Biol.111 Evolution Exam

Thomas Hunt Morgan

American drosophilist that discovered sex chromosomes, was inspired by the Galapagos mockingbirds

Speciation without geographic isolation is called _____________ speciation. A) sympatric B) allopatric C) incomplete D) diversifying E) punctuated

A) sympatric

Mechanical isolation may occur when two species have different: A) sized and shaped copulatory organs B) courtship displays C) times of the day that they are sexually active D) habitat ranges E) chemical compatibilitie of their gametes

A) sized and shaped copulatory organs

The recessive allele of a gene causes cystic fibrosis. For this gene among Caucasians, p = 0.98. If a Caucasian population is in Hardy-Weinberg equilibrium with respect to this gene, what proportion of babies is born homozygous recessive, and therefore suffers cystic fibrosis? A) 0.02^2 = 0.0004 B) 0.02 C) 0.982 = 0.9604 D) 2(0.02 × 0.98) = 0.0392 E) 0.98

A) 0.02^2 = 0.0004

A population is A) a group of individuals of the same species living in the same place at the same time. B) all individuals of a species, regardless of location or time period in which they live. C) a group of individuals of different species living in the same place and time. D) a group of individuals of a species and the other species with which they interact. E) a group of species that share a common characteristic.

A) a group of individuals of the same species living in the same place at the same time.

The emergence of many diverse species from a common ancestor that finds itself in a new environment is called A) adaptive radiation. B) gradualism. C) disruptive selection. D) allopatric speciation. E) hybridization.

A) adaptive radiation.

During Hurricane Marilyn, 15 green iguanas were blown out to sea from the island of Guadalupe. They floated on mats of vegetation for several weeks until they landed on the island of Anguilla. If these green iguanas evolve reproductive barriers and become a new species, this would be an example of: A) allopatric speciation B) sympatric speciation C) postzygotic barrier D) a miracle E) none of the above

A) allopatric speciation

Which form of speciation is thought to be most common? A) allopatric speciation B) ecological speciation C) sympatric speciation D) haploploid speciation E) none of the above

A) allopatric speciation

Which of the following best expresses the concept of natural selection? A) differential reproductive success based on inherited traits B) inheritance of acquired characteristics C) change in response to need D) a process of constant improvement, leading eventually to perfection E) survival of the fastest

A) differential reproductive success based on inherited traits

Many cichlids can be similar in appearance. If species are identified by using information about diet and the water depth at which the fish swims, the _____________ species concept is being applied. A) ecological species concept B) phylogenetic species concept C) morphological species concept D) biological species concept E) behavioral species concept

A) ecological species concept

Genetic differences between populations tend to be reduced by A) gene flow. B) mutation. C) the founder effect. D) the bottleneck effect. E) natural selection.

A) gene flow.

Speciation, or the formation of new species . . . A) is the splitting of a parent species into two or more new species B) requires geographic isolation C) requires a long time to occur D) is an event that has occurred only a few times in the history of the planet E) none of the above

A) is the splitting of a parent species into two or more new species

The original source of all genetic variation is _____. A) mutation B) meiosis C) a need for new traits D) natural selection E) recombination

A) mutation

Genetic drift results in a change in gene frequencies because A) the population size is so small that chance occurrences can alter gene frequencies. B) reproduction is non-random within the population. C) gene flow within the population is less than gene flow between populations. D) the population has not yet stabilized. E) the population is so large that natural selection has little noticeable effect

A) the population size is so small that chance occurrences can alter gene frequencies.

Suppose that, with regard to a particular genetic locus with two alleles, A and a, we know that 60% of the alleles in the gene pool of a particular large population are A. Suppose further that we observe this population for five generations, during which we know that no mutation, selection, or migration has occurred. After this period, the frequency of the a allele is expected to be _____. A) 0.6 B) 0.4 C) 0.25 D) 0.16 E) 0.5

B) 0.4

The sickle-cell allele produces a serious blood disease in homozygotes. Why doesn't natural selection eliminate this allele from all human populations? A) Natural selection is a positive force, so it does not eliminate alleles. B) In populations where endemic malaria is present, heterozygotes have an important advantage: They are resistant to malaria and therefore are more likely to survive and produce offspring that carry the allele. C) Genetic drift tends to keep the allele present in human populations. D) Mutations keep bringing the allele back into circulation. E) Natural selection occurs very slowly, but elimination of the sickle-cell allele is expected to occur soon.

B) In populations where endemic malaria is present, heterozygotes have an important advantage: They are resistant to malaria and therefore are more likely to survive and produce offspring that carry the allele.

A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a trait determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only ten remain, and those birds all have yellow feathers. Which of the following statements is true? A) Assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds. B) The hurricane has caused a population bottleneck and a loss of genetic diversity. C) This situation illustrates the principle of adaptive radiation. D) This situation illustrates the effect of a mutation event. E) The ten remaining birds will mate only with each other, and this will contribute to gene flow in the population.

B) The hurricane has caused a population bottleneck and a loss of genetic diversity.

Tay-Sachs is inherited as an autosomal recessive allele. Homozygous individuals die within the first few years of life. However, there is some evidence that heterozygous individuals are more resistant to tuberculosis. Which of the following statements about Tay-Sachs is true? A) The allele for Tay-Sachs is selected for. B) This is an example where selection for the heterozygous individuals outweighs selection against the homozygous individuals, and the allele stays in the population. C) Tay-Sachs disease will disappear soon.. D) Genetic drift will be more important to the heterozygotes than the homozygotes. E) Heterozygotes will be more fit than either homozygote regardless of environmental conditions.

B) This is an example where selection for the heterozygous individuals outweighs selection against the homozygous individuals, and the allele stays in the population.

Which mechanism for evolution was proposed by Lamarck? A) evolution by spontaneous generation B) evolution by inheritance of acquired traits C) evolution by natural selection D) evolution of the asexual reproduction E) evolution of the modern motorcycle.

B) evolution by inheritance of acquired traits

Animals that possess homologous structures probably _____. A) are headed for extinction B) have a common ancestor C) have increased genetic diversity D) by chance had similar mutations in the past E) are not related

B) have a common ancestor

Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of A) biogeographic similarity. B) homology. C) independently acquired traits. D) adaptation by natural selection. E) coincidental similarity.

B) homology.

Frequency-dependent selection, as seen in the case of the scale-eating fish in Lake Tanganyika, tends to A) eliminate rare alleles and favor whichever allele is initially most frequent. B) maintain two phenotypes in a dynamic equilibrium in a population. C) produce random changes in allele frequencies. D) lead to heterozygote advantage. E) stimulate new mutations

B) maintain two phenotypes in a dynamic equilibrium in a population.

Imagine that you are studying a very large population of moths that is isolated from gene flow. A single gene controls wing color. Half of the moths have white-spotted wings (genotype WW or Ww) and half of the moths have plain brown wings (ww). There are no new mutations, individuals mate randomly, and there is no natural selection on wing color. How will p, the frequency of the dominant allele, change over time? A) p will increase; the dominant allele will eventually take over and become most common in the population. B) p will neither increase nor decrease; it will remain more or less constant under the conditions described. C) p will decrease because of genetic drift. D) p will increase initially, then decrease until the W allele vanishes from the population. E) p will fluctuate rapidly and randomly because of genetic drift.

B) p will neither increase nor decrease; it will remain more or less constant under the conditions described.

In the Hardy-Weinberg equation, the frequency of homozygous dominant individuals in a population is equal to A) q or p. B) p2. C) 2pq. D) q2. E) 2p.

B) p2.

In natural selection, __________ determines which phenotypes are successful A) chance B) the environment C) sample size D) genetic drift E) human intervention

B) the environment

Which of the following represents a pair of homologous structures? A) the wing of a bat and the scales of a fish B) the wing of a bat and the flipper of a dolphin C) the antennae of an insect and the eyes of a bird D) the feathers of a bird and the wing membrane of a bat E) the wing of a bat and the wing of a butterfly

B) the wing of a bat and the flipper of a dolphin

Chihuahuas, Border Collies, and Great Danes (all domestic dogs) descend from the same wolf species and can still interbreed. These varieties were produced by A) speciation. B) artificial selection. C) natural selection. D) genetic drift. E) inheritance of acquired traits.

B)Artificial selection

Which of the following terms represents the frequency of heterozygotes in a population that is in Hardy-Weinberg equilibrium? A) p B) q C) 2pq D) q2 E) p2

C) 2pq

Which of the following would tend to promote adaptive radiation? A) An area has a high number of species that exploit most of the available ecological opportunities. B) An organism has a very stable set of features and capabilities over long spans of evolutionary time. C) An species colonizes an isolated area that has many empty habitats. D) An organism colonizes an area that already has a high level of existing species diversity. E) A single species goes extinct, but it has several competitors that quickly expand to assume its ecological roles.

C) An species colonizes an isolated area that has many empty habitats.

Which of the following statements regarding natural selection is false? A) Natural selection is more of an editing process than a creative mechanism. B) Natural selection depends on the local environment at the current time. C) Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness. D) Natural selection and evolutionary change can occur in a short period of time (a few generations). E) Natural selection can be observed working in organisms alive today.

C) Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness

Scientists have warned doctors of the danger of their increasing use of antibiotics (for instance, penicillin) for treating minor illnesses. They are concerned because ____________. A) humans will become tolerant to the effects of drugs B) excessive use of these drugs leads to a diminished sensitivity to them C) strains of microorganisms that are resistant to these drugs will be selected D) the drugs will be metabolized more quickly by our bodies, decreasing their effectiveness E) none of these

C) strains of microorganisms that are resistant to these drugs will be selected

The Monterey pine and the Bishop's pine inhabit some of the same areas of central California. The Monterey pine releases pollen in February, while the Bishop's pine does so in April. This is an example of __________________ isolation. A) behavioral B) postzygotic C) temporal D) habitat E) mechanical

C) temporal

The evolutionary effects of genetic drift are greatest when _____. A) the population size is large B) intraspecific competition is intense C) the population size is small D) intraspecific competition is weak E) sexual selection occurs

C) the population size is small

Each of us is part of the ongoing evolution of the human species. Which of the following would have the greatest impact on the future biological evolution of the human population? A) You work out every day so that you stay physically fit and healthy. B) A mutation occurs in one of your skin cells. C) You move to Hawaii, the state with the longest life expectancy. D) A mutation occurs in one of your sperm or egg cells. E) You encourage your children to develop their intellectual abilities.

D) A mutation occurs in one of your sperm or egg cells.

Which of the following statements would Darwin have disagreed with? A) Species change over time. B) Living species have arisen from earlier life forms. C) Modern species arose through a process known as "descent with modification." D) Descent with modification occurs through inheritance of acquired characteristics. E) Descent with modification occurs by natural selection

D) Descent with modification occurs through inheritance of acquired characteristics.

If you had to choose, where would you rather get infected with a serious bacterial disease? A) In a hospital, where most of the bacteria are probably already weakened by antibiotics in the environment. B) In a livestock barn where the animals have been treated with antibiotics. C) In a big city where antibiotics are routinely prescribed by doctors. D) In a remote, sparsely populated area where the bacteria have not been exposed to antibiotic drugs. E) It doesn't make any difference a serious bacterial illness is going to have a similar impact on your health regardless of where you pick it up.

D) In a remote, sparsely populated area where the bacteria have not been exposed to antibiotic drugs.

Which of the following is the best example of gene flow? A) A plant develops more chromosomes. B) Genes are shuffled by the crossing over of chromosomes during meiosis. C) An earthquake results in the formation of a canyon, splitting a population of toads apart. D) Wind blows pollen from one population of plants to another and cross- fertilization occurs. E) All the mutations in a population were neutral.

D) Wind blows pollen from one population of plants to another and cross- fertilization occurs.

The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes __________________ speciation. A) punctuated B) phylogenetic C) sympatric D) allopatric E) biogeographic

D) allopatric

According to Linneaus' naming scheme, which describes the largest number of organisms? A) family B) order C) genus D) class E) species

D) class

Homologous structures, such as a bat wing and dolphin flipper, A) are structures that did not develop in response to natural selection. B) are formed from genes on the same pair of chromosomes. C) are the result of pairs of chromosomes that are identical in bats and whales. D) have the same underlying structure due to inheritance from a common ancestor. E) are similar externally but have different basic structures and were probably not derived from a common ancestor.

D) have the same underlying structure due to inheritance from a common ancestor.

Which of the following can cause evolutionary change? A) migration of individuals from a population that has a different allele frequency. B) non-random reproduction. C) genetic drift in a small population. D) Two of these are correct. E) A, B, and C are all correct.

E) A, B, and C are all correct.

The morphological species concept: A) is not applicable to all forms of life, past and present B) defines species by observable and measurable physical traits C) is based on the idea of reproductive isolation D) requires that an organisms DNA be analyzed E) all of the above

E) all of the above

The biological species concept defines a species as a group of organisms that: A) are physically similar B) are genetically similar C) share a recent common ancestor D) live together in a location and carry out identical ecological roles E) are from a group or population that can interbreed.

E) are from a group or population that can interbreed

Red sea urchins and purple sea urchins occur in the same area and release their gametes at the same time into the ocean. The sperm and eggs often bump into each other but do not create hybrids because of incompatible proteins on their surfaces. This is an example of: A) temporal isolation B) habitat isolation C) behavioral isolation D) mechanical isolation E) gametic isolation

E) gametic isolation

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

E) the bear that leaves the most descendants

Jean Baptiste Lamark

Recognized as the first person to formalize a mechanism of evolutionary change, though triats acquired during an organisms lifetime were passed on to the offspring

Carolus Linnaeus

Scandinavian plants: named Genus and species= Latin names, father of Modern Taxonomy

Charler Darwin

first described the theory of Natural Selection in his book " The Origin of Species", Circumnavigated the globe on the HMS Beagle as a gentlemen's companion and naturalist