Biology 1620 (EXAM 3)
What are the 3 conditions of natural selection?
1) Phenotypic (observable, measurable) variation 2) Fitness differences associated with variation. Variation matters for survival or reproduction 3) Some of the variation has a genetic basis,that is, some genotypes leave more offspring(and more gene copies) than others
What are the 5 conditions for Hardy-Weinberg Equilibrium?
1. No mutations: 2. Random mating: 3. No natural selection: 4. Extremely large population size: 5. No gene flow:
In the beetles described in the animation, there were two alleles for color, brown and green. Suppose that you discover a very small population of these beetles, consisting of the individuals shown below. How can you calculate the frequency of each allele in this population?
1. To calculate the frequency of the brown allele, count the number of brown alleles and divide by the total number of alleles in this population. 2. In this beetle population, the number of brown alleles is 8. 3. In this beetle population, the total number of alleles is 20. 4. The frequency of the brown allele in this beetle population is 0.4. 5. The frequency of the green allele in this beetle population is 0.6. *Allele frequencies measure the relative proportions of different alleles in a population. By looking at how allele frequencies change over time, you can see how populations are evolving.
"Gee, expecting evolution by natural selection to produce something as complex as the vertebrate eye is like expecting a tornado to blow through a junkyard and assemble a Boeing 747!" This naive statement is incorrect because: A. unlike the wind, natural selection causes phenotypic change in a non-random direction B. unlike the wind, natural selection is a conscious process C. unlike the wind, natural selection can anticipate an organism's future needs D. unlike the wind, natural selection produces rapid change E. most Boeing 747s really ARE produced by strong winds blowing through junkyards!
A
Arrange the following from most inclusive to least inclusive: 1. Natural selection 2. Microevolution 3. Intrasexual selection 4. Evolution 5. Sexual selection A. 4, 2, 1, 5, 3 B. 4, 1, 3, 2, 5 C. 4, 2, 1, 3, 5 D. 1, 4, 2, 5, 3 E. 1, 2, 4, 5, 3
A
Birds in which female plumage is brighter than male plumage are likely to be: A. polyandrous B. polygynous C. monogamous D. asexual E. shunned by other birds and not allowed to join in any reindeer games
A
Directional selection on body size in fruit flies will occur when: A. smaller-than-average phenotypes have the highest fitness B. intermediate phenotypes have the highest fitness C. intermediate phenotypes have the lowest fitness D. both smaller- and larger-than average phenotypes have the highest fitness E. the moon is in the Seventh House and Jupiter aligns with Mars
A
Event or Condition: During an extreme heat wave, plants with white flowers survive better. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
A
Event or Condition: Plants with purple flowers attract more insects, which pollinate the plants. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
A
Evolution on a small scale that can be observed today. Random changes in gene frequencies from generation to generation. A. Microevolution B. Macroevolution C. Macromutation D. Point mutation
A
Over time, humans have steadily increased their movements across the continents of the Earth. Which of the following results has most likely been derived from these movements? A. increased gene flow B. increased non-random mating C. increased genetic drift D. increased geographic isolation
A
Population bottlenecks are especially likely to increase: A. genetic drift B. gene flow C. the U.S. trade deficit D. random mating E. natural selection
A
Possessing similar characters because of common ancestry is called: A. homology B. homoplasy C. convergent evolution D. analogy C. being a copycat
A
Speciation: A. none of these statements is correct B. requires major genetic changes throughout the genome C. occurs in the same way in all organisms D. has never been documented in vascular plants E. requires a substantial amount of geographic separation between populations
A
The best definition of biological evolution is: A. a change in the genetic composition of a population B. a change in environmental conditions C. a change in the phenotype of an individual D. a change in the number of species in a habitat E. a change in the way you register for courses in Banner
A
The biological species concept places primary importance on: A. the degree of reproductive isolation B. the time since two species last shared common ancestry C. the degree of morphological differences D. the amount of polymorphism within a species E. the role of natural selection in changing characters
A
The male northern cardinal is much more brightly colored than the female because it sequesters much more of the red carotenoid pigment in its feathers. This statement is best described as: A. proximate causation B. ultimate causation C. totally fake news, because the female is actually more brightly colored than the male D. a true miracle E. a secret government conspiracy
A
The production of different-sized gametes between the sexes is called: A. anisogamy B. ambidexterity C. bicarbonate D. dianetics E. diplosaurus
A
What is the ultimate source of genetic variation? A. mutation B. genetic drift C. gene flow D. natural selection E. Amazon
A
When natural selection acts locally, gene flow will tend to: A. slow down the rate of adaptation B. speed up the rate of adaptation C. increase the rate of speciation D. reduce the mutation rate E. none of these answers is correct
A
Which condition is not required for a Hardy-Weinberg equilibrium in a population? A. differential reproductive success B. large population size C. isolation from other populations D. random mating E. all of these conditions are required to maintain a Hardy-Weinberg equilibrium
A
Which is a true statement concerning genetic variation? A. It must be present in a population in order to have evolution by natural selection B. It tends to be reduced when diploid organisms produce haploid gametes C. It is created by the direct action of natural selection D. A population with higher average heterozygosity has less genetic variation than a population with lower average heterozygosity E. It always leads to fitness differences among individuals
A
Which of these is not a prezygotic isolating mechanism? A. hybrid sterility B. gametic C. they are all prezygotic isolating mechanisms D. behavioral E. mechanical
A
Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is accurate? A. Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. B. Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. C. Each bird evolved a deeper, stronger beak as the drought persisted. D. The frequency of the strong-beak alleles increased in each bird as the drought persisted.
A
Which tree portrays the correct phylogenetic relationships among these representatives of the vertebrates? A. they both are correct because they represent the same genealogical relationships B. neither is correct C. the one on the left is correct D. the one on the right is correct E. It's a trick question! None of these organisms is actually a vertebrate!
A
a space (or a region of space) is divided into several regions, and then the same space-partitioning system is recursively applied to each of the regions thus created. A. Spatial subdivision B. population structure C. Founder effect D. Speciation
A
barriers to successful mating and fertilization. A. prezygotic B. polygamy C. polyandry D. postzygotic E. biological species
A
direct competition for mates between members of the same sex, usually male-male competition. A. Intra-sexual selection B. Intersexual selection C. Anisogamy
A
is a mode of negative natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype. A. Directional selection B. Stabilizing selection C. Disruptive selection
A
What situation most likely explains the occasional high frequency of certain inherited disorders among human populations established by a small population? A. founder effect B. nucleotide variability C. mutation D. bottleneck effect E. gene flow
A (The founder effect is genetic drift attributable to colonization by a limited number of individuals from a parent population) The founder effect is the reduction in genetic variation that results when a small subset of a large population is used to establish a new colony.
The essential difference between autopolyploidy and allopolyploidy is: A. the number of parent species involved B. the time scale involved in each type of speciaton C. one increases chromosome number, the other decreases it D. one is especially common among animals, the other is especially common among plants E. one is the good cop, the other is the bad cop
A Autopolyploidy appears when an individual has more than two sets of chromosomes, both of which from the same parental species. Allopolyploidy, on the other hand, occurs when the individual has more than two copies but these copies, come from different species.
Which of the following statements is accurate about an organ described as vestigial? A. It must be homologous to some feature in an ancestor. B. It must be analogous to some feature in an ancestor. C. It need be neither homologous nor analogous to some feature in an ancestor. D. It must be both homologous and analogous to some feature in an ancestor.
A Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs.
What is the type of allopatric (geographical) speciation in which gene-flow barriers arise without the requirement of dispersal? A. vicariant speciation B. sympatric speciation C. allopolyploidy D. quantum speciation E. autopolyploidy
A Dispersal occurs when a few members of a species move to a new geographical area, while vicariance occurs when a natural situation arises to physically divide organisms.
Pathogenic (disease-causing) bacteria found in many hospitals are quite resistant to antibiotics. This is best described as an example of: A. directional selection B. disruptive selection C. a non-genetic effect D. genetic drift E. sexual selection
A is a mode of negative natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype.
This figure illustrates: A. a vestigial character B. an extinct whale C. a primitive fish D. the fine work by surgeons at Alpine Orthopedic E. a valuable early painting by Picasso
A is an anatomical feature or behavior that no longer seems to have a purpose in the current form of an organism of the given species.
Genetic drift is best defined as: A. a change in allele frequencies due to sampling error B. a change in allele frequencies due to fitness differences C. the movement of individuals or their gametes between subpopulations D. mating between close relatives E. the expression of deleterious alleles
A variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.
is the result of differential survival and reproduction. It is the only mechanism of evolution that consistently causes a population to become better adapted to its environment. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
A (individuals who are more suitable to their environments, survive and reproduce similar traits)
How did mitochondria originate?
At some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion.
Event or Condition: Workers from a nearby greenhouse accidentally introduce white flower seed into this population's habitat. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
B
Evolution on a species scale that occurs over millions of years. Composes the history of life on earth. A. Microevolution B. Macroevolution C. Macromutation D. Point mutation
B
Male with more than one female. A. monogamy B. polygyny C. polyandry D. polygynandry
B
differences in attractiveness to the opposite sex, usually non-random choice by females A. Intra-sexual selection B. Intersexual selection C. Anisogamy
B
having but a single form, structural pattern, or genotype. A. reverse dimorphism B. monomorphic C. dimorphism D. plumage dimorphism
B
it equals fluctuations over time, as well as its subdivision in space. A. Spatial subdivision B. population structure C. Founder effect D. Speciation
B
natural selection arising through preference by one sex for certain characteristics in individuals of the other sex. A. natural selection B. sexual selection C. sexual dimorphism D. reverse dimorphism
B
results when alleles are transferred into or out of a population due to the migration of fertile individuals or their gametes. It can bring new alleles (beneficial, harmful, or neutral) into a population. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
B
You read about soapberry bugs and select the correct statement describing relative fitness in these individuals. A. A soapberry bug with high relative fitness feeds more successfully on fruits than do other bugs. B. A soapberry bug with high relative fitness has a relatively high number of offspring that survive to reproductive age. C. A soapberry bug with high relative fitness has more mates than other bugs.
B (Relative fitness is defined by the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals)
is any selective force or forces which push a population toward the average, or median trait. A. Directional selection B. Stabilizing selection C. Disruptive selection
B For example, the coats of a species of mice in a forest will all be the best color to act as camouflage in their environment.
Change in gene or chromosome number. A. Microevolution B. Macroevolution C. Macromutation D. Point mutation
C
Event or Condition: A person uproots the five closets plants, which all happen to have white flowers. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
C
Event or Condition: A storm kills many plants at random. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
C
Female with more than one male. A. monogamy B. polygamy C. polyandry D. polygynandry
C
Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent? A. gametic isolation B. temporal isolation C. behavioral isolation D. habitat isolation
C
Which of the following statements about genetic variation is accurate? A. Genetic variation arises in response to changes in the environment. B. Genetic variation is created by the direct action of natural selection. C. Genetic variation must be present in a population before natural selection can act upon the population. D. Genetic variation tends to be reduced when diploid organisms produce gametes.
C
Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by a resistant strain (MRSA). How can this best be explained? A. In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. B. S. aureus evolved to resist vaccines. C. Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. D. A patient must have become infected with MRSA from another community.
C
describes evolution due to chance events and causes unpredictable fluctuations in allele frequencies. May have a particularly significant effect in a small population, such as during a bottleneck or founder event. A. Natural selection B. Gene flow C. Genetic drift D. Alleles
C
is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. A. prezygotic B. Allopatric speciation C. sympatric speciation D. postzygotic E. biological species
C
is the systematic difference in form between individuals of different sex in the same species. For example, in some species, including many mammals, the male is larger than the female. A. natural selection B. sexual selection C. sexual dimorphism D. reverse dimorphism
C
produces a population that has two extreme versions of a trait as the dominant phenotype. A. Directional selection B. Stabilizing selection C. Disruptive selection
C
the existence of two different forms (as of color or size) of a species especially in the same population sexual ___________________. A. reverse dimorphism B. monomorphic C. dimorphism D. plumage dimorphism
C
where a single gene simultaneously affects multiple traits. A. Genetic drift B. Artificial selection C. Pleiotrophy
C
A species of mouse that is preyed on by owls (which can see color) at dawn and dusk varies in coat color between dark and light brown. Under which of the following conditions will NO evolution occur if climate change results in the soil color becoming darker? A. There is no way to make a prediction. B. Dark-colored mice are more likely to be eaten by owls. C. Light-colored mice produce more offspring than dark-colored mice. D. There is no variability in the genes that control coat color.
D
Both sexes with more than one partner. A. monogamy B. polygamy C. polyandry D. polygynandry
D
Change in a single nucleotide of a gene, can result in an amino acid change in the resulting polypeptide, or premature stop. A. Microevolution B. Macroevolution C. Macromutation D. Point mutation
D
Darwin used the phrase "descent with modification" to explain which of the following ideas? A. descent of all organisms from a single, ancient ancestor B. the unity of life C. the diversity of life D. both the unity and diversity of life
D
Perhaps the most common form of sexual dimorphism is that males are larger than females. The term "_____________ _________________" refers to a situation where this relationship is reversed. A. natural selection B. sexual selection C. sexual dimorphism D. reverse dimorphism
D
The effect of which Hardy-Weinberg condition is affected by population size? A. selection B. gene flow C. mutation D. genetic drift
D
Which of the following provides an example of a mechanical isolation as a prezygotic barrier (Anything that prevents mating and fertilization)? A. two species live in different habitats B. two species mate at different times C. two species share courtship activities D. two snails have shells that spiral in different directions
D
an individual or strain whose chromosome complement consists of more than two complete copies of the genome of a single ancestral species. A. prezygotic B. Allopatric speciation C. sympatric speciation D. autopolyploidy E. biological species
D
fertilization occurs, but hybrids are inviable or infertile or breakdown after only a few generations. A. prezygotic B. polygamy C. polyandry D. postzygotic E. biological species
D
defines a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring. According to that concept, a species' integrity is maintained by interbreeding within a species as well as by reproductive barriers between organisms in different species. A. prezygotic B. polygamy C. polyandry D. postzygotic E. biological species
E
A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10 are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population? A. In two generations, all the fish will be mottled. B. There is no way to predict the result. C. As the mottled fish are eaten, more will be produced to fill the gap. D. The ratios will not change. E. The proportion of mottled fish will increase over time.
E Natural selection: The mottled fish will tend to escape predation because they are camouflaged against the mottled lake bottom. The mottled fish will most likely produce more offspring.
Plants and fungi are more closely related to each other than either one is to animals. True or False
False
The genome-wide mutation rate in eukaryotes is typically between 10-6 and 10-9 (between one out of a million and one out of a billion cell divisions). True or False
False
Why are male cardinals red and not females?
This is because males of this species use their coloration to attract mates, with the reddest of birds having a higher success rate.
The original grouping of organisms in the Reptilia makes this a paraphyletic group. True or False
True
True or False? Evolution is the single unifying concept in biology.
True
True or False? Gene flow can both speed up and slow down adaptive change in populations.
True
True or False? Humans & chimpanzees have 95-98% sequence similarity at most genes but 9 inversion differences.
True
True or False? Mutation equals error in DNA replication or other alteration of the genome.
True
True or False? The biological species concept cannot be applied to fossils because the biological species concept uses reproductive isolation to define species.
True
True or False? The only process that produces adaptive change is natural selection.
True
The __________________ effect is an extreme example of genetic drift that happens when the size of a population is severely reduced. Events like natural disasters (earthquakes, floods, fires) can decimate a population, killing most individuals and leaving behind a small, random assortment of survivors.
bottleneck
Allele __________________ refers to how common an allele is in a population. It is determined by counting how many times the allele appears in the population then dividing by the total number of copies of the gene.
frequency
Describes a population that is not evolving. Hardy-Weinberg equilibrium never happens in ____________, but is a useful baseline for scientists to base their observations of populations on.
nature
The immediate or short term cause of something is known as ______________ causation, and evolutionary biology helps us understand why something exists the way it does in the first place - and not some other way. This is known as _____________ causation.
proximate ultimate
