Bio 171 Exam 2 Quizzes

A population is composed of 1000 individuals, of whom 500 are DD, 140 are Dd, and 360 are dd. What is the frequency of the d allele? 0.06 0.60 0.50 0.43 0.36 0.40

0.43

In gorillas, the ability to roll the tongue is under the control of 1 gene. The R allele, which confers tongue-rolling ability, exhibits complete dominance over the r allele. In a population of 1000 gorillas in Uganda, there are 575 gorillas who can roll their tongues. Assuming Hardy Weinberg Equilibrium, what is the frequency of heterozygotes in this population? 0.425 0.121 0.575 0.500 0.455 0.348 0.652

0.455

In a hypothetical population of 1000 frogs there exists a gene, D, with two alleles (D and d). 280 of the frogs are homozygous dominant (<i>DD</i>), and 220 are homozygous recessive (<i>dd</i>). What is the frequency of heterozygotes in the population? 0.0 0.50 0.22 0.28

0.50

A population is in Hardy-Weinberg Equilibrium with respect to a gene, "yellow," which has 2 alleles, y and Y. Green (coded for by Y, the wild type allele) is completely dominant. Yellow (coded for by y, the less frequent allele) is recessive. The frequency of the yy homozygote is 0.09. The frequency of the Y allele is ____; the frequency of the y allele is ____; the frequency of the YY homozygote is ___; the frequency of the Yy heterozygote is ___. 0.91, 0.09, 0.82, 0.15 0.7, 0.3, 0.49, 0.42 0.3, 0.7, 0.0, 0.91 It is impossible to determine this from the information in the question 0.3, 0.3, 0.01, 0.01

0.7, 0.3, 0.49, 0.42

Given equal probabilities of the birth of a boy or girl, what is the probability that a group of four siblings includes all boys? All girls? All boys or all girls? 1/16; 1/16; 1/64 1/8; 1/16; 3/8 1/16; 1/8; 3/8 1/16; 1/16; 1/8

1/16; 1/16; 1/8

Suppose that 75% of chickadees (a bird) have a head crest and must therefore have at least one copy of the dominant H allele. Assuming that this population is in Hardy Weinberg Equilibrium for this gene, what percentage of the population must be homozygous dominant for this trait? 0.025% 0.5% 75% 50% 25% 2.5%

25%

If there are 100 individuals in a population and 20 are homozygous for B, 60 are heterozygous, and 20 are homozygous for b, what is the allele frequency of B? 20% 40% 50% Allele frequency cannot be calculated from this information. 80%

50%

Which of the following examples describes the population where genetic drift is most likely to have the largest effects on allele frequencies? Cackling geese used to be considered a subspecies of Canada geese, but now Cackling geese are a unique species. Cackling Geese are small with a shorter bill than Canada geese. A few mockingbirds are blown from mainland South America to distant islands. The mockingbirds colonize the islands and have a different set of allele frequencies than the mainland population. A population of songbirds is reduced by 50% due to low food availability during a harsh winter. Black bears and grizzly bears interbreed (but rarely) where their geographic ranges overlap. Monarch butterfly populations decrease because overwintering grounds in Mexico are deforested.

A few mockingbirds are blown from mainland South America to distant islands. The mockingbirds colonize the islands and have a different set of allele frequencies than the mainland population.

What would you expect to decrease in frequency more rapidly in a population: a gene with no impact on survival or a gene with a negative impact on survival? Why? A gene with no impact on survival; decreasing its frequency is advantageous A gene with no impact on survival; decreasing its frequency is deleterious A gene with a negative impact on survival; decreasing its frequency is deleterious A gene with a negative impact on survival; decreasing its frequency is advantageous

A gene with a negative impact on survival; decreasing its frequency is advantageous

Which of the following populations is most likely to be in Hardy-Weinberg equilibrium with respect to a gene, Floppy? Floppy has two alleles "F" and "f". Assume f(F) = p and f(f) = q. A population for which p+q = 1 and p2 + 2pq + q2 = 1. A population for which p=0.5, q = 0.5, and the frequency of the heterozygote is 0.5. A population for which p=0.5, and the frequency of the FF homozygote is 0.5. A population in which females whose fathers had FF or Ff prefer to mate with males with FF or Ff, while females whose fathers had ff, prefer to mate with males with ff. A population founded by a few individuals, blown to Hawaii from mainland North America 20 generations

A population for which p=0.5, q = 0.5, and the frequency of the heterozygote is 0.5.

A particular gene in a given population of individuals has two alleles, A and a. The frequency of the A allele equals the frequency of the a allele. What are the expected genotype frequencies, assuming the population is in Hardy-Weinberg equilibrium? A = 0.5, a = 0.5 AA = 0.25, Aa = 0.50, aa = 0.25 AA = 0.5, aa = 0.5 The answer cannot be determined because the allele frequencies are not provided.

AA = 0.25, Aa = 0.50, aa = 0.25

Which of the following statements is TRUE regarding molecular clocks? Molecular clocks correlate the genetic divergence between specific species to the time back to their evolutionary "separation." Pseudogenes usually have very fast molecular clocks. Negative selection can play a role in the "rate" of a molecular clock. All of these choices are correct. Rates of molecular clocks can be very different for different genes.

All of these choices are correct.

Which of the following is a PREDICTION of the Hardy-Weinberg Principle, assuming a very large population with random mating after one generation and no evolutionary processes affecting a given gene? The frequency of the homozygotes in the population will be p^2+ q^2. The genotypic frequencies will not change. All of these statements are valid predictions of the Hardy-Weinberg principle The allelic frequencies of this gene will remain more or less the same.

All of these statements are valid predictions of the Hardy-Weinberg principle

When calculating the allele frequency for allele A in a population, why do you multiply the number of individuals who are homozygous for A by 2? Because each individual homozygous for A has two copies of the allele. Because individuals homozygous for A will produce twice as many offspring. Because there are always twice as many homozygous individuals as heterozygous individuals. Because individuals homozygous for A will be twice as likely to survive. Because if A is dominant, it will show up twice as much.

Because each individual homozygous for A has two copies of the allele.

A cattle breeder selects the largest males for breeding with the largest females. Assume that the trait for body size is heritable. This is an example of: Directional natural selection Directional artificial selection Disruptive selection Balancing selection Stabilizing selection

Directional artificial selection

Please review lecture 8 before completing this question. In a population, a gene, Tough, has 2 alleles. "T" confers the dominant phenotype (tough), and individuals with the dominant phenotype produce, on average, 10 offspring. "t" confers the recessive phenotype (brittle), and individuals with the recessive phenotype produce, on average, 100 offspring. Given this we know that: None of these answers is valid, because we do not know the fitness of the heterozygote Stabilizing selection is happening Balancing selection is happening Directional selection is happening Disruptive selection is happening

Directional selection is happening

Gene flow between two populations of organisms, acting alone, cannot change allele frequencies in a population. Other evolutionary processes are required to change allele frequencies. True False

False

True or false? Inbreeding results in a change in allele frequencies in a population. False True

False

You would expect similar species with a different number of chromosomes to be genetically compatible and therefore able to reproduce. True False

False

Watch the video "Birth and Death of Genes" before answering this question. Which of the following mutation types definitely occurred in the loss of functional hemoglobin protein in icefish? Noncoding mutation Frameshift mutation Gene duplication Synonymous mutation

Frameshift mutation

Which of the following statements about evolutionary processes is ACCURATE? Genetic drift and gene flow can increase or decrease the mean fitness of the population. Balancing natural selection reduces levels of genetic variation in the population. Genetic drift and gene flow both reduce levels of genetic variation between populations. Mutations alone can significantly change allele frequencies in a population of animals. Stabilizing and directional sexual selection reduce levels of genetic variation and change the average value of the selected trait.

Genetic drift and gene flow can increase or decrease the mean fitness of the population.

What is the correct sequence of events listed? Biologists think that speciation generally occurs when: (I) mutation leads to genetic divergence between the two populations (II) a barrier prevents gene flow between two populations of the same species (III) pre-zygotic or post-zygotic isolating barriers evolve (IV) selection or genetic drift leads to genetic differences among the two populations.

II, I, IV, III

Why is Hardy-Weinberg such a valuable tool when examining populations? It enables us to identify if a population is evolving. It enables researchers to determine if an allele is dominant or recessive. It enables researchers to identify beneficial mutations. It enables us to predict phenotype frequencies.

It enables us to identify if a population is evolving.

What does it mean to say that an allele is "fixed" in the population? It has been repaired by typical mechanisms in the cell. It is an indication of no genetic variation at that locus in the population. It is an indication that locus cannot undergo mutation. It is an indication of high genetic variation at that locus in the population. It is an indication of low genetic variation at that locus in the population.

It is an indication of no genetic variation at that locus in the population.

A population has a gene with 2 alleles, G and g. The frequency of the G allele is 0.8. The frequency of the g allele is 0.2. What is the frequency of the GG genotype? 0.16 0.64 It is impossible to determine this from the information in the question 0.45 0.32 0.04

It is impossible to determine this from the information in the question

Which of the following types of inheritance violate Mendel's law of independent assortment? Sex linkage Linkage between alleles on the same chromosome Epistasis Mitochondrial inheritance Codominance

Linkage between alleles on the same chromosome

Which of the following statements best describes the difference between artificial and natural selection? Natural selection generally acts without the input of humans whereas artificial selection requires human input. Natural selection has never been observed but artificial selection has been observed in many species that humans have domesticated. Natural selection works on all species, but artificial selection only applies to laboratory-raised species. Artificial selection has produced many of the most delicious food items for humans; natural selection has not. Natural selection is limited to morphological traits and artificial selection is not.

Natural selection generally acts without the input of humans whereas artificial selection requires human input.

Which of the following statements best describes the difference between artificial and natural selection? Natural selection is limited to morphological traits and artificial selection is not. Natural selection has never been observed but artificial selection has been observed in many species that humans have domesticated. Natural selection works on all species, but artificial selection only applies to laboratory-raised species. Natural selection generally acts without the input of humans whereas artificial selection requires human input. Artificial selection has produced many of the most delicious food items for humans; natural selection has not.

Natural selection generally acts without the input of humans whereas artificial selection requires human input.

A research team studies a large Eastern Milk Snake population in a metropark near Ann Arbor. In these snakes, gene T is one gene that affects the color pattern of the snake's body. In 2004, the research team sampled a large number of snakes and determined the genotypes of the snakes for the T gene. They find the following genotype frequencies: TT = 0.16 Tt = 0.20 tt = 0.64. In 2005, the researchers re-sampled the population and determined that the frequency of the T allele is 0.4. One generation has passed. Is the population in Hardy Weinberg Equilibrium for the T gene? No, because the allele frequencies in 2004 do not match the allele frequencies in 2005. Yes, because the square root of 0.16 = 0.4. No, because the TT genotype is likely being selected against in this population. No, because there is selection occurring AND because the allele frequencies in 2004 do not match the allele frequencies in 2005. Yes, because the genotype frequencies all add up to 1.

No, because the allele frequencies in 2004 do not match the allele frequencies in 2005.

Which of the following is/are true about the Hardy-Weinberg Principle? (I) If Hardy-Weinberg equilibrium is observed at one gene, it implies that there is no selection on the entire genome. (II) A population that is increasing in size will never reach Hardy-Weinberg equilibrium. (III) If a population has 10 individuals, and the genotype frequencies at a particular locus are freq(AA) = 0.25, freq(Aa)=0.5, freq(aa) =0.25, then this information alone is enough to allow us to conclude that this population is in Hardy-Weinberg equilibrium. II only None of these are true. II and III I and II III only

None of these are true.

The ear tuft allele (T) in chickens is autosomal dominant, and is lethal in the homozygous state. In other words, homozygous dominant (TT) embryos do not hatch from the egg. In a population of 10,000 chickens, 2,000 have no ear tufts (tt) and 8,000 have ear tufts (Tt). What are the frequencies of the normal versus ear tuft alleles in this population? T = 0.40; t = 0.60 T = 0.60; t = 0.40 T = 0.66; t = 0.33 T = 0.33; t = 0.66 T = 0.20; t = 0.80 T = 0.80; t = 0.20

T = 0.40; t = 0.60

If Mendel based his data only on two traits, and the genes influencing those traits were linked and located close together on the same chromosome, which of his laws would he not have been able to resolve? The Law of Segregation The Law of Independent Assortment

The Law of Independent Assortment

What is the result of a mutation that occurs in somatic cells? The mutation may be expressed in the individual, but will not be passed along to its offspring. There will never be any visible effect. The mutation will be passed along to the organism's offspring. The mutation will be deleterious. The mutation will prevent all reproduction.

The mutation may be expressed in the individual, but will not be passed along to its offspring.

Please review lecture 8 before completing this question. In a population, a gene, Tough, has 2 alleles. "T" confers the dominant phenotype (tough), and individuals with the dominant phenotype produce, on average, 10 offspring. "t" confers the recessive phenotype (brittle), and individuals with the recessive phenotype produce, on average, 100 offspring. Given this: The RELATIVE fitness of individuals with the "Tt" phenotype is 0.1, while the relative fitness of individuals with the "tt" phenotype is 1. The fitness of individuals with the heterozygote's phenotype is lower than that of individuals with the homozygote's phenotype. The RELATIVE fitness of individuals with the "TT" phenotype is 10, while the relative fitness of individuals with the "tt" phenotype is 100. The fitness of individuals with the "TT" phenotype is 1, while the fitness of individuals with the "tt" phenotype is 0.1. The RELATIVE fitness of individuals with the "Tt" phenotype is higher than that of individuals with the "tt" phenotype.

The RELATIVE fitness of individuals with the "Tt" phenotype is 0.1, while the relative fitness of individuals with the "tt" phenotype is 1.

Positive selection is acting on an allele of a SNP. Given this, which is most likely? The population is in Hardy-Weinberg equilibrium with respect to this SNP. The SNP is in a non-coding region of DNA that has no effect on phenotype. The SNP is located within a gene that affects phenotype. The SNP has multiple alleles (more than 2 alleles) in the population. The SNP is on a sex chromosome, thereby affecting sexual selection.

The SNP is located within a gene that affects phenotype.

One type of natural selection is balancing selection. One scenario that can lead to balancing selection is when a heterozygote phenotype has a fitness advantage. Which of the following are reasonable predictions of balancing selection due to heterozygote advantage? Assume that after 10 generations under the balancing selection, the f(A1) = 0.5, where "A1" is one of two alleles of a given gene; "A2" is the other allele. The genotype, A1A2, will become fixed in the population. The f(A2) will increase, while the f(A1) will decrease. One of the two alleles will become fixed in the population. The f(A1A2) will increase, while the f(A1A1) and f(A2A2) will decrease. The f(A1) will remain roughly the same over the following generations.

The f(A1) will remain roughly the same over the following generations.

When a founder population colonizes a new habitat or when a population undergoes a bottleneck, genetic drift can dramatically change allele frequencies. This dramatic change happens because: The population size is very small During these dramatic events, only the strongest individuals can survive, which means that natural selection is acting very strongly Chance events happen more frequently after disasters, such as those that cause bottlenecks The decrease in population size must mean that some individuals can reproduce and others cannot, because of their phenotypes Genes drifted from one population to another, for example, from the mainland to an island population

The population size is very small

Which of the following statements is TRUE regarding the molecular clock of hemoglobins? The molecular clock of hemoglobins could be considered to be at a "standstill," as mutations in hemoglobin genes are usually not affected by natural selection. Given the robust action of negative selection on deleterious mutations in hemoglobin genes, the molecular clock of hemoglobins is much slower than that of histones. Given the high rate of mutations that occur in the DNA coding regions of hemoglobin genes, the molecular clock of hemoglobins is much faster than that of pseudogenes. The rate of the molecular clock of hemoglobins is in between that of pseudogenes and histones.

The rate of the molecular clock of hemoglobins is in between that of pseudogenes and histones.

Why do histone genes have a very slow molecular clock? Histone genes simply do not have the same rate of mutations. DNA repair mechanisms do not function for histone genes, so mutations accumulate quickly. The structure of the histone gene must be conserved for DNA to function properly. Cells have more histone genes than any other kind of gene. Following mutations, DNA repair mechanisms function more readily with histone genes.

The structure of the histone gene must be conserved for DNA to function properly.

If an assumption for the Hardy-Weinberg equation is violated, what does this mean? This means that mutations are increasing in frequency in the population. This means that the population is adapted to its environment. This means an allele is fixed in the population. This means the allele frequencies or genotype frequencies are changing.

This means the allele frequencies or genotype frequencies are changing.

Females are generally "choosier" than males about who they mate with. False True

True

True or false? Genetic drift, acting alone, can change allele frequencies in a population. True False

True

In one set of experiments, Calvin Bridges crossed white-eyed female fruit flies with red-eyed males. Some of the offspring were white-eyed females. These individuals, he demonstrated, had the genotype ____________, which occurred because of ____________ during meiosis. (Hint: see Figure 17.6) XXO; independent assortment XXY; nondisjunction XXY; random segregation XXX; nondisjunction

XXY; nondisjunction

One oak tree produces two kinds of leaves: large with shallow lobes and narrow with deep lobes. If this variation in leaf shape is based solely on the ecological condition of amount of sunlight exposure and there is no genetic difference between leaves that express either of the two forms, then this is: a gene by environment interaction the result of maternal inheritance the result of epistasis the result of a mutation the result of multiple alleles

a gene by environment interaction

Which of the following would be good examples of genotype-by-environment interactions? Select all that apply. two different strains of corn that differ in height due to genotype a line of dairy cows that increases milk yield in relation to amount of food the cows receive two different mutants of mice that share similar fat metabolism abilities a strain of mutant mice that becomes obese regardless of amount of food the mice receive a line of chickens whose eggshells are extra thick regardless of food type a strain of corn whose yield varies with the amount of nutrients in the soil

a line of dairy cows that increases milk yield in relation to amount of food the cows receive a strain of corn whose yield varies with the amount of nutrients in the soil

Which of the following would be considered an advantageous mutation? a mutation that increases an organism's ability to find food a mutation that causes increased susceptibility to a disease a mutation that makes an individual more visible to predators a mutation that changes hair color in humans a mutation that decreases the offspring's chance of survival

a mutation that increases an organism's ability to find food

What kind of mutation has no effect on an organism's ability to survive or reproduce? a neutral mutation a deleterious mutation an advantageous mutation an adaptive mutation

a neutral mutation

What kind of mutation has no effect on an organism's ability to survive or reproduce? an advantageous mutation a neutral mutation an adaptive mutation a deleterious mutation

a neutral mutation

If an allele increases in frequency in a large population, it likely has a negative impact on survival. no impact on survival. a positive impact on survival.

a positive impact on survival.

Blue-footed boobies are birds with blue feet whereas red-footed boobies are birds with red feet. During courtship, males of both booby species display their feet to potential partners. If a red-footed male displays his feet to a blue-footed female, and the female declines to mate with him, we can conclude that the mismatch in foot color is an example of a vicariance event. hybrid inviability. mechanical isolating barrier. a post-zygotic barrier to reproduction. gametic isolation. speciation. a pre-zygotic barrier to reproduction.

a pre-zygotic barrier to reproduction.

You are a biologist on a trip to an island in the South Pacific. While there, you are allowed to collect DNA samples from a local species of tortoise that resembles a species seen on a nearby continent. If your DNA analysis also indicates the two species are highly related, you might conclude that this was an example of _______________ through ________. sympatric speciation; vicariance sympatric speciation; dispersal allopatric speciation; vicariance allopatric speciation; dispersal

allopatric speciation; dispersal

In 2001, a small population of about 12 wolves lived on Isle Royale, an island in Lake Superior. Scientists were interested in the impact that isolation had on this population of wolves, so they tracked the wolves' genetics over several generations. Researchers noted that inbreeding was negatively impacting this population's genetic diversity. What did researchers likely observe in the data when they looked at a single gene with just two alleles? an increase in heterozygosity resembling the results of balancing selection a decrease in the recessive allele frequency but an increase in the recessive genotype frequency a population that is in Hardy-Weinberg equilibrium uniform allele and genotype frequencies generation after generation an increase in the number of homozygous individuals, but a stable allele frequency an increase in the dominant allele frequency, but a stable genotype frequency

an increase in the number of homozygous individuals, but a stable allele frequency

Sympatric speciation often requires the action of ____________ selection acting against intermediate phenotypes. stabilizing disruptive directional balancing artificial

disruptive

2002 to 2003 was a very cold winter in southeastern Michigan, with temperatures falling much below the typical winter averages. Many insects died a result of the cold winter, including many Asian lady beetles (Harmonia axyridis). These beetles normally hibernate (in the adult stage) during the winter months. As Asian lady beetles emerged from hibernation in the spring of 2003, you noticed that many large-bodied beetles had survived, presumably because they had fat reserves that sustained them through the long winter. Surprisingly, some very small beetles had survived too, apparently because they could squeeze into the cracks in people's houses and stay warm. The type of selection experienced by these lady beetles over the winter could be best described as balancing sexual selection directional natural selection balancing natural selection disruptive natural selection stabilizing natural selection

disruptive natural selection

Recall the example of different ladybug species described in the text, which each feed on a different species of plant. If two such species inhabit the same types of plants but in different locations (i.e., one near the base of the plant and the other on the uppermost leaves), these species would be considered to be _____ separated. both temporally and ecologically temporally ecologically energetically

ecologically

A drawback of the biological species concept is that it CANNOT be applied to: highly polymorphic species. plants, which do not physically come in contact with each other when transferring gametes the way that animals do. All of these choices are correct. populations of a single species living in different places. extinct and asexual organisms.

extinct and asexual organisms.

A beneficial mutation is more likely to get fixed in a population through genetic drift than is a deleterious mutation. true false

false

A population that is IN Hardy-Weinberg equilibrium is evolving. false true

false

On a hike through the forest, you notice a population of 100 flowering plants that all look identical (phenotypic clones). They span an area of approximately 100 square meters but there are other populations of this species nearby. You take some representatives from one corner of their distribution back to the lab, sequence their DNA and conclude that they are also genetic clones. True or false: This population can ONLY evolve through genetic drift. false true

false

True or false: Genetic differences are always more important than environmental differences for determining phenotypic outcomes. false true

false

Watch the video "Birth and Death of Genes" before answering this question. True or False? "If the temperature of the environment where the icefish are living were to rise to 5°C, the frequency of the antifreeze gene in the population would likely increase." false true

false

A population that exhibits only one allele at a particular gene is: undergoing genetic drift. experiencing natural selection. in Hardy-Weinberg equilibrium. fixed for that allele. undergoing evolution.

fixed for that allele.

As a biologist, you are studying a population of moles. In the course of your research, you identify a nearby population that occasionally comes into contact and interbreeds with your study population. What best describes the evolutionary process at work? artificial selection genetic drift mutation natural selection gene flow

gene flow

The concept of a molecular clock allows a population geneticist to estimate what? how frequently beneficial mutations will appear in a population how quickly mutations are occurring in all species how large a population is how long two populations of the same species have been separated

how long two populations of the same species have been separated

Hammer-head bats are a species of African fruit bats. During the breeding season, males gather in mating arenas, where they display to females who pass through and assess males before selecting individuals with which to mate. This is an example of ____________-sexual selection. inter intra

inter

The biological species concept states that species are actually or potentially _____ populations that are reproductively isolated from other such groups. physically similar interbreeding genetically identical naturally selected cohabitating

interbreeding

Northern elephant seals (Mirounga angustirostris) come up on a beach during breeding season. Males arrive first and establish a territory by posturing and fighting with other males. The posturing and fighting behaviors are probably the result of ____________. directional natural selection intrasexual selection intersexual selection diversifying natural selection genetic drift gene flow between two separate populations of elephant seals

intrasexual selection

Instantaneous speciation: (select all correct choices) is relatively common in plants but not in animals. none of these is, by definition, a type of sympatric speciation. often involves the multiplication of chromosome sets, or polyploidy. is typically caused when hybridization between species produces fertile, viable offspring that are reproductively isolated from both parental species.

is relatively common in plants but not in animals. is, by definition, a type of sympatric speciation. often involves the multiplication of chromosome sets, or polyploidy. is typically caused when hybridization between species produces fertile, viable offspring that are reproductively isolated from both parental species.

Genetic variation in a population refers to which of the following? multiple alleles within a gene pool multiple genes within a genome multiple phenotypes with the same genotype multiple individuals breeding together multiple offspring with advantageous mutations

multiple alleles within a gene pool

The process by which sympatric speciation might occur would most likely be the result of: natural selection. convergent evolution. adaptive radiation. vicariance.

natural selection.

Some genes have a slower molecular clock due to _____ selection, which eliminates harmful alleles. neutral negative positive disruptive beneficial

negative

You find that a wild population of antelope is not in Hardy-Weinberg equilibrium for a particular gene. From this information alone, can you determine which evolutionary process is acting on the antelope population? yes no

no

You have spent time working with a population of beetles. Males range in size from 2-6 cm in length. You realize that the females only mate with males that measure less than 3 cm long. If you measured allele frequencies at a single locus that contributes to overall length, would you expect this population to be in Hardy-Weinberg equilibrium for the body length gene from one generation to the next? no yes

no

Consider two isolated populations of lady slipper orchids. These populations are hundreds of miles apart; one is in Northern Minnesota and the other is in the Upper Peninsula of Michigan. They are so far apart that pollinators cannot possibly transfer pollen between the two populations. Based on this information, you expect there to be _________________ between these two populations. a low but consistent level of gene flow active migration inbreeding a high level of gene flow no gene flow

no gene flow

Unlike the biological species concept, the morphospecies concept relies on: phenotype. behavior. physiology. offspring.

phenotype.

In northern elephant seals, body size is determined by at least 8 genes. Males compete for territories on the beach and larger males are more likely to win fights. In this example, inheritance of body size is ________________, intrasexual selection on male body size is ____________________, which results in _______________ in mean male body size in subsequent generations. pleiotropic / directional / increases epistatic / disruptive / decreases polyallelic/ stabilizing/ no change polygenic / directional / increases polygenic / disruptive / decreases

polygenic / directional / increases

Genetic drift has an especially significant effect in what kind of populations? populations with high genetic variability populations that are large populations that are small populations that are subject to natural selection populations that are migrating

populations that are small

You observe two groups of freshwater fish that spawn at the same time of the year and in the same pond. After females lay their eggs on the pond bottom, males of both species attempt to fertilize them. After some investigation you realize that sperm from both species fertilize the eggs, but embryonic development stops shortly after fertilization when the eggs are fertilized by one species of males, but not by the other. This is an example of ______- zygotic reproductive isolation between the two species. post pre

post

You observe two groups of birds that appear to be closely related. Males from the first group have bright red stripes on their tail feathers that they display in a courtship dance preceding mating. Females only respond to color patterns exhibited by males of their species. This is an example of ______- zygotic reproductive isolation between two species. post pre

pre

Genetic drift is the ____________ in allele frequencies from generation to generation and is especially important in ____________ populations. none of these random change; large change due to selection; small change due to selection; large random change; small

random change; small

The differential reproductive success of individuals who carry a particular allele in a given environment is called ____________. fixation selection evolution migration genetic drift

selection

The Biological Species Concept is least useful for identifying: plant species. species in marine environments. species represented by fossils. animal species.

species represented by fossils.

Ferrets are unable to withstand long periods of cold weather and must hibernate throughout much of the winter. Hibernating sites are in short supply, and ferrets only survive if they can find holes in trees that fit their body size. Very small tree holes are in short supply because they are generally colonized by stinging wasps that chase away ferrets. Very large tree holes are in short supply because they are colonized by snakes that eat ferrets. The limiting supply of tree holes should act as balancing selection on ferret body size disruptive selection on ferret body size stabilizing selection on ferret body size sexual selection on ferret body size directional selection on ferret body size

stabilizing selection on ferret body size

Two populations that have been separated from each other for a long period of time will have: no differences between their genetic sequences. limited differences between their genetic sequences. no similar genetic sequences. small differences in phenotype but identical genotypes. substantial differences between their genetic sequences.

substantial differences between their genetic sequences.

Cicadas are large insects that live underground for the majority of their lives. In North America, species emerge from the ground only every 13 or 17 years to mate. Because of differences in breeding times, two species of cicada do not mate at the same time and so cannot produce hybrids. The reproductive isolating mechanism at work is: inbreeding depression hybrid inviability temporal isolation behavioral isolation mechanical isolation

temporal isolation

You are studying reproduction in a species of frog. Imagine there was a mistake in meiosis such that ALL the gametes produced by two individuals are diploid rather than haploid. Two of these gametes fuse. This zygote is: tetraploid (4n) diploid (2n) haploid (n) octoploid (8n)

tetraploid (4n)

Choose one single BEST answer to complete this sentence. The frequency of recombination during meiosis is a function of: the distance between genes: the closer the genes are, the more frequent the recombination between them. the alleles on the genes; recombination happens less frequently among recessive alleles. whether or not the genes are sex-linked; Y chromosomes recombine much more frequently than do the autosomes. whether or not the genes are sex-linked; X chromosomes recombine much more frequently than do autosomes. the distance between genes: the farther apart the genes are, the more frequent the recombination between them.

the distance between genes: the farther apart the genes are, the more frequent the recombination between them.

What is the hypothetical long-term result of different mutations accumulating in different populations? fixation of the same alleles in both populations the extinction of one population decreased genetic isolation the evolution of different species merging the populations through migration

the evolution of different species

Which of the following is the best measure of an organism's fitness? the number of mutations it acquires in its lifetime its size, compared to other members of the same species the number of surviving fertile offspring it produces the amount of care it receives from its parents how long it lives

the number of surviving fertile offspring it produces

The phrase "Modern Synthesis" refers to: the synthesis of Darwin's ideas about natural selection and modern DNA sequencing technology. the synthesis of Darwin's ideas about natural selection and Mendelian genetics. the synthesis of Darwin's ideas about evolution with Malthus' ideas about population growth. the synthesis of Darwin's and Wallace's independently developed ideas about natural selection and adaptation. All of the answer options are correct.

the synthesis of Darwin's ideas about natural selection and Mendelian genetics.

The allele frequency of all the alleles of a gene present in the population must add up to 1. (Allele frequencies of all alleles for a gene must always add up to be 1, which is 100% of the population.) true false

true

True or false: When studying phenotypic variations due to the environment, it is necessary to compare organisms with identical genotypes. In addition, it is necessary to use identical environments when studying variation in genotypes. true false

true

While in South America, you come across what you think are two species of birds in the same location. They are nearly identical aside from their color. After years of observation, you conclude that the birds eat similar diets and share similar behaviors, but do not reproduce with each other. These groups of birds appear to be an example of ____________. two different species because they live in different areas two different species on the basis of reproductive behavior a single biological species

two different species on the basis of reproductive behavior