Biology Exam 3

Which of the following chromosome number abnormalities have detectable phenotypic effects? 47, XXY 47, XYY 47, +21 47, XXX 45, X

47, XXY 47, +21 45, X

Cultural traits are transmitted horizontally and vertically through learning. Which of the examples below shows the horizontal transmission of culture?

A teenager teaches her brother how to text.

To be useful for phylogenetic reconstruction, a taxonomic character must exhibit which of the following properties? A) It must have a genetic basis. B) It must be anatomical. C) None of the other answer options is correct. D) It must be molecular (DNA or protein). E) It must vary among the taxa being analyzed, but not within individual taxa.

A) It must have a genetic basis. E) It must vary among the taxa being analyzed, but not within individual taxa.

Nondisjunction in _____ results in offspring inheriting the mutation. A) Meiosis B) Mitosis

A) Meiosis

The presence of an extra X chromosome is more likely to result in a viable human fetus than an extra copy of an autosome because: A) None of the answer options is correct. B) the X and the Y chromosomes do not recombine along most of their length. C) the X chromosome carries few genes, so dosage is not a problem. D) the X chromosome is the "female" chromosome. E) expression of genes from the X chromosome is restricted to early development of females.

A) None of the answer options is correct.

Which of the following BEST describes the behavior of the human X and Y chromosomes during meiosis? (Select all that apply.) A) The X and Y chromosomes have regions of homology that allow them to pair during meiosis. B) The X and Y chromosomes have no regions of homology and therefore do not pair during meiosis. C) Crossover occurs when the X and Y chromosomes pair during meiosis. D) None of the other answer options is correct. E) Although the X and Y chromosomes pair during meiosis, crossover does not occur.

A) The X and Y chromosomes have regions of homology that allow them to pair during meiosis. C) Crossover occurs when the X and Y chromosomes pair during meiosis.

Which statement BEST explains why embryos with a missing autosome are not always factored into statistics about spontaneously aborted fetuses? A) The fetus is aborted before the pregnancy is recognized. B) None of the other answer options is correct. C) Fertilization does not occur under these circumstances. D) These embryos do not get aborted but continue to live birth. E) These embryos occur less often than those with an extra autosome.

A) The fetus is aborted before the pregnancy is recognized

Only homologous characters are useful in constructing phylogenetic trees. A) True B) False

A) True

Phylogenetic trees can be used to infer character states of extinct organisms. A) True B) False

A) True

Polar bears arose from a vicariant event. A) True B) False

A) True

In regions where malaria is prevalent, the S allele is beneficial because: A) it causes red blood cells to distort, which makes them less hospitable to Plasmodium, the parasite that causes malaria. B) it improves the ability of the hemoglobin to carry oxygen. C) it improves the ability of the immune system to fight Plasmodium, the parasite that causes malaria. D) it prevents mosquitoes from releasing Plasmodium, the mosquito that causes malaria, into the blood. E) None of the answer options is correct.

A) it causes red blood cells to distort, which makes them less hospitable to Plasmodium, the parasite that causes malaria.

A cross involving an autosomal gene versus a sex-linked gene would differ in that: A) the phenotype outcomes of females compared to males could be different. B) both parents would have two copies of a sex-linked gene. C) a Punnett square could not be utilized for solving a cross involving a sex-linked gene. D) only autosomal genes observe the law of segregation. E) recombination or crossing over could not take place between sex chromosomes.

A) the phenotype outcomes of females compared to males could be different.

Using PCR to amplify the same region of the genome from different individuals can identify differing lengths due to different numbers of repeated sequences referred to as: A) variable number tandem repeats. B) single-nucleotide polymorphisms. C) copy-number variations. D) first-division non-disjunctions. E) restriction fragment length polymorphisms.

A) variable number tandem repeats.

In a fish species the eggs tend to be fertilized more often by the mid-sized males and less often by the largest and smallest males. This is an example of: A. stabilizing selection. B. directional selection. C. disruptive selection. D. None of the other answer options is correct.

A. stabilizing selection.

What is true regarding adaptive radiation?

Adaptive radiation is more likely to occur in a population produced by a dispersal event than in a long-established population on a continent.

What is the primary difference between natural selection and artificial selection?

Artificial selection is driven by humans

If 8 alleles exist in a population, what is the maximum number of copies a normal individual is expected to have? A) 8 B) 2 C) 5 D) 4 E) 3

B) 2

Recall that in Mendel's garden peas, the yellow gene determines flower color, with the A (yellow) allele dominant to the a (green) allele. In a population of 200 plants, the genotype frequencies are 50% AA, 25% Aa, and 25% aa. What are the allele frequencies? A) 50% A, 25% a B) 62.5% A, 37.5% a C) 50% A, 50% a D) 75% A, 25% a E) 87.5% A, 12.5% a

B) 62.5% A, 37.5% a

Ultraviolet light is a mutagen, but humans need some exposure to it in order to synthesize vitamin D3. The amount of ultraviolet light that penetrates the skin depends on the skin's pigmentation: more melanin (skin pigment) means less penetration. Certain mutations result in decreased melanin production. Such mutations: A) Are neutral only if inherited from one parent, not the other. B) May be harmful in one environment and beneficial in another. C) Are beneficial only if inherited from both parents. D) Are harmful only if inherited from both parents.

B) May be harmful in one environment and beneficial in another.

Are all point mutations SNPs? A) Yes, because SNPs are single base-pair changes of the DNA. B) No, because SNPs require a certain frequency in the population. C) Yes, because SNPs are random in their occurrence. D) No, because SNPs are mismatched base pairs.

B) No, because SNPs require a certain frequency in the population.

Which of the following statements BEST describes the effect of having the S allele, which codes for sickle-cell anemia? A)The effect depends on the environment (i.e., whether malaria is present). B)The effect depends on whether the allele occurs in its homozygous or heterozygous form, and the environment (i.e., whether malaria is present). C) Having the allele is always harmful. D) The effect depends on whether the allele occurs in its homozygous or heterozygous form. E) Having the allele is always beneficial.

B) The effect depends on whether the allele occurs in its homozygous or heterozygous form, and the environment (i.e., whether malaria is present).

Two individuals with the same genotype may not express the same phenotype because gene expression is influenced by: A) other genes alone. B) a combination of genes and environment. C) None of the answer options is correct D) the environment alone. E) genes alone in some people and the environment alone in other people.

B) a combination of genes and environment.

The lethality of most monosomies and trisomies in humans shows the: A) advantage of sexual reproduction. B) importance of gene dosage. C) deleterious effects of variable number tandem repeat sequences. D) rarity of gene copy-number variation in the genome.

B) importance of gene dosage.

Mitochondrial DNA is useful for tracing ancestry because: A) both recombination and mutation in mitochondrial DNA are rare. B) recombination rarely occurs. C) mutations in mitochondrial DNA are almost always harmful. D) both recombination and mutation in mitochondrial DNA are rare, but when mutations do occur, they are almost always harmful. E) mutations in mitochondrial DNA are rare; mitochondrial DNA has relatively little variation.

B) recombination rarely occurs.

When DNA with variable number tandem repeats (VNTRs) is visualized on a gel, the resulting fragments separate according to their: A) A-T content. B) size. C) shape. D) color. E) G-C content.

B) size.

In Mendel's garden peas, each cell in a pea plant has a total of: A) between one and four alleles for each gene. B) two alleles for each gene. C) one allele for each gene, if it has green seeds and two if it has yellow seeds. D) one allele for each gene. E) one allele for each gene, if it is a true-breeding parent and two if it is an F1 offspring.

B) two alleles for each gene.

A mutation in the BRCA1 gene is associated with which disease? (Select all that apply.) A)colon cancer B)ovarian cancer C) bone cancer D) retinal cancer E) breast cancer

B)ovarian cancer E) breast cancer

A cattle breeder selects the largest males for breeding with the largest females. This is an example of: A. stabilizing selection. B. directional selection. C. disruptive selection. D. None of the other answer options is correct.

B. directional selection.

Why do we think that male Neanderthals mated with non-African ancestral Homo sapiens?

Because Neanderthal nuclear DNA sequences are present in the human gene pool, and Neanderthal mtDNA sequences are not.

Linked genes have recombination frequencies between: A) 0 and 100%. B) 0 and 25%. C) 0 and 50%. D) 0 and 10%. E) 0 and 75%.

C) 0 and 50%.

Diploid somatic cells of elephants have 56 chromosomes. If nondisjunction of one of an elephant's chromosomes occurs in meiosis II, the resulting sperm are expected to have the chromosome complement: A) 28, 28, 28, 28. B) 29, 29, 28, 28. C) 28, 28, 29, 27 D) 29, 29, 27, 27. E) 56, 56, 57, 55.

C) 28, 28, 29, 27

Which one of the following statements about restriction fragment length polymorphisms (RFLPs) is CORRECT? A) RFLPs can take the place of VNTRs in forensic analyses. B) RFLPs are the product of cleavage by restriction enzymes. C) All of these choices are correct. D) RFLPs are variations in restriction sites that result in DNA being cleaved into different-sized pieces. E) RFLPs are numerous in the human population.

C) All of these choices are correct.

To discover the location of a genetic mutation that causes disease in humans, scientists use genetic mapping. Specifically, they look for genetic markers, or previously discovered DNA polymorphisms, that show statistical association with the disease gene. The statistical association means that the: A) DNA polymorphism causes the disease. B) Disease causes the DNA polymorphism. C) DNA polymorphism and the disease gene are linked. D) DNA polymorphism and the disease gene are unlinked.

C) DNA polymorphism and the disease gene are linked.

Which of the following statements about single-nucleotide polymorphisms (SNPs) is CORRECT? (Select all that apply.) A) An individual is unlikely to be heterozygous for one or more SNPs. B) The presence of an SNP in an organism's genome when compared to the "standard" genome of that organism means that a disease condition will develop. C) Genotyping SNPs instead of sequencing entire genomes allows researchers to find correlations between genetic risk factors and disease. D) SNPs are useful in the diagnosis of a disease but not in the prediction of an individual's risk for acquiring that disease. E) For some disorders, multiple SNPs plus environmental factors are necessary in order for the disorder to present itself.

C) Genotyping SNPs instead of sequencing entire genomes allows researchers to find correlations between genetic risk factors and disease. D) SNPs are useful in the diagnosis of a disease but not in the prediction of an individual's risk for acquiring that disease. E) For some disorders, multiple SNPs plus environmental factors are necessary in order for the disorder to present itself.

Genetic studies have identified an allele (Δ32) that seems to provide protection against HIV. Which of the following would MOST likely explain the reason why our population has this mutation? A) Our bodies are designed to protect us against a myriad of pathogens, and the immune system was preparing for future viruses similar to HIV. B) This mutation was likely induced in the genome by the presence of the HIV virus. C) This mutation likely benefited the human population against some other related pathogen. D) This mutation is very likely a neutral mutation.

C) This mutation likely benefited the human population against some other related pathogen.

The nonmutant allele of the BRCA1 gene helps to suppress tumor formation in women who are heterozygous for the mutation. Women homozygous for BRCA1 nevertheless have a 50% to 70% chance of developing breast cancer before age 70, and the usual reason is that the nonmutant allele is lost or inactivated in a lineage of cells. One possible mechanism for such "loss of heterozygosity" is: A) a silent mutation occurs in the nonmutant BRCA1 allele. B) germ cells in the affected individual develop a mutation in the nonmutant allele of BRCA1 C) a somatic mutation in a breast cell inactivates the nonmutant BRCA1 allele.

C) a somatic mutation in a breast cell inactivates the nonmutant BRCA1 allele.

Human triploid and tetraploid fetuses occur, but they are inviable and undergo spontaneous abortion. Any of the following events could produce a polyploid fetus EXCEPT: A) failure of homologous chromosomes to separate. B) chromosome duplication without cell division. C) development of an unfertilized ovum. D) fertilization of an egg by more than one sperm. E) defective spindle apparatus during early mitosis.

C) development of an unfertilized ovum.

When Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants, the offspring were genotypically: A) a mixture of yellow and green seeds. B) yellow seeds. C) made up of a combination of yellow and green alleles. D) green seeds.

C) made up of a combination of yellow and green alleles.

The rate differences between molecular clocks are due largely to differences in _____. Thus, the extreme case of a fast molecular clock is derived from a _____. A) the intensity of selection; histone proteins. B) the size of the molecule; pseudogenes. C) the intensity of selection; pseudogene. D) the size of the molecule; histone proteins. E) None of the answer options is correct.

C) the intensity of selection; pseudogene.

Imagine a region of DNA containing a variable number tandem repeat (VNTR) that is found in the genome of koalas. The possible number of VNTR alleles in the population equals the number of: A) genes. B) restriction fragment length polymorphisms there are in the genome. C) times a short noncoding sequence is repeated in tandem along the DNA. D) base pairs. E) times a gene is repeated in tandem along the DNA.

C) times a short noncoding sequence is repeated in tandem along the DNA.

Genetic drift is more likely to cause evolution in a small population than in a large one because: A.mutation rates are higher in small populations. B. random events occur more often in small populations. C. with fewer individuals, which individuals mate can have larger effects in small populations. D.All of these choices are correct.

C. with fewer individuals, which individuals mate can have larger effects in small populations.

What is true regarding chloroplast inheritance?

Chloroplasts can demonstrate maternal, parental, or biparental patterns of inheritance depending on the plant species

What is the approximate percentage of the genome that is subject to copy-number variation (CNV)? A) 100% B)50% C) 1% D) 10% E) 80%

D) 10%

Diploid somatic cells of elephants have 56 chromosomes. If nondisjunction of one of an elephant's chromosomes occurs in meiosis I, the resulting sperm are expected to have the chromosome complement: A) 29, 29, 28, 28. B) 56, 56, 57, 55. C) 28, 28, 29, 27 D) 29, 29, 27, 27. E) 28, 28, 28, 28.

D) 29, 29, 27, 27.

Which of the following is true of BOTH first- and second-division nondisjunction? (Select all that apply.) A) Homologous chromosomes fail to separate. B) Sister chromatids fail to separate. C) Half of the gametes produced are wild-type, whereas half are mutated. D) Gametes are produced with extra chromosomes. E) Gametes are produced with missing chromosomes.

D) Gametes are produced with extra chromosomes. E) Gametes are produced with missing chromosomes.

Which statement about the PiZ allele is NOT true? A) The PiZ allele is common in populations of European descent. B) Smokers who are homozygous for the PiZ allele have a shortened life expectancy. C) Normal lung elasticity depends on elastase inhibition. D) Individuals homozygous for the PiZ allele have normal lung elasticity. E) The product of non-mutant alleles of the gene inhibits elastase in the lungs.

D) Individuals homozygous for the PiZ allele have normal lung elasticity.

For the majority of SNPs implicated in disease, how does carrying a copy affect a person's risk for acquiring that disease? A) It decreases it minimally. B) It increases it dramatically. C) It decreases it dramatically. D) It increases it moderately. E) It decreases it moderately.

D) It increases it moderately.

Which of the following statements is TRUE about Klinefelter syndrome (47, XXY)? A) None of the other answer options is correct. B) Most affected fetuses undergo spontaneous abortion. C) The risk increases with the father's age. D) Nondisjunction is the usual cause. E) Affected males can reproduce normally.

D) Nondisjunction is the usual cause.

Consider Mendel's experiments involving the trait of round versus wrinkled peas. In some experiments, Mendel removed the anthers of the flowers from a plant that was true-breeding for round peas and applied pollen from the anthers of a plant that was true-breeding for wrinkled peas. What would have happened if Mendel missed some anthers that he was trying to remove from the true-breeding round pea plants, and then counted the peas produced by a plant that bore a mix of round and wrinkled pollen? Indicate which of the following must be TRUE: A) The F1 peas would have phenotypes in a 1:1 ratio. B) The F1 peas produced would have mixed phenotypes. C) The F2 peas would all have the phenotype of the parental plant with the anthers not properly removed. D) The F1 peas produced would have a single phenotype. E) The F2 peas would have phenotypes in a 9:3:3:1 ratio.

D) The F1 peas produced would have a single phenotype.

The difference between a single-nucleotide polymorphism (SNP) and a point mutation is that: A) a point mutation can be corrected by various repair mechanisms, whereas an SNP cannot. B) an SNP can be corrected by various repair mechanisms, whereas a point mutation cannot. C) an SNP becomes permanently incorporated into the genome, whereas a point mutation does not. D) a point mutation is when a base pair is changed to a different base pair, whereas an SNP is when the base pair differs among individuals in a population. E) a point mutation becomes permanently incorporated into the genome, whereas an SNP does not.

D) a point mutation is when a base pair is changed to a different base pair, whereas an SNP is when the base pair differs among individuals in a population.

A trait with variable expressivity is one that: A) is only expressed in homozygous recessive individuals. B) is expressed in only some offspring of affected individuals. C) is only expressed in homozygous dominant individuals. D) can be expressed differently in different individuals that have the genotype for that trait. E) is only expressed in some of the individuals that have the genotype for that trait.

D) can be expressed differently in different individuals that have the genotype for that trait.

The phenotype of an individual results from an interaction between: A) genotype and mutation rate. B) allele frequency and genotype. C) allele frequency and the environment. D) genotype and the environment. E) allele frequency and mutation rate.

D) genotype and the environment.

In some large groups of plants, including dandelions, oaks, and willows, the biological species concept is complicated because the process of _____ allows gene flow to occur between good _____ that can be easily distinguished based on appearance. A) hybridization; ecological species B) allopatric speciation; ring species C) polyploidy; ring species D) hybridization; morphospecies E) polyploidy; evolutionary species

D) hybridization; morphospecies

In genetic mapping, a map unit is defined as: A) the distance between genes resulting in 50% recombination. B) the physical distance between the two genes. C) 1 millimeter. D) the distance between genes resulting in 1% recombination. E) 1 micrometer.

D) the distance between genes resulting in 1% recombination.

In humans, one reason why mitochondrial inheritance is strikingly different from nuclear inheritance is that: A) mitochondrial DNA is single-stranded. B) mitochondrial DNA is circular. C) mitochondrial inheritance is sex-linked. D) unlike nuclear inheritance, both parents do not contribute mitochondrial DNA. E) unlike mitochondrial inheritance, only one parent contributes nuclear DNA.

D) unlike nuclear inheritance, both parents do not contribute mitochondrial DNA.

Which of the following is not a contributor to genetic drift? A. founder event B. bottleneck C. random change in allele frequency D. natural selection E. population size

D. natural selection

The risk of having a baby with Down syndrome is associated with which one of the following? A) IQ of the mother B) All of these choices are correct. C) Socio-economic status of the mother D) Health of the mother E) Age of the mother

E) Age of the mother

Which of the following is true regarding hybridization? A) Hybridization occurs in plants more often than in animals. B) Hybridization involves the transfer of genetic material between members of similar species. C) Natural selection sometimes acts against progeny that result from hybridization. D) Hybridization can result in fertile offspring. E) All of these choices are correct.

E) All of these choices are correct.

Mendel's experiments with garden peas differed from those of other plant hybridizers of the time in that: A) Mendel focused on a small number of easily contrasted traits instead of a large number of more complex traits. B) Mendel quantified his results and looked for statistical patterns instead of simply noting the presence or absence of a trait among a group of offspring. C) Mendel studied true-breeding strains instead of poorly defined material. D) Mendel performed no crosses between strains, whereas other hybridizers did. E) Mendel studied true-breeding strains, focused on a small number of easily contrasted traits, and quantified results.

E) Mendel studied true-breeding strains, focused on a small number of easily contrasted traits, and quantified results.

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. A) XXO; nondisjunction B) XXO; independent assortment C) XXY; random segregation D) XXX; nondisjunction E) XXY; nondisjunction

E) XXY; nondisjunction

In general, sympatric speciation requires the action of _____ selection acting against hybrids. A) stabilizing B) artificial C) directional D) ecological E) disruptive

E) disruptive

According to the principle of segregation, a heterozygous plant with alleles Aa will produce: A) gametes with only the a allele. B) gametes in the ratio of 3 A alleles:1 a allele. C) some gametes with the A allele and some with the a allele, but in no predictable ratio. D) gametes with only the A allele. E) gametes in the ratio of 1 A allele:1 a allele.

E) gametes in the ratio of 1 A allele:1 a allele.

A trait with incomplete penetrance is one that: A) is only expressed in homozygous recessive individuals. B) is only expressed in homozygous dominant individuals. C) can be expressed differently in different individuals that have the genotype for that trait. D) is expressed in only some offspring of affected individuals. E) is only expressed in some of the individuals that have the genotype for that trait.

E) is only expressed in some of the individuals that have the genotype for that trait.

The correlation between the time two species have been evolutionarily separated and the amount of genetic divergence between them is known as the: A) artificial selection. B) Modern Synthesis. C) natural selection. D) Hardy-Weinberg equilibrium. E) molecular clock.

E) molecular clock.

Biochemical recognition systems within the stigma of a flowering plant prevent the pollen from a different species from developing a pollen tube and fertilizing its eggs. This is an example of what kind of reproductive isolation? A) post-zygotic, temporal separation B) pre-zygotic, temporal separation C) post-zygotic, ecological separation D) pre-zygotic, behavioral isolation E) pre-zygotic, lock and key

E) pre-zygotic, lock and key

You are examining a human pedigree for a trait. You notice that an offspring can be affected even if neither parent is affected. This immediately tells you that the trait is: A) produced by multiple alleles. B) incomplete penetrance. C) epistatic. D) dominant. E) recessive.

E) recessive.

What is a possible explanation for why a population may not be in Hardy-Weinberg equilibrium?

Evolution is occurring on a trait in the population

In pedigrees,

Females are circles and males are squares

The burning of fossil fuels for energy in the modern era of life on Earth is resulting in a significant increase in total CO2 concentration in Earth's atmosphere. However, the ratio of 14C to 12C is decreasing. Why is this?

Fossil fuels are so old that any 14C in the starting organic matter has decayed.

What additional information would assist you in determining whether polar bears and grizzlies are different species, based on the biological species concept? I. whether the F1 is fertile II. whether F1 offspring are viable III. the amount of DNA sequence divergence between polar and grizzly bears IV. the geographic distribution of polar and grizzly bears

I. whether the F1 is fertile II. whether F1 offspring are viable

Why was the theory of blending inheritance eventually disproven?

It was eventually disproven by demonstrating segregation of alleles for the inheritance of many traits in diverse types of organisms

What is true regarding linked genes?

Linked genes are located in the same chromosome and do not follow patterns of independent assortment

During the end-Permian mass extinction:

Oceans were acidified as a result of volcanic eruptions, oxygen levels in the deep oceans dropped, & global warming occurred as a result of volcanic eruptions.

For an individual who is heterozygous for two genes, Aa and Bb, what does independent assortment predict?

Offspring inheriting the dominant (A) allele of the first gene are equally likely to inherit either the dominant (B) or the recessive (b) allele of the second gene.

paraphyletic

Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.

monophyletic

Pertaining to a taxon derived from a single ancestral species that gave rise to no species in any other taxa.

_____ is a term that refers to multiple sets of chromosomes (e.g., 4, 6 or 8).

Polyploidy

Why is the raw measurement of 14C inaccurate for predicting the age of a fossil?

The abundance of 14C in the atmosphere has varied over time.

Which of the following statements describes populations that are genetically isolated?

They do not exchange genetic material

Which of the following represents genetic incompatibility?

Two groups of snakes do not produce fertile offspring because they have a different number of chromosomes.

A node on the phylogenetic tree indicates:

a branch point and common ancestor.

A gene pool is compromised of all of the:

alleles in a population

A molecular clock is:

an estimate of the rate of accumulation of genetic divergence between two populations or species.

Recall that alleles of a single gene will segregate from one another during anaphase I. When do alleles for two different genes—located on two different chromosomes—segregate?

anaphase I

Animals that sexually reproduce are ________ and produce __________ gametes.

diploid; haploid

Speciation has occurred when:

divergent populations evolve to the point where interbreeding does not produce viable, fertile offspring.

A neutral mutation is one that:

does not affect survival or reproduction.

The _____________ two loci are on a chromosome, the more likely they will be separated by crossover events during gamete formation, and thus the frequency of recombination between loci on a chromosome can be used to measure the _______________ between those loci.

farther apart; genetic distance

Map distances (and recombination frequencies) are additive:

for distances up to about 15 map units, at which point recombination frequency becomes lower than expected.

While we can use molecular clocks based on molecular sequence data to estimate the times at which various lineages diverged, we ultimately need the _____ to calibrate the clocks.

fossil records

According to recent studies, the human malaria parasite Plasmodium falciparum was introduced to humans from:

gorillas

A researcher has sequenced a patient's Y chromosome. The sequence constitutes this particular Y chromosome's:

haplotype or haploid genotype

One reason we see relatively little genetic variation among human regional populations is that:

humans migrated out of Africa so recently that we haven't had enough time for regional variation to accumulate.

The Biological Species Concept is least useful for:

identifying species represented by fossils

The biological species concept states that species are actually or potentially _____ populations that are reproductively isolated from other such groups.

interbreeding

Imagine a scenario in which a common population of animals is separated into two groups by a natural event. Over time, you might expect the two populations to become ______ genetically similar. This process is known as _____ speciation.

less; allopatric

How does the level of genetic variation in humans compare to the level of genetic variation in other species?

lower than other species

Nonadaptive mechanisms of evolutionary change are:

migration (gene flow), mutation, and genetic drift.

Statistical analysis of genetic variation within and among human populationsincluding those we identify as different racesreveals:

more genetic variation within groups than we see between groups.

Genetic variation in a population refers to:

multiple alleles within a gene pool

The continued high frequency of the sickle allele (S) of hemoglobin in Africans, in some Mediterranean populations, and in populations descended recently from Africans is a reflection of the response of human populations via _____ to a regional disease.

natural selection

The _____ level of the taxonomic hierarchy is more inclusive than a family, but less inclusive than a class.

order

In humans or other animals, material inheritance is characteristic of mitochondrial diseases that often affect _______ phosphorylation.

oxidative

polyphyletic

pertaining to a group of taxa derived from two or more different ancestors

Which of the following species concepts might differentiate species on the basis of descent from a common ancestor?

phylogenetic species

A taxon that does NOT include the last common ancestor of all its members is a _____ group.

polyphyletic

When taxonomists recognize subspecies, they are identifying:

populations with restricted enough gene flow to develop some population-specific traits, but that can still interbreed with members of other such populations.

What is the definition of neoteny?

retention of juvenile characteristics in an adult

All else being equal, selection should more strongly favor reinforcement of reproductive isolation among related species in:

sympatric populations over allopatric populations.

Traits that are shared by more than one member of a group because of common ancestry are known as:

synapomorphies.

A researcher is trying to determine whether different populations of asexually reproducing bacteria belong to the same species. What concept will be most helpful in making this determination?

the ecological species concept

Which of the following factors would be least likely to affect the mutation rate in a population?

the level of recombination in a population

The principle of independent assortment holds that:

the pattern of inheritance of one trait does not influence the pattern of inheritance of another trait.

The wide variety of finches Darwin observed in the Galápagos was thought-provoking because they appeared to have descended from _____ population. Today we regard this as an example of _____.

the same; adaptive radiation

When several possible phylogenetic trees can be produced from a data set, the most parsimonious tree is the one that shows the:

the smallest number of evolutionary changes

The term "modern synthesis" refers to:

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

Vicariance is defined as:

when a geographic barrier arises that isolates two populations.