Genetics CH. 18 Achieve Quiz Questions

The amount that risk increases depends on two factors: a. (1) the frequency of the deleterious allele in the population and (2) the degree of inbreeding. b. (1) the frequency of the deleterious allele in the population and (2) generation time. c. (1) the population size and (2) generation time. d. (1) the population size and (2) the degree of inbreeding.

a. (1) the frequency of the deleterious allele in the population and (2) the degree of inbreeding.

A researcher is studying a population of organisms in which inbreeding occurs frequently. He knows that for two alleles, C and c, p and q are 0.75 and 0.25. If F in this population is 0.25, what will be the frequency of cc homozygotes in this population? a. 0.16 b. 0.47 c. 0.66 d. 0.28

a. 0.16

A researcher is studying a population of organisms in which inbreeding occurs frequently. He knows that for two alleles, C and c, p and q are 0.75 and 0.25. If F in this population is 0.25, what will be the frequency of cchomozygotes in this population? a. 0.16 b. 0.47 c. 0.66 d. 0.28

a. 0.16

In a population of 23 with an inbreeding coefficient of 0.2, calculate Ft+2. a. 0.234 b. 0.217 c. 0.1957 d. 0.0217

a. 0.234

A researcher is studying a population of organisms in which inbreeding occurs frequently. He knows that for two alleles, C and c, p and q are 0.75 and 0.25. If F in this population is 0.25, what will be the frequency of heterozygotes in this population? a. 0.28 b. 0.47 c. 0.16 d. 0.66

a. 0.28 FC/c = 2pg − 2pqF = 2(0.75)(0.25) − 2(0.75)(0.25)(0.25) = 0.375 − 0.09375 = 0.28.

When there is complete inbreeding, F is equal to _____. a. 1 b. 2 c. 0 d. 0.5

a. 1

Consider a population with the size N, in the generation t + 1. What is the probability that the second allele we pick will be a different copy from the first allele? a. 1 - 1/(2N) b. (1/2)n c. N − 1 d. 1/(2N)

a. 1 - 1/(2N)

What is the probability that two alleles in an offspring from a mating between two half-siblings are identical by descent? Assume the common ancestor of the parents has an inbreeding coefficient of 0. a. 1/8 b. 1/16 c. 1/4 d. 1/2

a. 1/8

Inbreeding violates the random mating assumption of the Hardy-Weinberg law. Which of these represents the inbreeding modification for heterozygotes using the Hardy-Weinberg law? a. 2pq − 2pqF b. p2 + 2pqF c. p2 − 2pqF d. q2 + 2pqF

a. 2pq − 2pqF - modified Hardy-Weinberg Law for inbred heterozygotes.

A researcher is studying a population of robins in his town. He is specifically interested in a single locus with two alleles, Q and q. He samples 20 robins. What will be the total number of alleles? a. 40 b. 10 c. 20 d. 80

a. 40

A researcher is studying two linked loci in a population of rabbits. In the current generation, these loci demonstrate a D of 0.30. If the researcher knows that the recombination frequency between these two loci is 0.25, what can he conclude about the D value of these loci in the next rabbit generation? a. D = 0.23 b. D = 0.30 c. D = 0.075 d. D = 0

a. D = 0.23 - D1 = D0(1 − r) = 0.30(1 − 0.25) = 0.225.

_____ and _____ are examples of negative assortment mating. a. Self-incompatibility; major histocompatibility complex (MHC) b. Self-pollination; isolation c. Self-pollination; major histocompatibility complex d. Self-incompatibility; isolation

a. Self-incompatibility; major histocompatibility complex (MHC)

Microsatellites are powerful loci for population genetic analysis for what reason? a. The number of alleles at a microsatellite is often very large. b. Microsatellites have a low mutation rate. c. Microsatellites have a lower level of variation. d. There are a minimal number of microsatellites in most genomes.

a. The number of alleles at a microsatellite is often very large.

Selection can take several forms that affect genetic variation in different ways. Match the types of selection with the correct phrase. 1. positive selection 2. purifying selection 3. balancing selection a. increases the frequency of an advantageous allele b. maintains a high frequency of an allele by selecting c. different alleles are maintained in the population

1, a; 2, b; 3, c

You have sampled a population of toads over three years for the BrrP locus. The first year, you calculated these allele frequencies: B = 0.75 and b = 0.25. The second year, you determined that B = 0.66 and b = 0.34. What can you conclude from these data? a. This toad population is not in Hardy-Weinberg equilibrium and not all of the assumptions of the Hardy-Weinberg law are valid for it. b. This toad population is in Hardy-Weinberg equilibrium and not all of the assumptions of the Hardy-Weinberg law are valid for it. c. This toad population is in Hardy-Weinberg equilibrium and all of the assumptions of the Hardy-Weinberg law are valid for it. d. This toad population is not in Hardy-Weinberg equilibrium and all of the assumptions of the Hardy-Weinberg law are valid for it.

a. This toad population is not in Hardy-Weinberg equilibrium and not all of the assumptions of the Hardy-Weinberg law are valid for it. - The allele frequencies are not remaining constant between generations, so the toad population is not in Hardy-Weinberg equilibrium. Because the population is not in equilibrium, the associated assumptions are not applicable.

The South African Afrikaner population is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of the gene that causes Huntington disease, because the gene was represented with unusually high frequency in the original Dutch colonists. This is an example of a population _____. a. bottleneck b. genetic admixture c. discovery panel d. gene pool

a. bottleneck

The principles of population genetics can be used to address issues in several fields. Which of these is NOT an example of this? a. determining protein interactions using a yeast two-hybrid system b. evaluating inbreeding depression in zoo populations c. identifying the likely source of DNA left at crime scenes d. calculating the risk of having an offspring with an inherited genetic disease

a. determining protein interactions using a yeast two-hybrid system

A fluorescently labeled primer that matches the _____ of a microsatellite can be used to determine the lengths of an individual's alleles. a. flanking sequences b. promoter sequence c. internal region d. repeated region

a. flanking sequences

Single nucleotide polymorphisms can have a maximum of _____ alleles at any one locus. a. four b. six c. two d. 20

a. four

A researcher is studying chipmunk populations inhabiting different parks in the same city. She notices that one chipmunk population appears to share many alleles with other populations from different parks. In other words, this particular chipmunk population demonstrates a rich genetic ancestry. This is an example of: a. genetic admixture. b. inbreeding depression. c. negative assortative mating. d. a discovery panel.

a. genetic admixture. - A genetic admixture is a mix of genes that results when individuals have ancestry from more than one subpopulation.

When N is large, F _____ over time. When N is small, F _____ over time. a. increases slowly; increases rapidly b. decreases slowly; decreases rapidly c. increases slowly; decreases rapidly d. decreases slowly; increases rapidly

a. increases slowly; increases rapidly

Besides single nucleotide polymorphisms and microsatellites, which of these do NOT provide genetic variation within a population? a. inductions b. duplications c. translocations d. deletions

a. inductions

White-throated sparrows have two major phenotypes: white-striped and tan-striped crown. Approximately 98 percent of the observed pairings (mated pairs or social pairs) between white-throated sparrows are between mates with different phenotypes and the correlation between mating types is −0.964. The white-throated sparrow exhibits _____ mating. a. negative assortative b. positive assortative c. inbred d. random

a. negative assortative

SNPs within protein-coding regions are _____ if the two alleles encode different amino acids. a. nonsynonymous b. nonsense c. silent d. synonymous

a. nonsynonymous

Which of these is NOT a type of bias in mate choice that violates the assumption of random mating? a. population structure b. isolation by distance c. inbreeding d. assortative mating

a. population structure

Directional selection can be either _____ or _____. a. positive; purifying b. positive; negative c. purifying; polluting d. polluting; negative

a. positive; purifying

The rich genetic variation in biological populations can be quantified by different statistics, including all of these EXCEPT _____, to compare levels of variation among populations and species. a. species type b. number of haplotypes c. number of segregating sites d. gene diversity

a. species type

The homozygous recessive yellow-head allele has a frequency of 0.25 in neotropical swallowtail butterflies. If the average inbreeding coefficient in the butterflies is 0.065, calculate the frequency of yellow-headed individuals in the next generation. a. 0.012 b. 0.075 c. 0.25 d. 0.0625

b. 0.075 - q2 + pqF = (0.25)2 + (0.75)(0.25)(0.065) = 0.0625 + 0.0121875 = 0.0746875.

A scientist is studying four haplotypes in mice: HR, Hr, hR, and hr. He determines these allele frequencies: pH= 0.7, ph = 0.3, pR = 0.4, and pr = 0.6. If the H and R loci are in linkage equilibrium, what will be the frequency of the Hr haplotype? a. 0.18 b. 0.42 c. 0.12 d. 0.28

b. 0.42

Which of these statements about single nucleotide polymorphisms is TRUE? a. All human SNPs were identified by comparing the genomes of two individuals, one from South America and one from Asia. b. A researcher who wanted to determine all of the SNPs in his or her genome could use a DNA microarray. c. All SNPs always demonstrate four alleles; unlike microsatellites, SNPs never have only two or three alleles. d. Only SNPs in coding regions of DNA can be used as genetic markers.

b. A researcher who wanted to determine all of the SNPs in his or her genome could use a DNA microarray.

_____ found in the mitochondrial (mtDNA) and chloroplast (cpDNA) genomes of eukaryotes. a. Both introns and exons are b. Both SNPs and microsatellites are c. Only introns are d. Only maternal DNA is

b. Both SNPs and microsatellites are

Which of these statements is TRUE? a. If a population demonstrates positive assortative mating, then this population is in Hardy-Weinberg equilibrium. b. Certain plant species exhibit disassortative mating to prevent self-fertilization and to bring genetic diversity to a population. c. As humans preferentially tend to mate with individuals carrying the same MHC haplotypes, humans are great examples of organisms that demonstrate only positive assortative mating. d. Disassortative mating is unique to prokaryotes and plants; no case of disassortative mating has ever been documented in mammals.

b. Certain plant species exhibit disassortative mating to prevent self-fertilization and to bring genetic diversity to a population.

A researcher has two mouse populations in his laboratory. He knows that r, the recombination frequency, in mouse population 1 is 0.2, and r in mouse population 2 is 0.5. What can he conclude about D in these two mouse populations? a. D will be declining in both populations but more slowly in population 2. b. D will be declining in both populations but more slowly in population 1. c. D will be increasing in population 2 but decreasing in population 1. d. D will be increasing in population 1 but decreasing in population 2.

b. D will be declining in both populations but more slowly in population 1. - The recombination frequency for the mouse population 2 is at its maximum, so D will decline more quickly in population 2.

Which formula can be used to calculate the inbreeding coefficients from this pedigree? a. FI = (1/2)3(1 + FA) b. FI = (1/2)5(1 + FA) c. FI = Σ(1/2)2(1 + FA) d. FI = (1/2)3(1 + FA1) + (1/2)3(1 + FA2)

b. FI = (1/2)5(1 + FA)

Which of these is the average inbreeding coefficient? a. FA b. Ft c. FI d. fA/a

b. Ft

You have been studying a newt population for three generations. You randomly sampled the breeding population in the first year of your study and have been randomly sampling the offspring in each generation since. For a specific locus, GY9, the first sampling gave allele frequencies of G = 0.67 and g = 0.33. The next two sampling periods had the same allele frequencies. What can you conclude about this newt population? a. It was in Hardy-Weinberg equilibrium only for the first two generations. b. It is in Hardy-Weinberg equilibrium. c. It is in Hardy-Weinberg equilibrium but was not for the first two generations. d. It is not in Hardy-Weinberg equilibrium.

b. It is in Hardy-Weinberg equilibrium.

If five microsatellite alleles in a blood sample from a crime scene and a suspect's DNA match, can a forensic scientist say without a doubt that the suspect left the evidence? a. Yes; if the suspect hadn't done it, he wouldn't be a suspect. b. No; it depends on how frequent the alleles are in the population. c. Yes; the alleles match. d. No; the researchers likely made a mistake during their blood sample collection; that is, either 15 microsatellite alleles will match or none of the microsatellite alleles will match.

b. No; it depends on how frequent the alleles are in the population.

Individuals often have different microsatellite alleles because microsatellites exhibit: a. a low mutation rate. b. a high mutation rate. c. a high rate of transcription. d. no mutations.

b. a high mutation rate.

All of these statements are true of population genetics EXCEPT for: a. Population geneticists usually do not care about the absolute counts of the different genotypes in a population. b. absolute counts are a more practical measurement than frequencies. c. Population geneticists draw a random or unbiased sample of individuals from a population. d. Frequencies sum to 1.0.

b. absolute counts are a more practical measurement than frequencies.

Linkage disequilibrium as measured by D declines at a rate of (1 − r) per generation. When r is small, D _____. When r is at its maximum (0.5), then D _____. a. declines quickly over time; increases by ½ each generation b. declines slowly over time; declines by ½ each generation c. increases slowly over time; increases quickly over time d. increases by ½ each generation; declines slowly over time

b. declines slowly over time; declines by ½ each generation

Calculating the risk of having an offspring with an inherited genetic disease incorporates information on: a. genotypes of unaffected individuals in a pedigree. b. desegregation of alleles. c. genotypes of affected individuals in a pedigree. d. allele frequencies in a population.

b. desegregation of alleles.

This equation informs us that F will _____ over time as a function of _____. Ft + 1 = (1/(2N))1 + (1 − 1/(2N))Ft. a. decrease; population size b. increase; population size c. decrease; level of inbreeding d. increase; level of inbreeding

b. increase; population size

Microsatellites often have _____ at each locus. a. only 10 alleles b. more than 20 alleles c. only a single allele d. only two alleles

b. more than 20 alleles

A researcher is studying the same locus in two individuals. This locus is composed of six nucleotides: the sequence in individual 1 is ATGCAT, and the sequence in individual 2 is ATGGAT. At position four in this sequence, a C base has been replaced by a G base. This is a: a. microarray. b. single nucleotide polymorphism. c. microsatellite. d. macrosatellite.

b. single nucleotide polymorphism.

SNPs within protein-coding regions are _____ if the different alleles encode the same amino acid. a. nonsense b. synonymous c. nonsynonymous d. silent

b. synonymous

Using the equation for balanced mutation and drift, what is the equilibrium value of heterozygosity for a population of 10,000 with a mutation rate of 4 × 10−8? a. 16.0 b. 0.0160 c. 0.00160 d. 1.60

c. 0.00160 (4Nμ)/(4Nμ+ 1) = (4(10,000)(4 × 10−8))/(4(10,000)(4 × 10−8)+1)

A scientist is studying four haplotypes in chickens_____: ST, St, sT, and st. He determines these allele frequencies: pS = 0.3, ps = 0.7, pT = 0.8, and pt = 0.2. If the S and T loci are in linkage equilibrium, what will be the frequency of the st haplotype? a. 0.24 b. 0.56 c. 0.14 d. 0.06

c. 0.14 - ps × pt = 0.7 × 0.2 = 0.14.

In a large population, the average inbreeding coefficient will increase very slowly over time. However, in a small population, the inbreeding coefficient can increase rapidly. In a population of 10 having an average inbreeding coefficient of 0.1, calculate the average inbreeding coefficient of the next generation. a. 0.1 b. 0.5 c. 0.145 d. 0.95

c. 0.145 Ft + 1 = (1/(2N))1 + (1 − (1/2N))Ft = 1/20 + (1 − 1/20) 0.1 = 0.5 + (0.95) 0.1 = 0.5 + 0.095 = 0.145

A researcher is studying a population of organisms in which inbreeding occurs frequently. He knows that for two alleles, C and c, p and q are 0.75 and 0.25. If F in this population is 0.25, what will be the frequency of CChomozygotes in this population? a. 0.28 b. 0.16 c. 0.66 d. 0.47

c. 0.66

If q is equal to 0.28, what is p equal to? a. 1.44 b. 0.36 c. 0.72 d. 0.28

c. 0.72

In a sample of 10 frogs there are 15 A alleles and 5 a alleles. Assume the population is in Hardy-Weinberg equilibrium. What are the genotype frequencies in this sample? a. A/A = 0.60, A/a = 0.40, a/a = 0.00 b. A/A = 0.375, A/a = 0.56, a/a = 0.0625 c. A/A = 0.563, A/a = 0.375, a/a = 0.0625 d. A/A = 0.33, A/a = 0.33, a/a = 0.33

c. A/A = 0.563, A/a = 0.375, a/a = 0.0625

Migration can cause LD when one subpopulation possesses only the _____ haplotype and another only the _____ haplotype. a. Ab; aB b. aB; ab c. AB; ab d. AB; Ab

c. AB; ab

Which of these statements about microsatellites is TRUE? a. If you were to compare the microsatellites in several generations of the same family, you would find that all individuals have the same alleles. This is because microsatellites have low mutation rates. b. Microsatellites are primarily found in coding regions of DNA (exons); microsatellites rarely occur in noncoding DNA and introns. c. Discovering microsatellite loci in the genome of a species is done by performing a computer search of its complete genomic sequence. d. Microsatellites typically consist of repeating stretches of 10 base-pair sequences; microsatellites composed of shorter repeating sequences are very rare and not normally found in the genome.

c. Discovering microsatellite loci in the genome of a species is done by performing a computer search of its complete genomic sequence.

Which of these statements is true of the G6PD gene in humans? a. The complete G6PD locus is always considered a fixed site in a population from Africa. b. In any two populations of humans, the S and NH values for the G6PD locus are equal. c. The B allele of the G6PD gene demonstrates the highest frequency in humans. d. Only two alleles exist for the G6PD gene―the wild-type B allele and the mutant A− allele.

c. The B allele of the G6PD gene demonstrates the highest frequency in humans.

Which of these statements is TRUE? a. The frequencies of the different heterozygous classes are half the product of the frequencies of the first and second allele. b. If allele a has a frequency of 1 in a thousand, then only 1 in a thousand individuals will be homozygous for that allele. c. The Hardy-Weinberg law still applies where there are more than two alleles per locus. d. The frequencies of each of the homozygous genotypes are simply the square root of the frequencies of the alleles.

c. The Hardy-Weinberg law still applies where there are more than two alleles per locus.

A researcher is studying a new gene in humans. In her sample population, she determines that the GD value for her locus of interest is 0. What can she conclude? a. The gene she is studying plays no role in determining any human phenotype. b. The gene she is studying must be G6PD. c. The gene she is studying has only one allele in her sample population. d. The gene she is studying has two alleles in her sample population.

c. The gene she is studying has only one allele in her sample population. - Gene diversity (GD) is the probability that two alleles drawn at random from the gene pool will be different. It is 0 when there is a single allele, and it is near 0 whenever there is a single very common allele with a frequency of 0.99 or higher.

_____ is the probability that two alleles in an individual are descended from a common ancestor. a. Population structure b. Disassortativeness c. The inbreeding coefficient d. Inbreeding depression

c. The inbreeding coefficient

A researcher is studying two sets of linked loci in mice. Both sets consist of one mutant allele and one wild-type allele. For the first set of linked loci, the D value is 0.4. For the second set, the D value is 0.1. What can the researcher conclude? a. The mutant alleles in both sets of linked loci originated at the same time. b. Neither set of linked loci demonstrates linkage disequilibrium. c. The mutant allele in the second set of linked loci originated earlier than the mutant allele in the first set of linked loci. d. The mutant allele in the first set of linked loci originated earlier than the mutant allele in the second set of linked loci.

c. The mutant allele in the second set of linked loci originated earlier than the mutant allele in the first set of linked loci. - Older mutations have little LD with neighboring loci, while recent mutations show a high level of LD with neighboring loci. A larger value for D indicates greater LD.

Which of these is NOT an advantage of self-pollination? a. If an individual plant has a beneficial combination of alleles at different loci, inbreeding preserves that combination. b. When a single seed is dispersed to a new location, the plant that grows from the seed has a ready mate—itself. c. The stigma of an S1/S2 heterozygote will not allow pollen grains carrying either an S1 or S2 allele to germinate and fertilize its ovules. d. Self-pollination can be accomplished more easily than outcrossing.

c. The stigma of an S1/S2 heterozygote will not allow pollen grains carrying either an S1 or S2 allele to germinate and fertilize its ovules.

The assumption of random mating has been violated if any of these is a more likely mate than a random individual, EXCEPT for: a. a phenotypically similar individual. b. a relative. c. a stranger. d. a neighbor.

c. a stranger.

The South African Afrikaner population is descended mainly from a few colonists. Today, the Afrikaner population has an unusually high frequency of the gene that causes Huntington disease, because the gene was represented with unusually high frequency in the original Dutch colonists. This is an example of a population _____. a. discovery panel b. gene pool c. bottleneck d. genetic admixture

c. bottleneck

Single nucleotide polymorphisms are considered _____ if they occur at a frequency of at least 0.05 in the population. a. HapMaps b. mutations c. common d. rare

c. common

A scientist is studying nucleotide diversity in many model organisms. Which organism do you suspect will demonstrate the LEAST nucleotide diversity? a. flies b. bacteria c. mice d. yeast

c. mice

Hunting reduced the northern elephant seal population size to as few as 20 individuals by the end of the nineteenth century. Since then, their population has increased to over 30,000, but they have much less genetic variation than a population of southern elephant seals that was not so intensely hunted. This is an example of a: a. discovery panel. b. genetic admixture. c. population bottleneck. d. gene pool.

c. population bottleneck.

A researcher is studying a single duck gene with two alleles, B and b. She samples ducks from five populations, each of which appears isolated and tends to stay near a unique body of water. Using the Hardy-Weinberg law, the researcher predicts that she will observe 100 ducks with the b/b genotype out of all of the ducks she samples. However, she is surprised to find that 220 ducks demonstrate the b/bgenotype. This is likely due to _____ in the duck species. a. positive assortative b. disassortative mating c. population structure d. negative assortative mating

c. population structure

Most people in the United States want to marry someone whose educational background and income level is similar to their own. The extent to which this has become an issue in determining who to marry has become greater since the rise of women in the workforce. This is an example of _____ mating. a. random b. inbred c. positive assortative d. negative assortative

c. positive assortative

Which of these types of mating can cause a population NOT to be in Hardy-Weinberg equilibrium? a. negative assortative mating b. positive assortative mating c. random mating d. disassortative mating

c. random mating?

A researcher has identified a new single nucleotide polymorphism in an intron of a rabbit gene. Despite the presence of this SNP, the rabbit appears to be phenotypically normal. The researcher has likely isolated a new _____ SNP. a. synonymous b. nonsense c. silent d. nonsynonymous

c. silent - Silent SNPs are a type of noncoding SNP (those found in introns) that has no effect on gene function and phenotype.

You have a blood sample from a crime scene. The microsatellite alleles are A4/A6 at the A locus and B8/B15 at the B locus. The allele frequencies of the alleles in the population are as follows: A4 = 0.3 A6 = 0.5 B8 = 0.45 B15 = 0.25 What is the probability of having this genotype in the general population? a. 0.0338 b. 0.0169 c. 0.675 d. 0.0675

d. 0.0675 - The probability of this genotype is (2 × A4 × A6) × (2 × B8×B15)

A scientist is studying four haplotypes in mice: HR, Hr, hR, and hr. He determines these allele frequencies: pH= 0.7, ph = 0.3, pR = 0.4, and pr = 0.6. If the H and R loci are in linkage equilibrium, what will be the frequency of the Hr haplotype? a. 0.18 b. 0.12 c. 0.28 d. 0.42

d. 0.42 - pH × pr = 0.7 × 0.6 = 0.42

If p is equal to 0.56, what is q equal to? a. 0.88 b. 0.22 c. 0.56 d. 0.44

d. 0.44

A sheep farmer is worried about mutations in his flock. If his flock consists of 2000 sheep, what is the probability that any novel mutation appearing in his sheep flock will eventually be lost? a. 0.77775 b. 0.56554 c. 0.00025 d. 0.99975

d. 0.99975 - 1 − 1/(2N) = 1 - 1/4000 = 0.99975.

Inbreeding violates the random mating assumption of the Hardy-Weinberg law. Which of these represents the inbreeding modification for heterozygotes using the Hardy-Weinberg law? a. q2 + 2pqF b. p2 + 2pqF c. p2 − 2pqF d. 2pq − 2pqF

d. 2pq − 2pqF

_____ is the probability that two alleles drawn at random from the gene pool will be different. a. Haplotype (NH) b. Segregating (S) c. Nucleotide diversity d. Gene diversity (GD)

d. Gene diversity (GD)

The star-cluster haplotype for the Y chromosome, which has a high frequency in Mongolia, dates to about 1000 years ago. The distribution of this haplotype correlates with the boundaries of the empire established by _____. It is believed that this haplotype traces to his lineage. a. Julius Caesar b. Alexander the Great c. Louis XIV d. Genghis Khan

d. Genghis Khan

Populations that _____ random mating _____ exhibit exact Hardy-Weinberg proportions for the genotypes at some or all genes. a. are; will not b. are not; will c. are not; will sometimes d. are not; will not

d. are not; will not

The first farmers placed domesticated populations through a _____. As a consequence, crop plants and domesticated animals typically have _____ genetic variation than their wild progenitors. a. bottleneck; more b. genetic admixture; more c. genetic admixture; less d. bottleneck; less

d. bottleneck; less - A period of one or several consecutive generations of contraction in population size is known as a population bottleneck. The reduction in population size results in less genetic variation.

Imagine you are a scientist studying an X-linked trait determined by two alleles of the same gene, H and h, in a human population. You have determined that in women, fH/H = 0.16 and fh/h = 0.36. Using this information, what can you conclude about frequency of the Y/H genotype in men? a. fY/H = 0.6 b. fY/H = 0.16 c. fY/H = 0.36 d. fY/H = 0.4

d. fY/H = 0.4 - fY/H = p2, so p = 0.4

A researcher is studying a single nucleotide polymorphism in a population of turtles. He notices that at the locus of interest, all of the turtles sampled possess an A nucleotide. In this turtle population, this site would be: a. modified or fixed. b. variable or fixed. c. invariant or modified. d. fixed or invariant.

d. fixed or invariant.

A horse breeder is presented with five stallions, and she chooses the stallion she thinks demonstrates the greatest Darwinian fitness. Likely the stallion she chose: a. appears strong. b. sired many foals. c. is healthy with no history of disease. d. has sired many foals, is strong and healthy, and has no history of disease.

d. has sired many foals, is strong and healthy, and has no history of disease.

Evolutionary biologists theorize that the cheetah population experienced a genetic bottleneck, which involved a reduction in the gene pool. As a result, cheetahs have very little genetic variation, leading to an increased expression of deleterious recessive alleles. This in turn leads to a decrease in the fitness in the entire population, a phenomenon known as _____. a. genotypic frequency b. genetic rescue c. selfing d. inbreeding depression

d. inbreeding depression

Conservation biologists are concerned about physical abnormalities in inbred populations of Florida panthers. To infuse the population with new genetic variation, biologists moved several panthers from a Texas population into Florida. The offspring of the Florida panthers and the new panthers showed an increase in genetic diversity because of: a. drift. b. selection. c. mutation. d. migration.

d. migration.

There were 261 matings documented in the wolves of Yellowstone National Park between 1995 and 2015. Of these, 63.6 percent were between gray and black wolves, and the correlation between mates for color was −0.266. What type of mating is taking place here? a. inbred b. random c. positive assortative d. negative assortative

d. negative assortative

The process of _____ is the foundation for the _____, the constant rate of substitution of newly arising allelic variants for preexisting ones over long periods. a. positive evolution; gene flow b. negative evolution; molecular clock c. positive evolution; gene flow d. neutral evolution; molecular clock

d. neutral evolution; molecular clock - The process of neutral evolution is the foundation for the molecular clock, the constant rate of substitution of newly arising allelic variants for preexisting ones over long periods.

All of these are single nucleotide polymorphisms found in exons, EXCEPT: a. synonymous. b. nonsynonymous. c. nonsense. d. noncoding.

d. noncoding. - Noncoding SNPs (ncSNPs) are found in introns, not exons.

A researcher has identified two new single nucleotide polymorphisms in mice. The first SNP occurs in noncoding DNA, and as such is a _____ SNP. The second occurs in an exon; it changes an amino acid produced by the affected mouse gene but does not produce a stop codon. The researcher would classify this as a _____ SNP. a. nonsynonymous; noncoding b. noncoding; synonymous c. nonsynonymous; synonymous d. noncoding; nonsynonymous

d. noncoding; nonsynonymous

A researcher is studying a single duck gene with two alleles, B and b. She samples ducks from five populations, each of which appears isolated and tends to stay near a unique body of water. Using the Hardy-Weinberg law, the researcher predicts that she will observe 100 ducks with the b/b genotype out of all of the ducks she samples. However, she is surprised to find that 220 ducks demonstrate the b/bgenotype. This is likely due to _____ in the duck species. a. positive assortative b. negative assortative mating c. disassortative mating d. population structure

d. population structure

A scientist is evaluating the same region in two homologous chromosomes in mice. She knows that the Dand T gene loci are in this chromosome region and that the mice have D, D, T, and t alleles, that are homozygous dominant for D and heterozygous for T. How many haplotypes are possible in these mice? a. four b. eight c. six d. two

d. two