive isolation evolves at about the same rate in nearly all groups of organisms. b. Reproductive isolation can gradually evolve in the lab, even if the researchers do not directly select for it. c. Reproductive isolation gradually increases with increasing genetic distance. d. Reproductive isolation is not "all-or-nothing": intermediate levels of reproductive isolation can be found. e. All of the above are true; none is false.

a. Reproductive isolation evolves at about the same rate in nearly all groups of organisms.

What did the experiments by Rice and Salt with fruit flies show? a. Speciation can be studied in the lab. b. The evolution of reproductive isolation requires more than one hundred generations. c. Acetyldehyde can be used to keep flies from being species. d. Both a and b e. Both a and c

a. Speciation can be studied in the lab.

Which of the following modes of selection leads to a reduction in variation but no change in the mean? a. Stabilizing selection b. Directional selection c. Disruptive selection d. Both a and c e. Both b and c

a. Stabilizing selection

Rodents, marsupials, and hoofed animals first appeared in North America during the _______ period. a. Tertiary b. Permian c. Triassic d. Devonian e. Cretaceous

a. Tertiary

The symbiosis between legumes and nitrogen-fixing bacteria began in the a. Tertiary. b. Permian. c. Triassic. d. Devonian. e. Cambrian.

a. Tertiary.

Which of the following statements about the Cambrian is true? a. The Burgess Shale is a Cambrian fossil bed. b. The first multicellular life occurred during the Cambrian. c. The Cambrian marks the end of the Paleozoic era. d. Oxygen concentrations were low during the Cambrian. e. None of the above

a. The Burgess Shale is a Cambrian fossil bed.

Which of the following statements about radioisotope dating is false? a. The isotopes in sedimentary rocks contain reliable information about the dates of their formation. b. Igneous rocks are formed when molten material cools. c. The decay of potassium-40 to argon-40 has been used to date most of the ancient events in the evolution of life. d. Paleomagnetic dating relates the ages of rocks to patterns in Earth's magnetism. e. All of the above are true; none is false.

a. The isotopes in sedimentary rocks contain reliable information about the dates of their formation. b. Igneous rocks are formed when molten material cools.

Which of the following species concepts would have great difficulty with the classification of cryptic species? a. The morphological species concept b. The lineage species concept c. The biological species concept d. Both b and c e. None of the above

a. The morphological species concept

Which of the following statements about sexual selection is true? a. Traits favored by sexual selection are often costly to males. b. Sexual selection operates primarily on survival success. c. Females gain a fitness benefit by choosing males on the basis of traits that can easily be faked. d. Darwin's contemporaries immediately recognized the importance of his ideas about sexual selection. e. Sexual selection applies to the ability of individuals of one sex to compete for access to members of the opposite sex, not to matters of sexual attractiveness.

a. Traits favored by sexual selection are often costly to males.

Which of the following statements is true? a. Two different populations can have the same allele frequency but different genotype frequencies. b. Populations that are polymorphic have only one allele at a locus. c. If an allele is fixed in a population, that population is polymorphic. d. All of the above e. None of the above

a. Two different populations can have the same allele frequency but different genotype frequencies.

The proliferation of a large number of daughter species from a single ancestor is known as a. an evolutionary radiation. b. an evolutionary explosion. c. an adaptive explosion. d. reinforcement. e. Darwin's process.

a. an evolutionary radiation.

The pin/thrum flower polymorphism in primroses a. is an example of nonrandom mating. b. ensures that pollination occurs between individuals of the same genotype. c. alters allele frequencies. d. exists because pollen grains from pin and thrum flowers are deposited on the same parts of the body of insects that visit the flowers. e. is a form of self-fertilization.

a. is an example of nonrandom mating.

isolated lineages will...

accumulate many allele differences at many gene loci.

When reproductive isolation between developing species evolves with the populations being geographically separated, the mode of speciation is called geographic or _______ speciation.

allopatric

Polyploidy can arise from the combining of the chromosomes of two different species. This is known as _______.

allopolyploidy

The species-as-lineage concept...

also accommodates species that reproduce asexually.

Lineage

an ancestor-descendant series of populations followed over time

Polyploidy can result in complete reproductive isolation in two generations...

an important exception to the general rule that speciation is a gradual process.

reinforcement

any event that strengthens the behavior it follows

If the population in the previous question mated randomly and no other evolutionary forces operated, what would be the allele frequencies of their offspring? a. 0.875; 0.125 b. 0.125; 0.875 c. 0.25; 0.75 d. 0.75; 0.25 e. 0.5; 0.5

b. 0.125; 0.875

What would be the allele frequencies (red, followed by black) if a population bottleneck occurred and only four individuals survived: one female red heterozygote and three black males? a. 0.875; 0.125 b. 0.125; 0.875 c. 0.25; 0.75 d. 0.75; 0.25 e. 0.5; 0.5

b. 0.125; 0.875

What would be the expected red and black allele frequencies if 1000 black individuals migrated into the population? a. 0.75 red; 0.25 black b. 0.25 red; 0.75 black c. 0.33 red; 0.67 black d. They would not change because the population would still be in Hardy-Weinberg equilibrium. e. None of the above

b. 0.25 red; 0.75 black

What would be the expected frequencies of the homozygous dominant, heterozygous, and homozygous recessive after 100 generations? a. 0.75; 0.20; 0.05 b. 0.25; 0.5; 0.25 c. All red, because it is the natural color. d. All black, because all red alleles would mutate to black. e. None of the above

b. 0.25; 0.5; 0.25

If a population with two alleles is at Hardy-Weinberg equilibrium and the frequency of one allele is 0.7, what is the heterozygote frequency? a. 0.7 b. 0.42 c. 0.3 d. 0.21 e. Insufficient information is given to answer the question.

b. 0.42

Suppose you have a population of flour beetles with 1000 individuals. Normally the beetles are red; however, this population is polymorphic for a mutant autosomal body color, black, designated by b/b. Red is dominant to black, so B/B and B/b genotypes are red. Assume the population is in Hardy-Weinberg equilibrium, with equal frequencies of the two alleles. What would be the expected frequencies of the red and black phenotypes? a. 0.5 red; 0.5 black b. 0.75 red; 0.25 black c. 0.25 red; 0.75 black d. 0 e. Insufficient information is given to answer the question.

b. 0.75 red; 0.25 black

Which of the following situations is least likely to lead to geographic isolation, hence inhibiting allopatric speciation? a. An eight-lane highway divides a population of snails with limited mobility. b. A narrow, but deep, river divides a population of hummingbirds. c. A narrow, but deep, river divides a population of white-footed mice (not known for their swimming ability). d. A patch of land bisects a river and divides a population of minnows. e. A mountain range divides a population of moths.

b. A narrow, but deep, river divides a population of hummingbirds.

Which of the following statements about polyploidy is true? a. Autopolyploids may be produced when individuals of two different but closely related species hybridize. b. Botanists estimate that 95 percent of fern species are polyploids. c. Autopolyploids are often fertile because each of the chromosomes has a nearly identical partner with which to pair during meiosis. d. Polyploidy is more common in animals than in plants. e. A tetrapoloid individual usually can produce viable offspring by mating with a diploid.

b. Botanists estimate that 95 percent of fern species are polyploids.

In a population of field mice in the Sand Hills of Nebraska, some individuals have lighter coat colors than others. Which of the following would be the most straightforward way to observe whether the lighter coat color is a heritable trait? a. Obtain DNA sequence from the individuals. b. Breed the mice of both colors in the lab and observe the coat colors of their offspring. c. Perform a chemical analysis of the coat hairs. d. Conduct a field experiment to observe whether the lighter mice have a lower risk of predation than the darker mice. e. Compare the number of offspring produced by light- and dark-colored mice.

b. Breed the mice of both colors in the lab and observe the coat colors of their offspring.

In undisturbed sedimentary rock, strata from which period would be immediately below rocks from the Ordovician? a. Devonian b. Cambrian c. Jurassic d. Silurian e. Cretaceous

b. Cambrian

Which of the following geological periods is the most ancient? a. Devonian b. Cambrian c. Jurassic d. Silurian e. Cretaceous

b. Cambrian

Which of the following gases has substantially increased in concentration in the last 200 years? a. Oxygen b. Carbon dioxide c. Nitrogen d. Argon e. Hydrogen

b. Carbon dioxide

Which of the following statements about oxygen and ancient Earth is true? a. The atmosphere of early Earth contained almost as much free oxygen as present-day Earth, but most of this oxygen was lost in the Cambrian. b. Early bacteria generated free oxygen as a by-product of the chemical splitting of water. c. The oxygen-generating cyanobacteria have gone extinct. d. All of the above e. None of the above

b. Early bacteria generated free oxygen as a by-product of the chemical splitting of water.

The biological species concept is most closely associated with which of the following scientists? a. Charles Darwin b. Ernst Mayr c. Margaret Dayhoff d. Alan Templeton e. Carolus Linnaeus

b. Ernst Mayr

Which of the following statements is false? a. The size of cells is constrained by the dictates of physics and chemistry. b. Evolutionary biologists agree about the extent to which the lack of genetic variation constrains the rate and direction of evolution. c. Developmental processes can constrain evolution. d. For an adaptation to evolve, the fitness benefits it confers must exceed the fitness costs it imposes. e. All of the above are true; none is false.

b. Evolutionary biologists agree about the extent to which the lack of genetic variation constrains the rate and direction of evolution.

Which of the following is not a goal of population genetics? a. Explaining the patterns of genetic variation b. Explaining how genotypic information is expressed as phenotypic traits c. Explaining the origins of genotypic variation d. Understanding the mechanisms by which allele frequencies change in populations e. Explaining how genetic variation is maintained

b. Explaining how genotypic information is expressed as phenotypic traits

Based on the experiment in which Drosophila flies were raised at a higher than normal oxygen concentration, which of the following statements is most likely true? a. Fly body size is constrained because there are not enough alleles that increase body size. b. Fly body size is constrained because alleles that increase body size are selected against at normal oxygen levels. c. At normal oxygen concentration levels, fly body size is under strong directional selection. d. Fly body size would likely increase if flies were raised at lower than normal oxygen concentrations. e. Increased oxygen levels appear to have little effect on fly body size, even after many generations.

b. Fly body size is constrained because alleles that increase body size are selected against at normal oxygen levels.

Which of the following is the most likely sequence of events in geographic speciation? a. Geographic barrier, reproductive isolation, genetic divergence b. Geographic barrier, genetic divergence, reproductive isolation c. Genetic divergence, geographic barrier, reproductive isolation d. Genetic divergence, reproductive isolation, geographic barrier e. Reproductive isolation, genetic divergence, geographic barrier

b. Geographic barrier, genetic divergence, reproductive isolation

Which of the following conditions would most likely increase the likelihood of an animal being fossilized? a. Living in an oxygen-rich environment b. Having an exoskeleton c. Living in an area where geological processes often transform rocks d. Both a and b e. None of the above

b. Having an exoskeleton

Which of the following would not be considered an example of a trade-off? a. Brightly colored male guppies are more successful at acquiring mates than other males but are more likely to be killed by predators. b. Humans that carry the e4 allele for the Apo-E gene are at greater risk than individuals without this allele for acquiring Alzheimer's and coronary heart disease. c. Rats that are resistant to the poison warfarin have an increased need for vitamin K. d. All of the above e. None of the above

b. Humans that carry the e4 allele for the Apo-E gene are at greater risk than individuals without this allele for acquiring Alzheimer's and coronary heart disease.

Which of the following statements is false? a. Darwin's theory of evolution by natural selection was influenced by his experiences as a pigeon breeder. b. Individuals evolve according to Darwin's theory. c. Death rates in nature are usually high. d. Offspring tend to resemble their parents. e. All of the above are true; none is false.

b. Individuals evolve according to Darwin's theory.

Which of the following statements about the neurotoxin tetrodotoxin (TTD) is false? a. It is sequestered in the skin of rough-skinned newts. b. It paralyzes nerves and muscles by blocking potassium channels. c. It is an example of an adaptation. d. It is an example of a chemical defense. e. All of the above are true; none is false.

b. It paralyzes nerves and muscles by blocking potassium channels.

Which of the following is a major limitation of the morphological species concept? a. It requires detailed knowledge of genetics and mating behavior. b. Males and females of a single species do not necessarily look alike. c. It is a very recent concept. d. It is incompatible with the binomial system of classification. e. It cannot be used in field guides.

b. Males and females of a single species do not necessarily look alike.

Which of the following processes results in adaptation? a. Mutation b. Natural selection c. Genetic drift d. Migration e. Nonrandom mating

b. Natural selection

Which of the following is a plausible explanation for the typically slow rates of evolution over the long term? a. Most populations have little genetic variation. b. Natural selection is typically a stabilizing phenomenon. c. Directional selection is commonplace. d. Genetic drift counters the effects of selection, particularly in large populations. e. Mutation rates are very high.

b. Natural selection is typically a stabilizing phenomenon.

The artificial selection experiments with bristle number in Drosophila illustrate which of the following generalities? a. In such experiments, it is difficult to obtain individuals with traits that fall outside the range found in the original population. b. Populations often contain considerable genetic variation upon which selection can operate. c. A particular phenotype can be produced by more than one genotype. d. Such experiments usually take thousands of generations to achieve their results. e. Bristle number is a genotype, not a phenotype.

b. Populations often contain considerable genetic variation upon which selection can operate.

The current geological period is the a. Tertiary. b. Quaternary. c. Triassic. d. Devonian. e. Pleistocene.

b. Quaternary.

Which of the following statements is true? a. Earth's magnetic field never changes. b. Radioisotope dating of rocks, combined with fossil analysis, is the most powerful method of determining geological age. c. Geological periods are divided into eras. d. In order to date igneous rocks, geologists search for places where sedimentary rocks have intruded into the bed's igneous rocks. e. All of the above

b. Radioisotope dating of rocks, combined with fossil analysis, is the most powerful method of determining geological age.

Which of the following is the correct ranking with respect to number of species (from highest to lowest) of plants pollinated by wind (Wind), plants pollinated by animals that are generalist pollinators (Generalist), and plants pollinated by animals that are specialist pollinators (Specialist)? a. Wind > Generalist > Specialist b. Specialist > Generalist > Wind c. Generalist > Specialist > Wind d. Specialist > Wind > Generalist e. Generalist > Wind > Specialist

b. Specialist > Generalist > Wind

Which of the following best describes natural selection? a. Chance variations in traits b. The differential survival and reproduction of individuals c. The processes that lead individuals to resemble their parents d. The potential for all species to increase rapidly in number e. The immutability of species

b. The differential survival and reproduction of individuals

Which of the following statements about fitness and natural selection is true? a. The fitness of individuals of a particular phenotype is a function of the probability that such individuals survive, divided by the average number of offspring they produce. b. The fitness of individuals of a particular phenotype is a function of the probability that such individuals survive, multiplied by the average number of offspring they produce. c. Changes in the absolute numbers of offspring necessarily lead to changes in allele frequencies from one generation to the next. d. Both a and b e. Both b and c

b. The fitness of individuals of a particular phenotype is a function of the probability that such individuals survive, multiplied by the average number of offspring they produce.

Which of the following is the most likely reason that we need to develop a new flu vaccine every year? a. The flu virus evolves due to negative selection. b. The flu virus evolves due to positive selection. c. The vaccine evolves due to negative selection. d. Humans evolve from year to year. e. Our immune system degrades over time.

b. The flu virus evolves due to positive selection.

Which of the following is the longest period of time? a. The length of the entire Mesozoic era b. The half-life of 40K c. Five million years d. The half-life of 14C e. The time since the Cambrian explosion

b. The half-life of 40K

Ginkgo trees grow in Asia and North America and thus are divided into two groups that are geographically separated. What aspect of Mayr's framing of the biological species concept classifies these populations as belonging to the same species? a. They are reproductively isolated. b. The two populations are potentially capable of exchanging genes. c. They exchange genes across the Pacific Ocean. d. They have different evolutionary ancestries. e. They have formed a large hybrid zone.

b. The two populations are potentially capable of exchanging genes.

Which of the following statements about the Cambrian is false? a. Arthropods were abundant and diverse during this period. b. There was abundant multicellular terrestrial life. c. Large continents had already formed. d. Oxygen concentrations were approaching current levels. e. All of the above are true; none is false.

b. There was abundant multicellular terrestrial life.

Which of the following statements best explains why the silverswords underwent an adaptive radiation and the tarweeds did not? a. The ancestors of the silverswords had more ecological opportunities. b. There were fewer trees in the areas in which the ancestors of the tarweeds settled. c. Silverswords had a more behaviorally complex mating system, and thus there were more opportunities for the evolution of prezygotic reproductive isolation. d. Stabilizing selection prevented the evolution of reproductive isolation in tarweeds. e. None of the above.

b. There were fewer trees in the areas in which the ancestors of the tarweeds settled.

Which of the following statements about Hawaiian silverswords is true? a. They are genetically diverse. b. They exhibit extraordinary morphological diversity. c. Their opportunities to exploit the "tree" way of life have been preempted. d. They share a very distant common ancestor that currently lives in Asia. e. All of the above

b. They exhibit extraordinary morphological diversity.

During which period did Pangaea begin to separate? a. Cambrian b. Triassic c. Jurassic d. Permian e. Quaternary

b. Triassic

Subpopulations often vary genetically from one another because they a. are subject to stabilizing selection. b. are subject to different selective pressures. c. experience a high rate of gene flow. d. experience different rates of mutation. e. All of the above

b. are subject to different selective pressures.

The Cambrian explosion started _______ the Cambrian and lasted for _______ of years. a. before; tens of thousands b. before; millions c. during; hundreds d. during; tens of thousands e. during; millions

b. before; millions

Darwin published The Origin of Species a. before 1840. b. between 1841 and 1880. c. between 1881 and 1920. d. between 1921 and 1960. e. after 1960.

b. between 1841 and 1880.

Life first evolved on Earth _______ years ago. a. more than 5 billion b. between 3 billion and 5 billion c. between 2 billion and 3 billion d. between 1 billion and 2 billion e. less than 1 billion

b. between 3 billion and 5 billion

The _______ species concept holds that "species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups." a. Darwinian b. biological c. morphological d. Linnaean e. natural populations

b. biological

With respect to changes in climate over the course of life on Earth, we are currently living in a _______ period, and the average temperature has _______ over the last 100 years. a. warm; increased b. cool; increased c. warm; decreased d. cool; decreased e. warm; been relatively constant

b. cool; increased

The sperm of one species of sea urchin is chemically incompatible with the eggs of a closely related species. This type of reproductive isolating barrier is called a. postzygotic isolation. b. gametic isolation. c. low hybrid zygote viability. d. temporal isolation. e. behavioral isolation

b. gametic isolation.

Studies of the columbines Aquilegia formosa and A. pubescens illustrate that a. hybrids rarely form between these species because the two species are not interfertile. b. hawkmoths prefer one species over the other because of differences between the species in the color of light that they emit. c. hawkmoths show equal preference for the two species if the flowers of A. formosa are turned upright. d. All of the above e. None of the above

b. hawkmoths prefer one species over the other because of differences between the species in the color of light that they emit.

In pin flowers, the style is _______ and the stamens are _______. a. long; long b. long; short c. short; long d. short; short e. short; absent

b. long; short

Studies of enzyme genotypes and flight in Colias butterflies showed that a. males that are heterozygous at PGI are always inferior in flight compared to homozygotes. b. males that are heterozygous at PGI have greater mating success than homozygous males because they are able to fly farther in a broad range of temperatures. c. genotypes at PGI do not affect flight ability. d. flight ability and mating success are not correlated. e. flight ability can be explained by Muller's ratchet.

b. males that are heterozygous at PGI have greater mating success than homozygous males because they are able to fly farther in a broad range of temperatures.

The ultimate origin of genetic variation is a. genetic drift. b. mutation. c. natural selection. d. a founder effect. e. nonrandom mating.

b. mutation.

The exchange of allele b1 for b2 at the b locus does not affect the fitness of individuals. These alleles can thus be considered _______ alleles. a. selected b. neutral c. neutered d. Muller's e. deleterious

b. neutral

Rocks that are formed when grains accumulate at the bottom of bodies of water are called _______ rocks a. igneous b. sedimentary c. strata d. tertiary e. deep

b. sedimentary

Rocklike structures formed by the oxygen-generating cyanobacteria are known as a. strata. b. stromatolites. c. igneous. d. lithospheric. e. rift valleys.

b. stromatolites.

All of the plants living at a particular time or place are called a. the biota. b. the flora. c. the fauna. d. the igneous species. e. Gondwana.

b. the flora.

An evolutionary biologist makes decisions about whether to consider different populations of lacewings as separate species based on observations of the individuals with which these lacewings will mate. This biologist is most likely employing the _______ species concept.

biological (reproductive)

Reproductive isolation can evolve as a..

by-product of the genetic changes in the two diverging lineages.

Assuming that there are only two alleles at a given locus, if the frequency of one allele is 0.6, what is the frequency of the other allele? a. -0.6 b. 0 c. 0.4 d. 0.6 e. 1

c. 0.4

In a population of 200 individuals, 72 are homozygous recessive for the character of eye color (cc). One hundred individuals from this population die from a fatal disease. Thirty-six of the survivors are homozygous recessive. In the original population, the frequency of the dominant allele is a. 0.16. b. 0.36. c. 0.40. d. 0.48. e. 0.60.

c. 0.40.

In the new population, the frequency of the dominant allele is a. 0.16. b. 0.36. c. 0.40. d. 0.48. e. 0.60.

c. 0.40.

The half-life of a particular radioactive isotope of element X is 100 years. If you know that 400 years ago a fossil contained 10 mg of this isotope, you would expect to find about _______ in that fossil today. a. 5 mg b. 2.5 mg c. 0.6 mg d. 0.3 mg e. 0.15 mg

c. 0.6 mg

Humans reached North America approximately _______ years ago. a. 500 b. 1,500 c. 15,000 d. 100,000 e. 1 million

c. 15,000

Approximately _______ fossil species have been described. a. 3,000 b. 30,000 c. 150,000 d. 1.7 million e. 10 million

c. 150,000

In a hypothetical population of sawflies, 20 percent of the population is homozygous for allele A and 45 percent is homozygous for allele a. Assuming that A and a are the only alleles at this locus, what percent of the population is heterozygous? a. 10 percent b. 20 percent c. 35 percent d. 45 percent e. Insufficient information is given to answer the question.

c. 35 percent

The Cenozoic era began about _______ years ago. a. 1 million b. 15 million c. 65 million d. 225 million e. 1 billion

c. 65 million

Which of the following statements about the relationship between genotype and phenotype is true? a. A given genotype always produces a specific phenotype. b. Genotypes alone determine all phenotypes. c. A particular phenotype can be produced by more than one genotype. d. Dominance makes the study of the genetic basis of natural selection easy. e. None of the above

c. A particular phenotype can be produced by more than one genotype.

The biological species concept does not apply to which of the following groups of organisms? a. Birds b. Mammals that form monogamous pair bonds c. Asexual fungi. d. Fungi that engage in sexual reproduction e. Cryptic species

c. Asexual fungi.

What is the most likely vegetable to be produced from wild mustard, Brassica oleracea, given continued selection for larger stems and flowers? a. Kale b. Brussels sprouts c. Broccoli d. Cabbage e. Cauliflower

c. Broccoli

Which of the following represents a correct chronological ordering of Earth's geological history, from the most ancient to the most recent period? a. Cambrian, Cretaceous, Devonian, Permian b. Cretaceous, Devonian, Permian, Cambrian c. Cambrian, Devonian, Permian, Cretaceous d. Permian, Cambrian, Cretaceous, Devonian e. Cretaceous, Permian, Devonian, Cambrian

c. Cambrian, Devonian, Permian, Cretaceous

Which of the following would likely lead to an increase in speciation rates? a. Increased dispersal ability b. A shift from animal to wind pollination c. Complex sexually selected behaviors d. A shift from plant-eating to insect-eating e. None of the above

c. Complex sexually selected behaviors

Fishlike amphibians began to occupy land during the a. Cretaceous. b. Cambrian. c. Devonian. d. Silurian. e. Holocene.

c. Devonian.

Which of the following modes of selection arises when individuals at both extremes of the distribution have high fitness? a. Stabilizing selection b. Directional selection c. Disruptive selection d. Both a and b e. Both b and c

c. Disruptive selection

Which of the following was required for sympatric speciation in species like the apple maggot fly? a. Genetic drift b. Stabilizing selection c. Disruptive selection d. Allopatry e. Polyploidy

c. Disruptive selection

Which of the following statements about the Dobzhansky-Muller model of speciation is true? a. It requires a phase in which some individuals are reproductively incompatible with other individuals in the same population. b. It involves a single gene. c. Empirical examples support the model. d. All of the above e. None of the above

c. Empirical examples support the model.

Which of the following is most likely responsible for the low number of inversion types seen in North American populations of Drosophila suboscura? a. Mutation b. Nonrandom mating c. Genetic drift d. Heterozygous advantage e. Sexual selection

c. Genetic drift

Which of the following is not a prezygotic reproductive isolating barrier? a. Behavioral isolation b. Mechanical isolation c. Hybrid infertility d. Temporal isolation e. None of the above

c. Hybrid infertility

Which of the following does the Dobzhansky-Muller model of speciation necessarily require? a. Natural selection b. Reinforcement c. Interaction between alleles at different loci d. Chromosomal rearrangements, particularly centric fusions e. Temporal isolation

c. Interaction between alleles at different loci

Which of the following statements about the Hawaiian Islands is true? a. Fewer than 100 species of insects inhabit the islands. b. More than 100 species of amphibians are native to the islands. c. More than 90 percent of the plant species found in the islands are endemic species. d. There is only one species of land snail inhabiting the islands. e. None of the above

c. More than 90 percent of the plant species found in the islands are endemic species.

If the half-life of a radioactive substance is 600 years, what fraction of the original material is left after 1,800 years? a. One-half b. One-fourth c. One-eighth d. One-sixteenth e. None of the above

c. One-eighth

At the end of which of the following periods did oxygen concentrations decrease from about 30 percent to 15 percent? a. Cambrian b. Cretaceous c. Permian d. Devonian e. None of the above

c. Permian

Which of the following was not known to eighteenth- and nineteenth-century geologists? a. Fossil organisms found in more recent strata resemble modern organisms more than those found in more ancient strata. b. Fossils of similar organisms are found in widely separated places on Earth. c. Radioactivity can be used to determine the age of rocks. d. All of the above e. None of the above

c. Radioactivity can be used to determine the age of rocks.

Drosophila pseudoobscura and D. persimilis are two species of flies that live in the western United States. The geographic range of D. persimilis, which is much smaller than that of D. pseudoobscura, is enclosed within the range of D. pseudoobscura. Findings by Mohamed Noor and others show that D. pseudoobscura taken from areas that overlap with D. persimilis are less likely to mate with D. persimilis than are the D. pseudoobscura flies from populations that do not experience D. persimilis. What is the most likely explanation for these results? a. Temporal isolation b. The Dobzhansky-Muller model c. Reinforcement d. The Darwin effect e. Adaptive radiation

c. Reinforcement

Which of the following statements about Earth's history is true? a. A paleontologist can determine the age of a rock by its appearance alone. b. In all sedimentary rock, the oldest layers lie at the bottom, and successively higher strata are progressively younger. c. Sedimentary rock forms via the accumulation of grains at the bottoms of rivers and other bodies of water. d. The continents have always been where they are today. e. None of the above

c. Sedimentary rock forms via the accumulation of grains at the bottoms of rivers and other bodies of water.

Which of the following statements about Darwin's finches is true? a. They arose from at least three different species from the South American mainland. b. There are more species of Darwin's finches than of Hawaiian Drosophila. c. Several, but not all, of Darwin's finches primarily eat seeds. d. The finches show little differentiation in their beak shape and differ mainly in their size. e. None of the above

c. Several, but not all, of Darwin's finches primarily eat seeds.

Which of the following explanations has not been proposed as an explanation for the existence of sexual reproduction? a. Sexual reproduction facilitates repair of damaged DNA. b. Sexual reproduction promotes the elimination of deleterious mutations. c. Sexual reproduction accelerates Muller's ratchet. d. Sexual reproduction creates a great diversity of genetic combinations that allows populations to adapt to the presence of pathogens. e. None of the above; all of the above explanations have been proposed for the existence of sexual reproduction.

c. Sexual reproduction accelerates Muller's ratchet.

What was Darwin's explanation for the evolution of bright colors and other apparently useless (and potentially deleterious) but conspicuous characters in males of many species? a. Stabilizing selection b. Genetic drift c. Sexual selection d. Disruptive selection e. Gene flow

c. Sexual selection

Vascular plants first appeared during the a. Cambrian. b. Ordovician. c. Silurian. d. Carboniferous. e. Permian.

c. Silurian.

Although Darwin's voyage aboard the HMS Beagle took him around the world, most of his observations on natural history were made on the continent of _______ and its nearby islands. a. Europe b. North America c. South America d. Asia e. Africa

c. South America

Which of the following principles of Darwin's theory were guided by his reading of the economist Thomas Malthus? a. The world is old. b. Individuals resemble their parents. c. There must be checks on survival and reproduction in nature, or else the world would become overcrowded. d. Like compound interest, small successive changes in a trait each generation can lead to the large differences that we see between species. e. Nature acts like the breeders of pigeon, selecting the traits most useful to the organism.

c. There must be checks on survival and reproduction in nature, or else the world would become overcrowded.

Which of the following statements about garter snakes that are resistant to TTD is true? a. They are less vulnerable to their predators than are TTD-sensitive snakes. b. They do not pay a price for this resistance. c. They move more slowly than do TTD-sensitive snakes that are digesting their meals. d. They cannot eat newts. e. They lack sodium channels.

c. They move more slowly than do TTD-sensitive snakes that are digesting their meals.

The period of time in which most of the land was divided into two large land masses and in which lizards, several groups of mammals, and flowering plants first appeared was the a. Cretaceous. b. Permian. c. Triassic. d. Devonian. e. Jurassic.

c. Triassic.

According to the scientific definition of the word theory, a theory is a. a hypothesis. b. largely a matter of guesswork. c. a large body of knowledge. d. an estimate. e. a supposition.

c. a large body of knowledge.

Muller's ratchet is the a. breaking down of adaptive combinations of genes by recombination. b. elimination of deleterious mutations due to sexual reproduction. c. accumulation of deleterious mutations in asexual lineages. d. crossing over and independent assortment of chromosomes during meiosis. e. maintenance of genetic variation via disruptive selection.

c. accumulation of deleterious mutations in asexual lineages.

The Isthmus of Panama cut off gene flow between Atlantic and Pacific populations of a species of fish. The cessation of gene flow led to the accumulation of genetic differences between the populations, which led to reproductive isolation. Now Atlantic and Pacific populations of this fish are separate species that cannot interbreed, even if they were again to come into contact with each other. The process described is that of a. sympatric speciation. b. parapatric speciation. c. allopatric speciation. d. reinforcement. e. temporal isolation.

c. allopatric speciation.

The notion of potentiality in Mayr's definition of "potentially interbreeding" species applies mainly to populations of organisms that are a. sympatric. b. existing in hybrid zones. c. allopatric. d. asexual. e. experiencing an adaptive radiation.

c. allopatric.

Females of the species Drosophila pseudoobscura respond less well to courtship signals from males of their close relative D. persimilis than they do to those of males of their own species. This is an example of a. gametic isolation. b. hybrid infertility. c. behavioral isolation. d. adaptive radiation. e. sympatric speciation.

c. behavioral isolation.

Even trained biologists have difficulty telling females of iophila melanogaster and D. sechellia apart, and yet these species are reproductively isolated. Thus, these species are considered _______ species. a. lineage b. morphological c. cryptic d. Coyne's e. sympatric

c. cryptic

Tim Birkhead and his colleagues were able to boost the immune systems of male zebra finches and increase their attractiveness to females by a. enlarging their tails. b. injecting them with hormones. c. feeding them carotenoid pigments. d. increasing their caloric intake. e. injecting them with phytohemagglutinin.

c. feeding them carotenoid pigments.

Biologists recently discovered that black wolves got their coat color from exchanging genes with dogs. This is an example of

c. gene flow

Larger single-celled organisms require a higher oxygen concentration than smaller ones do because the large cells a. have a faster metabolic rate per unit mass. b. have a slower metabolic rate per unit mass. c. have a lower surface area-to-volume ratio. d. have a greater surface area-to-volume ratio. e. divide more quickly than small cells do.

c. have a lower surface area-to-volume ratio.

Abnormally high concentrations of _______ have been found in rocks dating from the end of the Cretaceous. a. lithium b. mercury c. iridium d. nickel e. tungsten

c. iridium

Before transferring sperm to the female during mating, the males of some species of beetles use their copulatory organs to remove the sperm of other males. In cases in which a female mated first with a male of a different species, the male of her own species is particularly adept at removing the other male's sperm. This is an example of _______ isolation. a. geographical b. behavioral c. mechanical d. postzygotic e. precoital

c. mechanical

The most dramatic mass extinction in Earth's history, which destroyed about 96 percent of the species, a. killed off the dinosaurs. b. occurred at the end of the Cretaceous. c. occurred at the end of the Permian. d. Both a and b e. Both a and c

c. occurred at the end of the Permian.

After the eruption of a major volcano, the concentrations of _______ are likely to increase greatly, and the temperature is likely to _______. a. oxygen; drop b. oxygen; rise c. sulfur dioxide; drop d. sulfur dioxide; rise e. carbon dioxide; rise

c. sulfur dioxide; drop

The possible collision of a large meteorite with Earth 65 million years ago may explain a. the existence of Gondwana. b. continental drift, according to Alfred Wegener. c. the mass extinction that killed off the dinosaurs. d. contemporary atmospheric conditions on Earth. e. None of the above

c. the mass extinction that killed off the dinosaurs.

The primary reason that dragonflies grew so much larger 300 million years ago than they do today is that a. they lacked predators then. b. they were able to exploit an aquatic niche that no longer exists. c. there was more oxygen in the air then. d. there was more nitrogen in the air then. e. Earth was much colder then.

c. there was more oxygen in the air then.

Hybrid zones are likely to be narrow a. in species that move around considerably during their lifetimes. b. when reinforcement is occurring. c. when there is strong selection against the hybrids. d. when the hybrids are as fit as the original species. e. when Muller's ratchet is operating.

c. when there is strong selection against the hybrids.

The current rapid climate change we are experiencing is mainly caused by the buildup of atmospheric _______.

carbon dioxide

polyploidy can arise either from...

chromosome duplication in a single species (autopolyploidy) or from the combining of the chromosomes of two different species (allopolyploidy)

In Drosophila melanogaster, body size increases as the distance from the equator increases, at least partly due to genetic differences. Population geneticists refer to such a geographical pattern as a(n) _______.

cline

Heat generated in Earth's core results in _______ currents in the magma. This process pushes the _______ plates along with the land masses on top of them.

convection; lithospheric

During the Carboniferous, _______ (sea lilies and feather stars) reached their greatest diversity.

crinoids

A group of oxygen-generating bacteria, the _______, formed rocklike structures known as stromatolites.

cyanobacteria

In a hypothetical population of tree swallows, 18 individuals are homozygous for the c4 allele, 22 individuals are heterozygous for the allele, and 10 individuals lack the allele. What is the frequency of the c4 allele? a. 0.29 b. 0.36 c. 0.40 d. 0.58 e. 0.80

d. 0.58

Approximately _______ species in the current biota have been described. a. 3,000 b. 30,000 c. 300,000 d. 1.8 million e. 10 million

d. 1.8 million

The Permian extinction occurred approximately _______ million years ago. a. 40 b. 65 c. 150 d. 250 e. 550

d. 250

The period of time between when life first evolved on Earth and the definite appearance of multicellular life was about _______ years. a. 200 million b. 500 million c. 1 billion d. 3 billion e. 5 billion

d. 3 billion

How many heterozygous individuals are expected in the new population? a. 16 b. 36 c. 40 d. 48 e. 60

d. 48

Which of the following statements about the hybrid zone in the European Bombina toads is false? a. The hybrid zone is long and narrow. b. Many of the hybrids are morphologically abnormal. c. The fitness of the hybrids is only about half that of a purebred individual. d. Adult toads are very adept at traveling long distances. e. All of the above are true; none is false.

d. Adult toads are very adept at traveling long distances.

As compared to anaerobic metabolism, aerobic metabolism is advantageous to cells because it a. proceeds at a more rapid rate. b. is more efficient. c. permits the growth of larger, more complex cells. d. All of the above e. None of the above

d. All of the above

Which of the following statements about speciation is true? a. It is usually gradual. b. It is the process by which one species splits into two daughter species. c. Reproductive isolation is an important component. d. All of the above e. None of the above

d. All of the above

Which of the following tends to reduce genetic variation within populations? a. Genetic drift b. Stabilizing selection c. Directional selection d. All of the above e. None of the above

d. All of the above

In order for a population to evolve, a. its members must have heritable genetic variation. b. natural selection must be acting on the population. c. all members of the population must have identical phenotypes. d. Both a and b e. None of the above

d. Both a and b

Which of the following factors led to the diversification of Darwin's finches? a. Environmental conditions vary among the different islands. b. Most of the islands are sufficiently distant from one another such that dispersal among populations on different islands is limited. c. Because the Galápagos Islands are only 100 km from Ecuador, they receive a continual input of new genes from the mainland. d. Both a and b e. Both a and c

d. Both a and b

Which of the following is an adaptation? a. The lion's speed, which enables the animal to capture its prey b. The process by which a lion's speed increases over many generations c. Differential survival d. Both a and b e. Both b and c

d. Both a and b

Which of the following statements about Cuatro Ciénegas is true? a. Despite being a desert, it has many aquatic species. b. It is home to species found nowhere else in the world. c. It has always remained connected to the rest of northern Mexico. d. Both a and b e. Both b and c

d. Both a and b

Which of the following statements about Levin's studies with Phlox species is true? a. The studies demonstrated the existence of reinforcement operating between these species. b. The color pattern of Phlox drummondii influences the extent to which it will mate with other species. c. P. drummondii and P. cuspidata are allopatric species. d. Both a and b e. Both a and c

d. Both a and b

Carolus Linnaeus a. originated the binomial system of nomenclature. b. differentiated species based on the biological species concept. c. classified species based on morphology. d. Both a and c e. Both b and c

d. Both a and c

Which of the following statements about adaptive radiations is true? a. They occur only on islands. b. They frequently follow mass extinctions. c. They begin when populations differentiate genetically in response to environmental differences. d. Both b and c e. All of the above

d. Both b and c

Which of the following is not considered a plausible hypothesis for the causes of mass extinctions? a. Extraterrestrial events, such as meteorite or asteroid collisions b. Glaciations c. Massive volcanic activity d. Competition among organisms e. All of the above are considered plausible hypotheses.

d. Competition among organisms

Due to various causes, including DDT poisoning, the population size of whooping cranes was reduced to about a dozen during the 1970s. The population size has since rebounded, and there are now hundreds of whooping cranes. Which of the following would you not expect to see in whooping cranes? a. Very low levels of genetic variation b. Very few heterozygous individuals c. Differences in allele frequency between current populations of cranes and historical populations d. Considerable genetic polymorphism e. All of the above would be seen in whooping cranes.

d. Considerable genetic polymorphism

The sizes of horns in males of a particular beetle have an interesting distribution: the highest frequencies are around 15 millimeters and 30 millimeters, with few individuals in between. Based on this observation, which of the following modes of selection is most likely to be operating on these horns? a. Stabilizing selection b. Directional selection c. Concentrated selection d. Disruptive selection e. Purifying selection

d. Disruptive selection

Which of the following represents the correct sequence of events, from earliest to latest? a. Permian mass extinction, decline in oxygen levels, drying of lowland swamps b. Permian mass extinction, drying of lowland swamps, decline in oxygen levels c. Decline in oxygen levels, Permian mass extinction, drying of lowland swamps d. Drying of lowland swamps, decline in oxygen levels, Permian mass extinction e. Drying of lowland swamps, Permian mass extinction, decline in oxygen levels

d. Drying of lowland swamps, decline in oxygen levels, Permian mass extinction

Which of the following represents the correct ordering of the categories, from largest to smallest? a. Epoch, period, era b. Epoch, era, period c. Era, epoch, period d. Era, period, epoch e. Period, era, epoch

d. Era, period, epoch

What was the main reason that flies became reproductively isolated from one another in Rice and Salt's experiments? a. Chromosomal changes b. Gene flow c. Genetic drift d. Evolved preferences for different habitats e. Reinforcement

d. Evolved preferences for different habitats

Which of the following places the events in correct chronological order, from earliest to latest? a. 100 million years ago, first mammals appear, dinosaurs go extinct b. 100 million years ago, dinosaurs go extinct, first mammals appear c. Dinosaurs go extinct, first mammals appear, 100 million years ago d. First mammals appear, 100 million years ago, dinosaurs go extinct e. First mammals appear, dinosaurs go extinct, 100 million years ago

d. First mammals appear, 100 million years ago, dinosaurs go extinct

Which of the following organisms would you not expect to see during a walk in a Permian forest? a. Dragonflies b. Amphibians c. Club mosses and horsetails d. Flowering plants e. Gymnosperms

d. Flowering plants

Which of the following statements about Darwin is true? a. Even as a youth he recognized that life evolves. b. He published his observations about evolution soon after the HMS Beagle arrived in England. c. He recognized that animals on the Galápagos Islands were all identical to those on the mainland. d. He had a keen interest in geology. e. All of the above

d. He had a keen interest in geology.

Which of the following statements about speciation is true? a. Wind-pollinated plants typically have higher speciation rates than animal-pollinated plants. b. Species that move have higher rates of speciation than those with limited dispersal. c. Sexual selection seems to decrease speciation rates. d. Herbivorous insects typically have higher rates of speciation compared with insects that prey on other insects. e. None of the above

d. Herbivorous insects typically have higher rates of speciation compared with insects that prey

Natural selection would never directly favor the evolution of which of the following types of reproductive isolating barriers? a. Mechanical isolation b. Gametic isolation c. Behavioral isolation d. Hybrid infertility e. None of the above

d. Hybrid infertility

What is the critical distinction between allopolyploidy and autopolyploidy? a. Allopolyploidy involves disruptive selection. b. Autopolyploidy involves disruptive selection. c. If speciation is allopatric rather than sympatric, then the mode of speciation is allopolyploidy. d. In autopolyploidy, one parental species makes up the polyploidy. e. In allopolyploidy, two parental species make up the polyploidy.

d. In autopolyploidy, one parental species makes up the polyploidy.

Which of the following statements about the Dobzhansky-Muller model of speciation is false? a. It can involve combinations of single genes. b. It can involve combinations of chromosomal rearrangements. c. It requires different mutations occurring in each of the two populations. d. It requires selection to act differently in the two populations. e. All of the above are true; none is false.

d. It requires selection to act differently in the two populations.

Which of the following statements about the mass extinction at the end of the Cretaceous is false? a. A meteorite was involved. b. Many marine invertebrates and insect species died out. c. Almost all land animals larger than about 25 kilograms, including dinosaurs, became extinct. d. It was the largest mass extinction in Earth's history. e. All of the above are true; none is false.

d. It was the largest mass extinction in Earth's history.

When researchers observe populations that have large deviations from Hardy-Weinberg equilibrium, they can safely dismiss which of the following mechanisms as the explanation for the deviation? a. Natural selection b. Gene flow c. Nonrandom mating d. Mutation e. None of the above

d. Mutation

The first person to realize that the relative ages of rocks can be determined by examining strata was a. Charles niin. b. Alfred Russel Wallace. c. Stephen Jay Gould. d. Nicolaus Steno. e. Alfred Wegener.

d. Nicolaus Steno.

Which of the following statements about mutations is false? a. Mutation rates are very low for most loci. b. Mutations are random with respect to the adaptive needs of organisms. c. Most mutations are either harmful or neutral. d. Only rarely does a human carry a new mutation in his or her genome. e. The current human population carries billions of new mutations that were not present in previous generations.

d. Only rarely does a human carry a new mutation in his or her genome.

Which of the following places the events in correct chronological order, from earliest to latest? a. First frogs, earliest fossil flowering plants, Permian extinction b. First frogs, Permian extinction, earliest fossil flowering plants c. Earliest fossil flowering plants, first frogs, Permian extinction d. Permian extinction, first frogs, earliest fossil flowering plants e. Permian extinction, earliest fossil flowering plants, first frogs

d. Permian extinction, first frogs, earliest fossil flowering plants

When hybrid offspring are at a fitness disadvantage and reinforcement does not occur, which of the following is likely to occur? a. The spreading of hybrids through both populations, resulting in the combining of both gene pools and no new species b. An adaptive radiation c. The formation of a new species via polyploidy d. The formation of a hybrid zone e. None of the above

d. The formation of a hybrid zone

For which of the following reasons would we expect rapid speciation to occur among animals with complex sexually-selected behavior patterns? a. The timing of reproduction is behaviorally mediated. b. Behavioral differences usually reflect physiological differences. c. They have difficulty in identifying members of their own species and often mate with members of other species. d. They make sophisticated discriminations among potential mates. e. They find mates more quickly and efficiently.

d. They make sophisticated discriminations among potential mates.

Vertebrates with well-protected eggs that can be laid in dry places are known as a. trilobites. b. ediacaran. c. crinoides. d. amniotes. e. dinosaurs.

d. amniotes.

The half-life of carbon-14 is 5,700 years. If 10 percent of the original carbon-14 is left in a structure, that structure is _______ years old. a. less than 2,850 b. about 5,700 c. between 11,400 and 17,100 d. between 17,100 and 22,800 e. about 57,000

d. between 17,100 and 22,800

Suppose that females of a species of beetles prefer to mate with males that have relatively rare color patterns. This observation would be an illustration of a. Muller's ratchet. b. genetic drift. c. the founder effect. d. frequency-dependent selection. e. disruptive selection.

d. frequency-dependent selection.

Natural selection works _______ on the genotype and _______ on the phenotype. a. directly; directly b. directly; indirectly c. directly; not at all d. indirectly; directly e. indirectly; not at all

d. indirectly; directly

The first flying animals were _______, which first appeared in the _______ period. a. birds; Carboniferous b. birds; Cretaceous c. bats; Jurassic d. insects; Carboniferous e. insects; Permian

d. insects; Carboniferous

The most common means of sympatric speciation occurs via a. geographic barriers. b. the hawthorn process. c. disruptive selection. d. polyploidy. e. reinforcement.

d. polyploidy.

Crosses between the flour beetles Tribolium castaneum and T. freemani result in large numbers of hybrids that survive but are sterile. This is an example of a. low hybrid zygote viability. b. behavioral isolation. c. low hybrid adult viability. d. postzygotic reproductive isolation. e. None of the above

d. postzygotic reproductive isolation.

The heat that drives plate tectonics is driven by a. radiant energy from the sun. b. chemical energy from bacteria. c. chemical energy from inorganic enzymatic cycles. d. radioactive decay inside Earth's crust. e. kinetic energy from meteorite collisions.

d. radioactive decay inside Earth's crust.

Despite inhabiting overlapping ranges, the western spotted skunk and the eastern spotted skunk do not interbreed. One reason for this lack of interbreeding is that the western species breeds in early fall and the eastern species breeds in late winter to early spring. This is an example of _______ isolation. a. chemical b. gametic c. postzygotic d. temporal e. mechanical

d. temporal

What factors influence rates of speciation?

diet, behavioral complexity, and dispersal abilities of the respective species.

Mechanical isolation

differences in the sizes and shapes of reproductive organs may prevent the union of gametes from different species

Except in cases of polyploidy, sympatric speciation usually requires the action of _______ selection.

disruptive

When _______ selection operates, individuals at opposite extremes of a character distribution contribute more offspring to the next generation than do those that are close to the mean.

disruptive

Which of the following conditions would be most conducive for the evolution of sexual reproduction and recombination? a. Large population size b. Steady temperatures c. A very efficient DNA repair system d. The elimination of pathogens e. A rapidly changing environment

e. A rapidly changing environment

The first person to put forth the idea that Earth's con-tinents are in continual but slow motion was a. Charles Darwin. b. Alfred Russel Wallace. c. Stephen Jay Gould. d. Nicolaus Steno. e. Alfred Wegener.

e. Alfred Wegener.

In Tim Birkhead's study of zebra finches, male birds fed water with added carotenoids a. had much brighter bills than control males had. b. were preferred by females. c. developed thicker skins than control males did. d. had stronger immune systems than control males had. e. All of the above

e. All of the above

Which of the following statements about a hybrid zone is false? a. It occurs where two different populations come into contact. b. It may shift in location due to environmental changes. c. Its habitat may differ from that favored by the parent populations. d. It may narrow, or even disappear, if strong isolating mechanisms develop. e. All of the above are true; none is false.

e. All of the above are true; none is false.

Which of the following statements about evolution is false? a. Scientists can observe evolution in action. b. Evolutionary theory can be applied to solve practical problems. c. Biologists have accumulated a large body of evidence about the evolutionary changes that have occurred in the past. d. Biologists have accumulated a large body of evidence about how evolutionary changes occur. e. All of the above are true; none is false.

e. All of the above are true; none is false.

Which of the following statements about population bottlenecks is false? a. They are an extreme example of genetic drift. b. They can result in changes in allele frequencies. c. They can result in the loss of genetic variation. d. They arise from severe reductions in population size. e. All of the above are true; none is false.

e. All of the above are true; none is false.

Which of the following statements about the 1918-19 influenza pandemic is false? a. Compared with most flu viruses, the virus of the pandemic hit young adults particularly hard. b. There were more deaths from this virus than there were combat deaths in World War I. c. The virus often triggered an especially intense reaction in the immune system. d. The virus was the product of evolution. e. All of the above are true; none is false.

e. All of the above are true; none is false.

Which of the following did not take place in the Devonian? a. A mass extinction marking the end of the period b. The appearance of the first gymnosperms c. An acceleration in the rates of evolutionary change in many groups of animals d. The appearance of the first known fossils of insects, spiders, and mites e. All of the above occurred in the Devonian.

e. All of the above occurred in the Devonian.

Which of the following did not occur during the Pleistocene? a. Multiple ice ages b. Humans reached North America. c. Humans reached Australia. d. The ranges of many animals and plants shifted to the equator. e. All of the above occurred.

e. All of the above occurred.

The evolution of chromosomal rearrangements in Rhogeessa bats supports the role of _______ in speciation. a. habitat isolation b. autopolyploidy c. the Dobzhansky-Muller model d. gametic isolation e. Both a and c

e. Both a and c

Which of the following statements about hybrid zones is true? a. They are excellent natural laboratories for speciation studies. b. When they first appear, most hybrid zones contain mostly recombinant individuals. c. They may result from human activity. d. Both a and b e. Both a and c

e. Both a and c

Given the diversity of dog breeds that exists, which of the following principles is likely to be true? a. The original gene pool had little genetic variation. b. Selection can yield considerable morphological change, outside the range of the original population. c. The morphological traits seen must be at least somewhat heritable. d. Both a and b e. Both b and c

e. Both b and c

The hybrids between tetraploid and diploid plants of the same ancestral species a. are usually fertile. b. are triploid. c. have chromosomes that usually segregate unevenly during meiosis. d. Both a and b e. Both b and c

e. Both b and c

Which of the following experienced major radiations during the Cenozoic? a. Non-avian dinosaurs b. Mammals c. Flowering plants d. Both a and b e. Both b and c

e. Both b and c

Which of the following statements about continental drift is true? a. When it was proposed, the idea received almost immediate acceptance. b. Continents move because as magma rises, it exerts tremendous pressure on the plates that float on top of it. c. Deep rift valleys have been generated from the same process that causes continental drift. d. Both a and b e. Both b and c

e. Both b and c

Why do most scientists and historians give Darwin more credit than Wallace regarding their contributions to evolutionary theory? a. Only Darwin provided a mechanism for evolution. b. Darwin provided more extensive evidence in support of evolution. c. Darwin developed his ideas first. d. Both a and b e. Both b and c

e. Both b and c

Which of the following modes of selection results in a decrease in variation? a. Stabilizing selection only b. Directional selection only c. Disruptive selection only d. Both directional and disruptive selection e. Both stabilizing and directional selection

e. Both stabilizing and directional selection

Which of the following geological periods is the most recent (closest to the present)? a. Devonian b. Cambrian c. Jurassic d. Silurian e. Cretaceous

e. Cretaceous

Three different alleles (b1, b2, and b3) at the b locus exist in a hypothetical population of juniper trees. If the frequency of b1 is 0.4, what can be said about the frequency of b3? a. It cannot be less than 0.4. b. It is 0.6. c. It is 0.4. d. It is 0. e. Insufficient information is given to answer the question.

e. Insufficient information is given to answer the question.

Which of the following statements about self-fertilization is false? a. It is a form of nonrandom mating. b. It can cause deviations from the Hardy-Weinberg equilibrium. c. It reduces the frequency of heterozygotes. d. It increases the frequency of homozygotes. e. It changes allele frequencies.

e. It changes allele frequencies.

The binomial system of nomenclature, by which we still classify species, was originated by a. Charles Darwin. b. Thomas Malthus. c. Carl Sagan. d. Ernst Mayr. e. None of the above

e. None of the above

What is the main reason that there are so many species of land snails in the Hawaiian Islands? a. They have complex social behaviors. b. They have excellent dispersal ability. c. They pollinate many flowers. d. All of the above e. None of the above

e. None of the above

Which of the following statements about allele frequencies is true? a. It is possible to have a negative allele frequency. b. Allele frequencies can be greater than 1 in some populations. c. The sum of all allele frequencies is 0. d. All of the above e. None of the above

e. None of the above

Which of the following statements about the Mesozoic is true? a. Atmospheric levels of oxygen fell during the Mesozoic. b. The same groups of animals that were dominant during the Permian were also dominant throughout the Mesozoic. c. Pangaea came together during the Mesozoic. d. All of the above e. None of the above

e. None of the above

Which of the following adaptations is not found among any of the species of Darwin's finches? a. Large bills for crushing large, hard seeds b. Beaks that can open cactus fruits and extract the seeds c. Long beaks for probing dead wood, crevices, and bark for insects d. Heavy bills for twisting apart wood to reach larvae inside e. None of the above; all of the adaptations are observed in these birds.

e. None of the above; all of the adaptations are observed in these birds.

Which of the following is not a condition for the Hardy-Weinberg equilibrium? a. Absence of gene flow b. Absence of differential survival among genotypes c. Random mating of individuals with respect to genotype d. Absence of genetic drift that would cause chance fluctuations of allele frequencies e. Small population size

e. Small population size

During which period did the following events occur: recovery of the biota after a major mass extinction; increase in the species richness of invertebrate groups; appearance of the first turtles and frogs; and beginnings of a large radiation of reptiles? a. Permian b. Cambrian c. Jurassic d. Cretaceous e. Triassic

e. Triassic

Which of the following is not a postzygotic isolation mechanism? a. Abnormal meiosis following fertilization b. Infertile hybrids c. Reduced viability of hybrids d. Abnormal mitosis following fertilization e. Variation in mating pheromones

e. Variation in mating pheromones

Geographical speciation is also known as a. reinforcement. b. sympatric speciation. c. Darwinian speciation. d. the biological species concept. e. allopatric speciation.

e. allopatric speciation.

Suppose one incipient species of beetle prefers to live and mate in grassy areas and its sibling incipient species prefers sandy soils. This would be an example of _______ isolation. a. temporal b. habitat c. prezygotic d. both temporal and habitat e. both habitat and prezygotic

e. both habitat and prezygotic

Mass extinctions often accompany major _______ in sea level. Such extinctions have been particularly felt among _______ animals. a. rises; terrestrial b. rises; marine c. rises; freshwater d. drops; terrestrial e. drops; marine

e. drops; marine

Malte Andersson's study of widowbirds demonstrated that a. females prefer males with unaltered tails. b. the preferences of females change according to the season. c. sexually selected traits have no benefits or costs to survivorship. d. long tails help males compete against other males. e. females prefer males with longer-than-average tails.

e. females prefer males with longer-than-average tails.

The appearance of multicellular organisms coincided with increased levels of _______ in Earth's atmosphere. a. sulfur b. hydrogen c. nitrogen d. carbon e. oxygen

e. oxygen

The classification of organisms based on their appearance is known as _______ species concept. a. the biological b. Mayr's c. the phylogenetic d. the allopatric e. the morphological

e. the morphological

The content of most standard field guides reflects _______ species concept. a. the biological b. the lineage c. Templeton's d. the ecological e. the morphological

e. the morphological

allopolyploids are often fertile because..

each of the chromosomes has a nearly identical partner with which to pair during meiosis.

The lineage species concept...

embraces the idea that sexual species are maintained by reproductive isolation, but extends the concept of a species as a lineage over evolutionary time.

More than 90 percent of the plant species on the Hawaiian Islands exist in no other region of the world; therefore, they are said to be _______ to Hawaii.

endemic

"Potentially" says that...

even though the individuals do not live in the same area, and therefore do not interbreed, other information suggests that they would do so if they were able to get together.

The reproductive contribution of a phenotype to subsequent generations (relative to the contributions of other phenotypes) is called its _______.

fitness

If there is only one allele at a locus in a particular population, that allele is said to be _______.

fixed

The entire composition of plants in a given locality is known as its _______.

flora

The preserved remains of ancient organisms, known as _______, can tell us a great deal about the morphology of extinct species.

fossils

Polydactyly (having more than five fingers on a hand) is much more common in some isolated human populations than it is elsewhere. This is most likely an example of a(n) _______, which is due to the evolutionary mechanism called _______.

founder effect. genetic drift

Females of the beetle species Tribolium castaneum can readily mate with T. freemani. If these females mate with males of both their own species and males of T. freemani, nearly all of their offspring are pure species T. castaneum with very few hybrids. This occurs because the sperm of T. castaneum blocks the sperm of T. freemani within the reproductive tract of the T. castaneum female. This is an example of _______ isolation, a form of _______ isolation.

gametic; prezygotic

Splitting of an ancestral population leads to...

genetic divergence and reproductive incompatibility in the two descendant lineages.

In small populations, the random process of _______ can cause large changes in allele frequency from one generation to the next.

genetic drift

The frequencies of different alleles at each locus and the frequencies of different genotypes in a population describe that population's _______.

genetic structure

The time in which half of a certain amount of a radioactive substance decays is known as its _______.

half-life

Speciation by Polyploidy...

has been particularly important in the evolution of plants because plants can reproduce by self-fertilization.

The original host fruit of Rhagoletis pomonella was the _______.

hawthorn

Evolutionary changes in the _______ protein on the surface of the influenza virus allow the virus to circumvent detection by our immune system.

hemagglutinin

Height in humans is largely, but not completely, due to a person's genotype. Thus, we can say that human height is a(n) _______ trait.

heritable

Individuals who carry two copies of the allele for the sickle-cell form of hemoglobin suffer from a usually fatal anemia. However, individuals who carry one sickle-cell allele have a greater resistance to malaria. Such individuals demonstrate the principle of _______, which accounts for the maintenance of both the normal and the sickle cell alleles.20. Individuals who carry two copies of the allele for the sickle-cell form of hemoglobin suffer from a usually fatal anemia. However, individuals who carry one sickle-cell allele have a greater resistance to malaria. Such individuals demonstrate the principle of _______, which accounts for the maintenance of both the normal and the sickle cell alleles.

heterozygote advantage

Warfarin is a popular and potent rodent poison, as well as a blood-thinning medicine. Rats that have one copy of the allele for resistance to warfarin have increased resistance and thus, survive better in an environment with warfarin. Rats that are homozygous for this allele are less fit than heterozygotes, even in the presence of warfarin, because they have much higher requirements for vitamin K. Which best describes what occurs in an environment with warfarin?

heterozygote advantage

Speciation rates in plants are _______ in animal-pollinated plants than in wind-pollinated plants.

higher (greater)

The fire-bellied toad and the closely related yellow-bellied toad meet in a long, narrow _______ zone that extends for almost 5,000 kilometers.

hybrid

Unless reproductive isolation is complete, closely related species may...

hybridize in areas where their ranges overlap, resulting in the formation of a hybrid zone.

The cooling of molten material can result in the formation of ________ rocks.

igneous

Speciation rates are faster...

in animal-pollinated that in wind-pollinated plants.

Suppose a hybrid zone exists between two species of salamanders that do not disperse much. If conditions change such that the salamanders disperse more, the hybrid zone will likely _______ in width.

increase

Allopolyploids may be produced when...

individuals of two different, but closely related, species interbreed.

Behavioral isolation

individuals reject or fail to recognize individuals of other species as potential mating partners

If hybrids are less fit...

individuals that breed only within their own species will leave more surviving offspring than will individuals that interbreed with another species.

In terms of their reproductive capacity, mules, which are hybrids between horses and donkeys, are a classic case of hybrid _______.

infertility (or sterility)

Evidence that meteorites hit Earth at times of mass extinctions comes from the presence of _______, a metal that is rare on Earth but common in some meteorites.

iridium

Drosophila grown in the presence of increased oxygen concentrations evolve to become _______ after only a few generations.

larger

Rapid speciation can...

lead to adaptive radiation

An evolutionary biologist makes decisions about whether to classify different salmon populations as separate species based on their phylogenies. This biologist is most likely employing the _______ species concept.

lineage

Many pairs of closely related sister species...

may exist on either side of the geographic barrier.

When differences in the shapes of reproductive organs between the males of one species and the females of the other species lead to incompatibility, the species are said to be exhibiting _______ isolation.

mechanical

Postzygotic isolating mechanisms

mechanisms that reduce the fitness of hybrid offspring

A biologist classifies two beetles as belonging to the same species because they look more similar to each other than they do to other beetles. This biologist is employing the _______ species concept.

morphological

Which of the following characteristics could not be used to determine the difference between two cryptic species of Hyla treefrogs?

morphology

The differential contribution of offspring to the next generation by various genetic types belonging to the original population is known as _______.

natural selection

significant reproductive isolation between species is therefore..

necessary for lineages to remain distinct over evolutionary time.

The long time lag between the origin of life and the appearance of multicellular life was probably at least partly due to the lack of _______ in the atmosphere for much of Earth's existence.

oxygen

The _______ dating method makes use of changes in patterns of Earth's magnetism to date rocks.

paleomagnetic

The study of the movement of major land masses, also known as _______, led to strong evidence for continental drift.

plate tectonics

The most common means of sympatric speciation is

polyploidy

Speciation rates are usually higher in groups with...

poor dispersal abilities than in groups with good dispersal abilities because even narrow barriers can be effective in dividing a species whose members are highly sedentary

Suppose there are three isolated populations of a beetle. Population A has had a constant population size of 10,000. Population B has had a constant population size of 1,000. Population C has had a constant population size of 100. We would most expect to see an increase in the frequency of deleterious alleles in population _______ due to _______.

population c. due to genetic drift

A main goal of the field of _______ is to explain the origin and maintenance of genetic variation.

population genetics

diet specialization

populations of species that have specialized diets may be more likely to diverge than those with more generalized diets

Suppose the hybrids of two salamander species exhibit reduced adult viability. These species would thus have a _______ reproductive isolating barrier.

postzygotic

One major category of reproductive isolating barriers, known as _______ reproductive isolating barriers, operate before fertilization.

prezygotic

The proliferation of a large number of daughter species from a single common ancestor is called an evolutionary _______.

radiation

Hybrid zones often contain...

recombinant individuals resulting from many generations of hybridization.

One disadvantage of sexual reproduction is that _______ breaks up adaptive combinations of genes.

recombination

Suppose that a particular species of flowering plant that lives only one year can produce red, white, or pink blossoms, depending on its genotype. Biologists studying a population of this species count 300 red-flowering, 500 white-flowering, and 800 pink-flowering plants in a population. When a census of the population is taken the following year, 600 red-flowering, 900 white-flowering, and 1,000 pink-flowering plants are observed. Which color has the highest

red

The strengthening of prezygotic barriers between two incipient species by natural selection is known as _______.

reinforcement

If reproductive isolation were always a binary function (i.e., if populations always exhibited either no reproductive isolation or complete reproductive isolation), which of the following could not exist?

reinforcement ooorrr hybrid isolation

Mayr's definition of species asserts that _______ isolation is the most important criterion for identifying species.

reproductive

Biological species concept emphasizes...

reproductive isolation is what allows sexual species to evolve independently of one another.

Once a barrier to gene flow is established...

reproductive isolation will begin to develop through genetic divergence.

Tetraploid and diploid individuals of the same species are...

reproductively isolated because their hybrid offspring are triploid.

It appears that the mechanisms of sexual selection...

result in high rates of speciation

A special type of natural selection called _______ acts on characters that determine mating success.

sexual selection

Exhibiting great morphological and ecological diversity, the 28 species of Hawaiian sunflowers, known as _______, are a prime example of an adaptive radiation.

silverswords

Sympatric solution may occur with...

some forms of disruptive selection in which individuals with certain genotypes have a preference for distinct microhabitats where mating takes place.

If reproductive isolation is incomplete when incipient species come back into contact...

some hybridization is likely to occur.

Allopatric speciation may also result when...

some members of a population cross an existing barrier and establish a new, isolated population

allopatric speciation

speciation that results when a population is divided by a physical barrier. Dominant mode of speciation in most groups of organisms.

Suppose you are the lead researcher in an influenza lab and your team has uncovered four strains that have evolved changes from last year's influenza virus. Strain A has evolved four changes in its surface proteins and three changes in its interior proteins. Strain B has evolved two changes in its surface proteins and seven changes in its interior proteins. Strain C has evolved six changes in its surface proteins and none in its interior proteins. Strain D has evolved only a single change in its surface proteins and none in its interior proteins. Assuming that all other factors are equal, which of these strains is most likely to be infectious?

strain b

The layers of rocks, also known as _______, are often found in a chronological sequence, with the oldest rocks at the _______.

strata; bottom

Species of lacewings apparently evolved reproductive isolation without geographical isolation. This is an example of _______ speciation.

sympatric

Suppose two species of morning glories are reproductively isolated because their flowers bloom at different times. This would be an example of _______ isolation, a form of _______ isolation.

temporal; prezygotic

Define dispersal ability

the distance a species can move from an existing population or the parent organism

define polyploidy

the duplication of sets of chromosomes within individuals

"Actually" says that...

the individuals live in the same area and interbreed with one another.

Speciation requires...

the interruption of gene flow within a species whose members formerly exchanged genes.

reproductive isolation is responsible for...

the morphological distinctiveness of most species, because mutations that result in morphological changes cannot spread between reproductively isolated species.

The morphological species concept emphasizes...

the practical aspects of recognizing species, although it sometimes results in underestimation or overestimation of the actual number of species.

If polyploidy arises in several offspring of a single parent...

the siblings can fertilize one another.

If reinforcement is occurring...

then sympatric populations of closely related species are expected to evolve more effective prezygotic reproductive barriers than do allopatric populations of the same species.

The word _______ refers to the total body of work on the understanding and applications of a field of knowledge.

theory

As pairs of species diverge genetically,

they become increasingly reproductively isolated

In several species of insects, males with large testes often have better mating success but take longer to develop than those with small testes. Such a pattern is an example of a(n) _______.

trade-off

According to the Dobzhansky-Muller model, the evolution of reproductive isolation requires changes at (at least) _______ genetic loci.

two

An autopolyploidy individual orignates when...

two accidentally unreduced diploid gametes combine to form a tetraploid individuals

Cryptic species

two or more species that are morphologically indistinguishable but do not interbreed

Habitat Isolation

when two closely related species evolve preferences for living or mating in different habitats, they may have never come into contact during their respective mating periods.