BYU Independent Study Biology 100 Exam 3 Lesson 14
The different species of Galapagos finches developed from a single mainland ancestral finch through:
adaptive radiation
The form of speciation dependent upon a geographic barrier is:
allopatric
The type of speciation in which subpopulations become geographically isolated is called:
allopatric speciation
When individuals tend to mate with those that have the same phenotype with respect to some characteristic, __ occurs.
assortative mating
When the ratio of two or more phenotypes remains the same in each generation it is called:
balanced polymorphism
The rejection of finch suitors with the wrong type of beak is a __ type of isolating mechanism.
behavioral
The use of pheromones is a form of __ isolation.
behavioral
Populations that originate from a small number of individuals have a reduced number of alleles. This is called the:
founder effect
The ability of a plant's stigma to control which pollen grains can successfully complete pollination is a type of __ isolating mechanism.
gamete
If two individuals in neighboring populations mate but their gametes cannot fuse to form a zygote, this is an example of: __.
gamete isolation
If there is an absence of migration of breeding individuals among populations __ will not occur.
gene flow
All of the alleles of all individuals in the population is called a:
gene pool
The various alleles at all the gene loci in all individuals make up the __ of the population.
gene pool
Cheetahs are a good illumination of how __ can cause certain alleles to be lost from a population.
genetic drift
In the Hardy-Weinberg equation, 2pq = the percentage of __?
heterozygotes
In areas of Africa where malaria is prevalent, individuals who are __ for sickle cell disease are fitter than others with other genotypes.
heterozygous
The __ individuals in a population will remain a source of the recessive allele since it is not phenotypically different.
heterozygous
Characteristics of animal genitalia or plant floral structures which make mating with other species impossible are forms of __ isolation.
mechanical
The study of how evolution works at the genetic level is called:
microevolution
Evolution that occurs within a population is called:
microevolution.
In sympatric speciation individuals in the population become reproductively isolated because of:
mutations, not geographical factors.
The final result of changes in the gene pool allele and genotypic frequencies is:
speciation
When the majority of types of genotypes are prevented from participating in the production of the next generation, ___ has occurred.
the bottleneck effect
Populations that experience a near extinction event have fewer individuals and fewer alleles to contribute to the next generation. This is known as:
the bottleneck effect.
Hardy and Weinberg used the binomial expression:__ to calculate the __ frequencies and __ frequencies of a population.
(p2 + 2pq + q2) genotypic frequencies and allelic frequencies.
What is the frequency of the recessive allele in a population of 100 individuals with the following genotype: 30BB, 60Bb, 10bb?
0.4
If the frequency of the recessive allele is 0.45 what is the frequency of the dominant allele?
0.55
What is the frequency of the dominant allele in a population of 100 individuals with the following genotype: 30BB, 60Bb, 10bb?
0.6
What is the number of dominant alleles in a population of 100 individuals with the following genotype: 30BB, 60Bb, 10bb?
120
Assuming a Hardy-Weinberg equilibrium, 21% of a population is homozygous dominant, 50% is heterozygous, and 29% is homozygous recessive. What percentage of the next generation is predicted to be homozygous recessive?
29%
Populations that lack variation may __: (Choose all that apply) a. become extinct b. not be able to adapt to new conditions.
A and B
Speciation is: (Choose all that apply) a. the splitting of one species into two or more new species b. the transformation of one species into a new species over time
A and B
Which of these is a prezygotic isolating mechanism: (choose all that apply) a. habitat isolation b. temporal isolation c. hybrid sterility d. zygote mortality
A and B
Which of the following statements best matches the evolutionary species concept? a. Some phenotypically distinct "species" may interbreed and leave fertile progeny b. Groups of organisms may be in different stages of speciation, and may share a portion of their gene pools. c. The members of one species interbreed and have a common gene pool. d. Different species are reproductively isolated from one another, ie they do not interbreed or leave fertile progeny.
A and B C and D are the biological concept of species.
Small populations develop as a result of the __ which leads to genetic __ that affects gene pool frequencies. (Choose all that apply) a. founder effect b. bottleneck effect
A and B drift
Random mating occurs when: (Choose all that apply) a. individuals pair by choice b .individuals pair according to genotypes c. individuals pair according to phenotypes
A only
The occurrence of disruptive selection in British Land Snails created: (Choose all that apply) a. two different phenotypes, snails with dark shells and snails with light-colored shells b. one intermediate phenotype, snails with mottled shells c. a large number of snails with dark shells
A only
Which of the following is/are an example(s) of sexual selection: a. the attraction of peahens to a male peacock with an elaborate tail b. tall humans mating with other tall humans c. inbreeding
A only
Which of the following is/are postzygotic isolating mechanisms: (Choose all that apply) a. hybrid sterility b. habitat isolation c. mechanical isolation d. temporal isolation
A only
A mutation in a rabbit population that affects their leg muscles such that some of them are not able to run as fast to escape predators would: (Choose all that apply) a. indicate the population is under selection pressure b. mean the population is not at Hardy-Weinberg equilibrium c. result in a change in allele frequencies in the population d. mean microevolution is taking place
A, B, C, and D
Which of the following is a postzygotic isolating mechanism: (Choose all that apply) a. reduced F2 fitness b. zygote mortality c. hybrid sterility d. embryo or fetus mortality
A, B, C, and D
Which of these cannot occur if a population is to maintain an equilibrium of allele frequencies? (choose all that apply) a. People leave one country and relocate in another b. A disease wipes out the majority of a herd of deer. c. Members of an Indian trive only allow the two tallest people in a tribe to marry each spring. d. Large black rats are the preferred males in a population of rats.
A, B, C, and D
Which of these is/are necessary to natural selection: (choose all that apply) a. variations b. differential reproduction c. inheritance of differences d. differential adaptiveness
A, B, C, and D
A mutation can be: (Choose all that apply) to an organism a. beneficial b. neutral in its effect c. harmful
A, B, and C
Evolution by natural selection requires: (Choose all that apply) a. differential reproduction b. inheritable genetic differences c. differential adaptedness
A, B, and C
Inbreeding (Choose all that apply) a. does not change allele frequencies b. decreases the proportion of heterozygotes at all gene loci c. increases the frequency of recessive abnormalities in the phenotype in humans.
A, B, and C
The finch populations on the various Galapagos islands experienced __ resulting in the formation of different species of finches. (Choose all that apply) a. the founder effect b. natural selection c. adaptive radiation
A, B, and C
The research that studied the effect of industrial melanism on moth populations demonstrates that: (Choose all that apply) a. microevolution does occur b. phenotypes in a population can change c. selection pressure can change allele frequencies
A, B, and C
The shift in the population of peppered moths from 10% dark-colored moths prior to the advent of industry to 80% dark-colored moths after the advent of industry illustrates the process of: (Choose all that apply) a. microevolution b. macroevolution c. industrial melanism
A, B, and C
Variation is measured by: (Choose all that apply) a. mutation b. gene flow c. diploidy
A, B, and C
Which of the following correctly describe(s) a species: (Choose all that apply) a. members of a species can interbreed b. members of a species have a shared gene pool c. members or a species are unable to successfully breed with members of other species.
A, B, and C
Which of the following might be a cause of genetic drift: (Choose all that apply) a. overharveting b. habitat loss c. earthquake
A, B, and C
What is the correct matching pattern between the following terms and the descriptions: a. stabilizing selection I. Organisms with an extreme genotype are favored over those with a less extreme genotype b. disruptive selection II. Organisms with an intermediate genotype are favored over those with either of the extreme genotypes c. directional selection III. Two or more genotypes are favored over organisms with intermediate genotypes
A-II Stabilizing=intermediate genotypes B-III Disruptive = two or more genotypes C- I Directional = extreme genotypes
What is the correct matching pattern between the terms on the left and the descriptions on the right: A. p I. Frequency of the heterozygous genotype B. q II. Frequency of the dominant allele C. p2 III. Frequency of the recessive allele D. q2 IV. Frequency of the homozygous dominant genotype E. 2pq V. Frequency of the homozygous recessive genotype
A-II p=dominant allele B-III q=recessive allele C-IV p(squared)=homozygous dominant genotype D-V q(squared)=homozygous recessive genotype E-I 2pq=frequency of the heterozygous genotype
In a population that has the following numbers of individuals in each of the following genotypes (AA=72, Aa=89, aa=29) what is the allele frequency for each allele?
A=0.61 a=0.39
In a population that has the following numbers of individuals in each of the following genotypes (AA=72, Aa=89, aa=29) and assuming that individuals carrying the homozygous recessive genotype are sterile, how many individuals of each genotype will there be in a population of 250 individuals?
AA = 130 Aa = 100 aa = 20
In a population that has the following numbers of individuals in each of the following genotypes (AA=72, Aa=89, aa=29) and assuming that the allele frequency does not change, how many individuals of each genotype will there be in a population of 250 individuals?
AA=93 Aa=120 aa=37
A recessive allele that causes polydactylism is found in an unusually large percentage of the __ of __ County, PA because of __.
Amish, Lancaster, the founder effect
A population of small river fish lay their eggs among the reeds along the banks of the river. Some have a genotype that causes them to lay their eggs at the base of the reeds where predators are less likely to find them. Others have a genotype that causes the outer layer of the eggs to have a coloration that camouflages them from the view of predators. After many generations the two kinds of fish aren't able to interbreed. This is an example of: (Choose all that apply) a. stabilizing selection b. disruptive selection c. a prezygotic isolating mechanism d. speciation
B and D
Polyploid plants can successfully reproduce: (Choose all that apply) a. only with diploid plants b. only with other like polyploid plants c. with any plants
B only
The homozygote Hb^s Hb^s persists because: (choose all that apply) a. it offers protection against malaria b. the heterozygote offers protection against malaria c. the genotype Hb^a Hb^a offers protection against malaria d. sickle cell disease is worse than sickle cell trait
B only
The industrial melanism of the peppered moth is an example of __ selection: (Choose all that apply) a. stabilizing b. directional c. sexual d. disruptive
B only
When organisms adapt to the abiotic environment they become adapted to __: (Choose all that apply) a. predation b. extreme temperature c. parasitism
B only
Which of the following is not an example of directional selection: (Choose all that apply) a. the gradual increase in size of the modern horse b. survival of average weight infants c. the increasing resistance of the malaria causing protozoan to chloroquinine d. the increasing number of dark-colored peppered moths after the advent of industry
B only
The many species of Galapagos finches are each adapted to eating different foods. This is the result of: (choose all that apply) a. gene flow b. adaptive radiation c. sympatric speciation d. genetic drift
B only, adaptive radiation
When a population is small, there is a greater chance of: a. gene flow b. genetic drift c. natural selection d. mutations occurring e. sexual selection
B, genetic drift
Allopatric but not sympatric speciation requires: a. reproductive isolation b. geographic isolation c. prior hybridization d. spontaneous differences in males and females e. changes in gene pool frequencies
B, geographic isolation
A population of goldenrod plants that is growing on a sand dune contains some individuals that have a genotype that gives them a greater tolerance for dry soil than do other plants. Sand continues to blow onto the dune, increasing its height, and increasing the distance between the plant roots and available water. Eventually, a greater number of drought-tolerant goldenrods are found in the population. This is an example of: (Choose all that apply) a. a post-zygotic isolating mechanism b. stabilizing selection c. directional selection d. disruptive selection
C only
Gene flow: (Choose all that apply) a. is the result of change in the nucleotide sequence of DNA b. among populations increases the rate of speciation c. tends to decrease the genetic diversity among populations
C only
Genetic drift: (Choose all that apply) a. is more likely to occur in large populations b. increases genetic variability in a population c. may begin when a species becomes nearly extinct
C only
Misuse of antibiotics: (Choose all that apply) a. cause bacteria to become resistant to antibiotics b. cause people to become immune to antibiotics c. select for bacteria that are already resistant to antibiotics
C only
Sympatric speciation can occur due to: (Choose all that apply) a. geographic isolation b. random mating c. hybridization
C only
Which of the following conditions will cause evolution within a population to occur? (Choose all that apply) a. no mutations b. random mating c. natural selection
C only
Which of these is/are an example of stabilizing selection? (choose all that apply) a. Over time, Equus developed strength, intelligence, speed, and durable grinding teeth. b. British land snails mainly have two different phenotypes. c. Swiss starlings usually lay four or five eggs, thereby increasing their chances of more offspring. d. Drug resistance increases with each generation; the resistant bacteria survive, and the nonresistant bacteria get killed off.
C only
Which one of the following is not one of the assumptions of the Hardy-Weinberg principle: (Choose all that apply) a. no mutation b. no selection c. non-random mating d. no genetic drift e. no immigration or emigration
C only
Male moths recognize females of their species by sensing chemical signals called pheromones. This is an example of: a. gamete isolation b. habitat isolation c. behavioral isolation d. mechanical isolation e. temporal isolation
C, behavioral isolation
The offspring of better-adapted individuals are expected to make up a larger proportion of the next generation. The most likely explanation is: a. mutations and nonrandom mating b. gene flow and genetic drift c. mutations and natural selection d. mutations and genetic drift
C, mutations and natural selection
A human population has a higher-than usual percentage of individuals with a genetic disorder. The most likely explanation is: a. mutations and gene flow b. mutations and natural selection c. nonrandom mating and genetic drift d. nonrandom mating and gene flow
C, nonrandom mating and genetic drift.
The continued occurrence of sickle-cell disease with malaria in parts of Africa is due to: a. continual mutation b. gene flow between populations c. relative fitness of the heterozygote d. disruptive selection e. protozoan resistance to DDT
C, relative fitness of the heterozygote
An individual's fitness affects: (Choose all that apply) a. variation b. inheritance c. differential adaptedness d. differential reproduction
D only
The biological definition of a species is simply the: a. anatomical and developmental differences between two groups of organisms. b. geographic distribution of two groups of organisms. c. differences in the adaptations of two groups of organisms. d. reproductive isolation of a group of organisms. e. difference in mutations between two groups of organisms.
D: reproductive isolation of a group of organisms
When an extreme phenotype is favored and the distribution curve shifts in that direction, __ selection occurs.
Directional
When two or more extremes of phenotypes are favored over any intermediate phenotype __ selection occurs.
Disruptive selection
Which of the following is not a prezygotic isolating mechanism: (Choose all that apply) a. habitat isolation b. temporal isolation c. behavioral isolation d. reproductive behavior e. hybrid sterility
E only
Which of these is mechanical isolation: (choose all that apply) a. sperm cannot reach or fertilize an egg b. courtship pattern differs c. living in different locales d. reproducing at different times of the year e. genitalia are unsuitable to each other
E only
A population of red maples will interbreed with a population of sugar maples. (T/F)
False
Fitness does not vary according to the environment in which an individual lives. (T/F)
False
Hybrids are typically fertile and the offspring of hybrids are always fertile. (T/F)
False
In his book, Origin of Species, Darwin clearly stated how variations came about and how they were transmitted. (T/F)
False
Studies on many species have demonstrated that high levels of allelic variation are the exception rather than the rule in natural populations. (T/F)
False
The dominant allele is the most common allele in the gene pool. (T/F)
False
When the different species of Galapagos finches happen to reside on the same island they interbreed. (T/F)
False
Disruptive selection occurs when an intermediate phenotype is favored. (T/F)
False.
The Hardy-Weinberg law states that an equilibrium of allele frequencies in a gene pool will remain in effect in each succeeding generation of of a sexually reproducing population as long as __(number) conditions are met.
Five
Of the conditions that can cause a deviation from the Hardy-Weinberg equilibrium, only __ causes adaptation to the environment.
Natural Selection
All the members of a single species occupying a particular area at the same time is a __.
Population
Which type of selection improves adaptation of the population to those aspects of the environment that remain constant?
Stabilizing selection
A mating season specific to each species is a form of prezygotic isolation. (T/F)
True
Assortative mating results in increased homozygotes for the gene loci that control a certain trait and decreased heterozygotes for the same loci. (T/F)
True
Evolution can be detected by noting any deviation from a Hardy-Weinberg equilibrium of allele frequencies in the gene pool of a population. (T/F)
True
Gene flow can increase the variation within a population by introducing novel alleles from some other species. (T/F)
True
Gene flow occurs between the populations of a species, but not between populations of different species. (T/F)
True
Gene mutations are the ultimate source of variation. (T/F)
True
Genetic drift is a random process. (T/F)
True
Genetic drift is more likely to occur in a small population. (T/F)
True
If there is migration of individuals into or out of a population, evolution will occur. (T/F)
True
Most of the traits on which natural selection acts are polygenic. (T/F)
True
Natural selection is the process that results in adaptation of a population to the biotic and abiotic environments. (T/F)
True
Only alleles that cause a phenotypic difference are subject to natural selection. (T/F)
True
Prezygotic isolating mechanisms are those that prevent reproduction attempts and make it unlikely that fertilization will be successful if mating is attempted. (T/F)
True
Sexual reproduction alone cannot bring about a change in allele frequency. (T/F)
True
The inaccessibility of pollen to certain pollinators can prevent cross-fertilization. (T/F)
True
The increased fitness of the individuals who are hetereozygous for sickle-cell disease in areas where malaria is prevalent maintain the recessive allele in the population.
True
Traits that are controlled by more than one pair of alleles located at different gene loci display a range of phenotypes, the frequency distribution of which usually resembles a bell-shaped curve. (T/F)
True
When a population is geographically isolated from other populations gene flow stops. (T/F)
True
