ZOOL 304

Answers to Study Questions

Here are answers (and some explanations) for the study questions.

Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

Notes for chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Prologue and Chapter 1.  

In this set are only those questions missed on the in-class quiz.  Correct answers are bold.

  1. Which pair of circumstances below would most strongly increase the probability that male submission to sexual cannibalism would evolve as an adaptive reproductive strategy?  (Be prepared to explain or justify your answer.)
    1. Multiple mating opportunities for most males.
    2. Very few mating opportunities for most males.
    3. Reliable nutritional resources (prey) for most females.
    4. Limited nutritional resources (prey) for most females.
      Explanation:  You can analyze this case in terms of "residual reproductive value", a concept introduced on text p. 39.  If each male is unlikely to mate more than once (i.e., very low residual reproductive value), any action which increased the productivity of the initial mating would probably be advantageous.  If females were undernourished, consuming the male could increase her egg-laying potential (and thus increase the reproductive value of the male's current effort).  But if females were well-nourished, a male's sacrifice would not matter much (i.e., no substantial increase in current reproductive value, with absolute loss of future reproduct value). 
       
  2. Which of the following fish species is prey to the other two, in the Aripo River watershed of Trinidad?  
    1. Guppies (Poecilia reticulata)
    2. Large cichlids (Crenicichla alta)
    3. Small killifish (Rivulus hartii)
      See text p. 2-3 for details.
       
  3. Under strong selection, how quickly may adaptively significant traits evolve?  (Obviously, this may depend on the particular traits in question.  Choose an answer based on the example in the textbook prologue.)
    1. millions of years.
    2. thousands of years.
    3. hundreds of years.
    4. tens of years, or even less.
      Although this answer may be surprising, adaptive evolution can operate quite rapidly under appropriate circumstances (availability of variation, strong selection).  The much-vaunted slowness of evolution is perhaps more puzzling.  It is probably best explained by inconstancy of directional selection (i.e., long periods during which selection either fluctuates back and forth [as has been observed for Galapagos finches; see p. 88] or is stabilizing.  Another potentially rate-limiting process may be the origin of appropriate new variation by mutation.
       
  4. Pentastomids are parasites of:  
    1. herbivorous insects.
    2. various vertebrates.
    3. vascular plants.
    4. algae.
      (See the text, p. 4.)
       
  5. Which example is cited by the text as evidence for the importance of history?  
    1. sexual cannabilism by spiders
    2. adult size and maturation rate of guppies
    3. irreversibility of the evolution of inner-ear bones
      (See text for explanation, pp. 5-6.)
       
  6. "Two concepts and a link between them explain microevolution.  The two concepts are heritable variation in traits and variation in reproductive success among individuals within a population.  The link is the correlation between the two types of variation."   Neutral evolution occurs when this correlation is:
    1. positive.
    2. negative.
    3. zero (or approximately zero).
       With either positive or negative correlation (i.e., when particular trait values are statistically associated either with greater or with lesser reproductive success), adaptive evolution is occurring (i.e., the differences in reproductive success constitute selection). But with zero correlation, selection does not operate and any evolutionary change is neutral (NOT adaptive).  
       
  7. "You may have heard that evolution is concerned with survival of the fittest. That is a misleading half-truth.  Survival is important, but only in so far as it contributes to:
    1. speciation."
    2. microevolution."
    3. reproductive success."
    4. adaptation."
      Everyone answered this question correctly.  Thank you!
       
  8. Which correlation provides a measure of heritability?
    1. offspring trait value with parent trait values
    2. reproductive success with parental trait values
    3. reproductive success with offspring trait values
    4. parental trait values with environmental variation
      Heritability is a measure for inheritance (i.e., of genetically-dependent trait values).  If phenotypic variation is heritable, it means that offspring show a better-than-chance resemblance to their parents.
       
  9. With a selective advantage of a few percent (text example, the gene for lactose tolerance), it may take several hundred generations for a rare allele to increase in frequency until it is the most common allele. This illustrates which of the following types of constraint on adaptation?
    1. sufficient time
    2. gene flow
    3. functional tradeoffs
    4. historical constraint
      Please see text for explanations of constraint based on sufficient time, gene flow, functional tradeoffs, and history (pp. 17-18, 15-16, 24-25, and 25-27, respectively).
       
  10. A local population (text example, the blue tit) may fail to evolve fitness to the local environment because individuals adapted to a neighboring but different environment keep immigrating into the region. This illustrates which of the following types of constraint on adaptation?
    1. sufficient time
    2. gene flow
    3. functional tradeoffs
    4. historical constraint
      Please see text for explanations of constraint based on sufficient time, gene flow, functional tradeoffs, and history (pp. 17-18, 15-16, 24-25, and 25-27, respectively).
       
  11. Some features in animal bodies appear to be "design flaws", reflecting the consequences of descent from an ancestral character state rather than any association with current reproductive success. This illustrates which of the following types of constraint on adaptation?
    1. sufficient time
    2. gene flow
    3. functional tradeoffs
    4. historical constraint
      Please see text for explanations of constraint based on sufficient time, gene flow, functional tradeoffs, and history (pp. 17-18, 15-16, 24-25, and 25-27, respectively).
       

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

In-class Quiz over Chapter 2.  Correct answers are bold.

  1. Which example was used to illustrate coevolution?
    1. clutch size in kestrels
    2. aminopeptidase in mussels
    3. corolla tubes in orchids (see p. 40)
    4. cyanogenesis in Lotus corniculatus
       
  2. Which example was used to illustrate measured variation in allele frequency?
    1. clutch size in kestrels
    2. aminopeptidase in mussels (see p. 41)
    3. corolla tubes in orchids
    4. cyanogenesis in Lotus corniculatus
       
  3. Lotus corniculus is a:
    1. mollusc.
    2. bird.
    3. flowering plant (illustrated in Fig. 2-3, p. 38)  [Link to photo and description]
    4. fungus.
       
  4. For each pair below, which would be expected to increase the rate of adaptive microevolution?
    1. population size [ large / small ]
    2. variation [ lots / little ]
    3. selection [ strong / weak ]
    4. generation time [ long / short ]
      Actually, population size may go either way.  In the simplest terms (i.e., all else being equal), more variation should emerge in a large population (more opportunities for mutation) and this should provide more raw material for adaptive evolution.  But all else is seldom equal.  Small populations may be subjected to stronger and more consistent selection pressures, which may increase the rate of adaptive change.  Furthermore, inbreeding in small populations may expose recessive alleles to selection, again increasing the rate of adaptive change.
         
  5. Which type of selection acts through greater reproductive success of individuals closer to the population average?
    1. stabilizing selection (see fig. 2-9, p. 48)
    2. directional selection
    3. disruptive selection
       
  6. Which type of selection acts through greater reproductive success of individuals on one side of the population average?
    1. stabilizing selection
    2. directional selection (see fig. 2-9, p. 48)
    3. disruptive selection
       
  7. Competition for access to mates (usually among males) and mate choice (usually by females) are responsible for a process called:
    1. sexual cannibalism
    2. sexual reproduction
    3. sexual recombination
    4. sexual selection (see p. 45-47)
       
  8. Which type of selection involves traits for which the fitness contribution of one variant depends on the prevalence within the population of other variants?
    1. density-dependent selection
    2. density-independent selection
    3. frequency-dependent selection (see p. 49)
    4. frequency-independent selection
       
  9. Which type of selection involves traits which directly impact the maximal rate at which population size can increase?
    1. density-dependent selection (see p. 48 and link)
    2. density-independent selection
    3. frequency-dependent selection
    4. frequency-independent selection
       
  10. Which type of selection occurs through differential rates of speciation and extinction?
    1. individual selection
    2. kin selection
    3. group selection
    4. species selection (see p. 49-50)
       
  11. Which type of selection is based on interactions among relatives, with fitness increased by assisting the reproduction of siblings, cousins, etc.?
    1. individual selection
    2. kin selection (see p. 49-50)
    3. group selection
    4. species selection
       
  12. Which type of selection is responsible for most adaptive features of most organisms?
    1. individual selection (see p. 49-50)
    2. kin selection
    3. group selection
    4. species selection

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

Additional Exam Questions

304 index page

Study questions for Chapter 3.  Correct answers are bold.

  1. "Fitness", as used in evolutionary biology, is a synonym for:
    1. natural selection.
    2. relative reproductive success.
    3. adaptation.
    4. probability of survival.
       
  2. By definition, "neutral" alleles are those where allele differences are NOT correlated with differences in:
    1. fitness.
    2. genotype.
    3. phenotype.
    4. evolution.
       
  1. Which pair of codons are synonymous?
    1. GGT and GTT
    2. GGT and GGC
    3. GGT and CGT
    4. GGT and GCT
       
  2. Which codon substitution is "silent" (no change in the encoded protein)?
    1. CAG to CAC
    2. CAG to GAG
    3. CAG to CTG
    4. CAG to TAG

Find the codons in the table; see whether or not they code for the same amino acid.
TTT Lys
TTG Asn
TTC Lys
TTA Asn
TGT Thr
TGG Thr
TGC Thr
TGA Thr
TCA Arg
TCG Ser
TCC Arg
TCA Lys
TAT Ile
TAG Ile
TAC Met
TAA Ile
GTT Gln
GTG His
GTC Gln
GTA His
GGT Pro
GGG Pro
GGC Pro
GGA Pro
GCT Arg
GCG Arg
GCC Arg
GCA Arg
GAT Leu
GAG Leu
GAC Leu
GAA Leu
CTT Glu
CTG Asp
CTC Glu
CTA Asp
CGT Ala
CGG Ala
CGC Ala
CGA Ala
CCT Gly
CCG Gly
CCC Gly
CCA Gly
CAT Val
CAG Val
CAC Val
CAA Val
ATT stop
ATG Tyr
ATC stop
ATA Tyr
AGT Ser
AGG Ser
AGC Ser
AGA Ser
ACT stop
ACG Cys
ACC Trp
ACA Cys
AAT Leu
AAG Phe
AAC Leu
AAA Phe

   
  1. Base substitutions at which codon position are most likely to yield neutral mutations?
    1. first position
    2. second position
    3. third position This is the position that varies among most pairs of synonymous codons.
       
  2. Which of the following refers to a DNA sequences within a eucaryotic gene that is removed prior to translation into protein?  If you don't know this terminology, you should learn it as part of basic biological vocabulary.
    1. synonymous substitution
    2. intron
    3. exon
    4. pseudogene
       
  3. Different classes of DNA sequence evolve (accumulate molecular changes) at different rates.  Which of the following shows the fastest rate of evolutionary change?
    1. pseudogenes
    2. introns
    3. exons
      Exons specify protein segments, so mutations are likely to be deleterious (i.e., their evolution is constrained by function).  Introns are within functional genes, so mutations here may also be deleterious (although commonly less so than in exons).  Pseudogenes have no function, so mutations have no deleterious effect and can accumulate freely.
               
  4. Which of the following shows the slowest rate of evolutionary change?
    1. pseudogenes
    2. introns
    3. exons  See explanation above.
       
  5. Which of the following is responsible for non-random genetic change?
    1. selection  All of the other processes below are essentially random (undirected) in their effects, based on statistical chance and fluctuations.  Selection IS the NON-random preferential of certain genotypes based on their fitness.
    2. mutation
    3. the "Mendelian lottery"
    4. genetic bottlenecks
    5. founder effects
       
  6. Random genetic change in the genetic composition of a population [caused by statistical fluctuations] is called:
    1. natural selection.
    2. mutation.
    3. adaptation.
    4. genetic drift by definition.
       
  7. The "Mendelian lottery" refers to chance events during:
    1. directional selection.
    2. genetic bottlenecks.
    3. meiosis and fertilization by definition.
    4. founder events.
       
  8. The Hardy-Weinberg principle [see Chapter 4] predicts that under idealized circumstances, including indefinitely large population size, allele frequencies should not change over time.  However, the frequencies of neutral [or nearly neutral] alleles in real, finite populations are statistically expected to change.  This statistical expectation is called:
    1. natural selection.
    2. mutation.
    3. adaptation.
    4. genetic drift by definition.
       
  9. From one generation to the next, any given neutral allele is expected to:
    1. increase in frequency within the population.
    2. decrease in frequency within the population.
    3. either increase or decrease in frequency within the population, with equal probability.  This is how genetic drift works.
    4. either increase or decrease in frequency within the population, depending on its initial frequency.
       
  10. Given enough time, the expected result for genetic drift is that the frequency of any given neutral allele will:
    1. increase steadily until the allele is eliminated from the population.
    2. decrease steadily until the allele becomes fixed in the population.
    3. fluctuate randomly until the allele is either eliminated or fixed, with equal probability.
    4. fluctuate randomly until the allele is either eliminated or fixed, with a probability that depends on its initial frequency.  This is how genetic drift works.  See genetic drift for extended discussion.
       
  11. Over extended time, genetic drift acting alone [without mutation to introduce new alleles] is expected to:
    1. maintain genetic variation within a population.
    2. increase genetic variation within a population.
    3. reduce or eliminate genetic variation within a population.  This is how genetic drift works.  See genetic drift for extended discussion.
         
  12. If several populations begin by splitting from a single ancestral population, so that initially each has the same pattern of variation in many different alleles, over extended time, genetic drift acting alone [without mutation to introduce new alleles] is expected to:
    1. maintain genetic variation among the populations.
    2. increase genetic variation among the populations.  Since alleles are eliminated or fixed at random, the particular results of drift will be differnt in different populations.  Hence, over time, they will diverge.
    3. reduce or eliminate genetic variation among related populations.  
       
  13. The statistically-predictable rate of evolutionary change in DNA or protein molecules is called:
    1. the molecular clock.  See text, p. 68.
    2. the genetic bottleneck.
    3. neutral evolution.
    4. adaptive evolution.
       

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 4.  Correct answers are bold.

  1. *An example of a sexual organism with a predominantly haploid life cycle is a:
    1. bacterium.
    2. fruit fly.
    3. moss.  The most prominent portion of the bryophyte life cycle (the familiar little green moss plant) is haploid. The haploid moss plants, called gametophytes, produce haploid gametes by ordinary cell division (mitosis).  The active male gametes swim in surface moisture from the male plants to the female plants, where fertilization occurs.  The diploid zygote stays in the female plant, where it grows into the diploid sporophyte.  Familiar moss sporophytes are thin brown stalks, each with a capsule at the end.  Meiosis occurs within the diploid sporophyte, forming haploid spores.  The haploid spores are then scattered by the wind; if fortunate, they germinate into new haploid gametophyte moss plants.
    4. rotifer.
       
  2. *An example of an asexual organism with a predominantly haploid life cycle is a:
    1. bacterium.  All prokaryotes (does anyone know of an exception?) are haploid.  Period.
    2. fruit fly.
    3. moss.
    4. rotifer.
       
  3. *An example of a sexual organism with a predominantly diploid life cycle is a:
    1. bacterium.
    2. fruit fly.  Most familiar animals (including all vertebrates) are composed of diploid cells.  Only the gametes are haploid, and these generally do little except fertilize one another to form diploid zygotes, which grow by mitosis into diploid animals.  But just because this pattern is so familiar, don't forget that biology is rich and varied.  Plants, especially algae and the "lower" land plants, follow rather different patterns.  Protozoa have some really weird reproductive systems, and some "higher" animals are alo rather various.
    3. moss.
    4. rotifer.
       
  4. *An example of an asexual organism with a predominantly diploid life cycle is a:
    1. bacterium.
    2. fruit fly.
    3. moss.
    4. rotifer. Examples of asexual diploids are rare and puzzling.  Most animals which reproduce entirely parthenogenetically (without meiosis and fertilization) have evolved rather recently from "normal" sexual ancestors.  The general presumption is that sexual reproduction may be abandoned because of the tremendous cost of sex, but that such loss leads to an evolutionary "dead end" (see chapter 7).  Rotifers are notorious because their asexual lineages appear to be relatively ancient.
       
  5. In sexual organisms with a prodominantly diploid life cycle, the process of meiosis produces:
    1. haploid gametes.  See note for question 3 above.
    2. diploid gametes.
    3. haploid zygotes.
    4. diploid zygotes.
       
  6. In sexual organisms with a prodominantly diploid life cycle, the process of fertilization produces:
    1. haploid gametes.
    2. diploid gametes.
    3. haploid zygotes.
    4. diploid zygotes.  See note for question 3 above.
       
  7. In haploid asexual populations, genetic change from selection occurs _____ in diploid sexual populations.
    1. ... faster than ...  There are no recessive alleles "hiding" from selection.
    2. ... slower than ...
    3. ... at the the same rate as ...
       
  8. In the equation [ w  =  p2 + 2pq x (1 + hs) + q2 x (1 + s) ], the variables p and q stand for:
    1. mean fitness values.
    2. allele frequencies.
    3. selection coefficients.
    4. heritability values.
       
  9. In the equation [ w  =  p2 + 2pq x (1 + hs) + q2 x (1 + s) ], the variable w stands for:
    1. mean fitness.
    2. allele frequency.
    3. selection coefficient.
    4. heritability.
       
  10. In the equation [ w  =  p2 + 2pq x (1 + hs) + q2 x (1 + s) ], the variable s stand for:
    1. mean fitness.
    2. allele frequency.
    3. selection coefficient.
    4. heritability.
       
  11. As shown in the Punnett square of Table 4.3, the expected Hardy-Weinberg genotype frequencies are found by _____ the frequencies of the alleles which comprise the genotype.
    1. ... adding ...
    2. ... subtracting ...
    3. ... multiplying ...
    4. ... dividing ...
       
  12. If s is positive, and the fitness of genotype [aa] is 1+s , and other genotypes have fitness of 1, the frequency of allele a is expected to:
    1. increase.  This is what a positive selective coefficient is all about.
    2. decrease.
    3. fluctuate with no expected trend.
    4. remain close to the Hardy-Weinberg equilibrium value.
       
  13. Regardless of whether an allele is dominant or recessive or advantageous or deleterious, the rate of genetic change from selection is most rapid when the allele's frequency is:
    1. very low.
    2. very high.
    3. intermediate.  Remember, "slow - fast - slow" (text p. 79).  
       
  14. In sexual diploids, the initial increase of a beneficial allele is much faster when the allele is:
    1. dominant.
    2. recessive.  At very low frequency, a recessive allele occurs only in heterozygous genotypes where it is invisible to selection.  Selection cannot begin to favor a beneficial recessive until it first drifts to high enough frequency that homozygotes appear in the population.
       
  15. In sexual diploids, the final elimination of a deleterious allele is faster when the allele is:
    1. dominant.
    2. recessive.  The final elimination of a deleterious recessive occurs by random drift.  At very low frequency, a recessive allele occurs only in heterozygous genotypes where it is invisible to selection.  Selection can prevent the allele from increasing by drift, but the final elimination is by chance.
       
  16. The statistical measure of variation (see chapter notes) which is equivalent to the square of the standard deviation is the:
    1. mean.
    2. mode.
    3. average.
    4. variance.
       
  17. Phenotypic variance (var P) is what function of genetic variance (var G) and environmental variance (var E)?
    1. sum:  var G + var E  By definition, the total phenotypic variance consists of all the variance caused by genetic differences and by environment.
    2. difference:  var G - var E
    3. product:  var G x var E
    4. quotient:  var G / var E
       
  18. Heritability (h2) may defined as which relation between genetic variance (var G or var A) and phenotypic variance (var P)?
    1. var G + var P
    2. var G - var P
    3. var G x var P
    4. var G / var P  Genetic variance is the proportion of phenotypic variance that is due to heredity.
       
  19. Heritability (h2) may also be defined by what relation between selection differential (S) and response to selection (R)?
    1. R + S
    2. R - S
    3. R x S
    4. R / S  This answer is related to the answer to the previous question.  The selection differential is a measure based on phenotypic variation (in truncation selection, it is the difference between the means of the starting population and the population remaining after selection).  The response to selection is the proportion of that change which is perpetuated into the next generation.
       
  20. In "truncation selection" (see Fig. 4-10), the difference between the original population mean and the mean of those which reproduce is called the:
    1. environmental variance.
    2. genetic variance.
    3. selection differential.  by definition
    4. response to selection.
       
  21. In "truncation selection" (see Fig. 4-10), the difference between the mean of the original population and the mean of the next generation after selection is called the:
    1. environmental variance.
    2. genetic variance.
    3. selection differential.
    4. response to selection.  by definition
       
  22. If a trait is strongly selected, genetic variation will be reduced due to fixation of advantageous alleles.  As a result, additive genetic variance will be ___ and heritability will be ____ .
    1. ... var A increased ... heritability increased ...
    2. ... var A increased ... heritability decreased ...
    3. ... var A decreased ... heritability increased ...
    4. ... var A decreased ... heritability decreased ...  Eliminating genetic variants necessary reduces genetic variance; heritability is proportional to genetic variance (see question 18 above), so decreasing genetic variance necessarily decreases heritability.
       
  23. Traits with higher heritabilities respond to selection:
    1. faster.  The higher the heritability, the more genetic variance.  The more genetic variance, the more basis for selection.  Conversely, with traits whose genetic variance is low also (by definition) have low heritability, and there is less basis for selection.
    2. slower.
    3. Heritability does not affect the response to selection.
       
  24. TRUE or FALSE:  Heritability is a measure of the extent to which a trait is determined by genes.
    1. true
    2. FALSE  Heritability is nothing more than the proportion of phenotypic variance which is due to genetic variance.  "Determined by genes" is a fairly meaningless phrase.  Red lights should flash, and alarms sound, whenever you encounter this phrase.
       
  25. For traits which show high heritability, the shift in population mean after strong directional selection over many generations:
    1. cannot exceed the standard deviation (square root of variance) of the original population.
    2. can be many times the standard deviation of the original population.  Remarkable, but true.  The outcome of strong directional selection in any particular case depends on the genetic basis for genetic variance, which is polygenic and polyallelic in many natural populations.
       
  26. Heritability measures apply only to the particular population and environment in which they are taken.  The heritability of a trait in a small, local, inbred population is likely to be ___ that in a large, widespread, outbreeding population.
    1. ... lower than ...  Heritability is proportional to genetic variance, which is likely to be low in a small inbred population.
    2. ... higher than ...
    3. ... the same as ...
       
  27. TRUE or FALSE:  If heritability of a trait is high within each of two populations, the difference in mean trait value between those two populations indicates a genetic difference between the two.
    1. true
    2. FALSE  Any measure of heritability applies only to the population in which it is measured.  Differences between populations may be due either to genetic differences or to environmental differences, or both.  Only carefully controlled experiment can determine which.
       
  28. A Quantitative Trait Locus (QTL) for a trait is a chromosomal site which:
    1. contributes to quantitative genetic variation in that trait.
    2. determines the phenotypic value for a trait.
    3. has a measured DNA sequence length.

End of Chapter problems.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 5.  Correct answers are bold.

Hints for end-of-chapter questions.

  1. The genetic term "wild type" refers to an individual in which alleles at each locus :
    1. are natural.
    2. combine into unique chromosomal haplotypes.
    3. correspond to predominant alleles in a natural population.
    4. have not mutated.
       The term "wild type" is used in experimental genetics but really has little place in evolutionary biology.  See further discussion in Chapter 5 notes.
       
  2. Measurement (in mice, humans, and Drosophila) of deleterious mutations suggests that mutations of large effect occur at a rate of about:
    1. 1 in 10 gametes.
    2. 1 in 1000 gametes.
    3. 1 in 100,000 gametes.
    4. 1 in 10,000,000 gametes.
       See text page 94.  Note that mutation rates are highly variable and difficult to measure.
       
  3. Measurement (in humans and Drosophila) of mildly deleterious mutations suggests that recessive mutations of small effect occur at a rate of about:
    1. 1 in each zygote.
    2. 1 in 1000 zygotes.
    3. 1 in 1,000,000 zygotes.
    4. 1 in 1,000,000,000 zygotes.
       See text page 95.  Note that mutation rates are highly variable and difficult to measure.
       
  4. Mutation rates are commonly:  CORRECTED, 26 Feb.
    1. higher in males than in females.
    2. higher in females than in males.
    3. the same in both sexes.
      This is presumably related to the greater number of cell divisions needed to produce vast numbers of sperm.
       
  5. Haplotypes are:
    1. haploid multi-locus genotypes.
    2. multiploid haplo-locus genotypes.
    3. genoid haplo-locus multitypes.
    4. haploid geno-locus multitypes.
      The other terms are all nonsense.
       
  6. The proportion of a population which is heterozygous at a particular locus is called:
    1. haplo-diploidy.
    2. heterozygosity.
    3. heterosis.
    4. frequency dependence.
      This and the following question offer two different ways to define (and measure) heterozygosity.  
       
  7. The average proportion of loci which are heterozygous in an individual is called:
    1. haplo-diploidy.
    2. heterozygosity.
    3. heterosis.
    4. frequency dependence.
      This and the preceding question offer two different ways to define (and measure) heterozygosity.
       
  8. Measures of molecular polymorphism detected levels of genetic diversity which were:
    1. consistent with previous expectations.
    2. much lower than previously expected.
    3. much higher than previously expected.
      Before anyone actually could measure allele polymorphism, it was presumed that selection would maintain a single most-advantageous "wild type" allele at most loci, except in special (rare) cases of heterozygote advantage.
       
  9. The neutral theory of molecular genetic variation is associated with the name of:
    1. Darwin.
    2. Mendel.
    3. Kimura.
    4. Hardy and Weinberg.
       
  10. Measured levels of molecular genetic variation can be explained:
    1. better by genetic drift (neutral evolution).
    2. better by adaptive evolution.
    3. both by genetic drift and by selection.
      There is not yet consensus on the extent to which molecular genetic variation is best explained, except general agreement that both mechanisms are involved.
       
  11. If u is the rate at which neutral mutations appear in an individual locus, and N is the population size, what is the theoretical rate at which neutral mutations at the locus drift to fixation within the population?
    1. Nu
    2. 2Nu
    3. u / 2N
    4. u
      This is one of the simplest results from population genetics, that the rate at which neutral alleles are fixed in a population by drift is equal to the rate at which they appear in individuals.
       
  12. In the equation for mutation-selection balance with a dominant mutation, q = u / s , the variable u stands for:
    1. allele frequency.
    2. heterozygote advantage.
    3. selection coefficient.
    4. mutation rate.
       
  13. In the equation for mutation-selection balance with a dominant mutation, q = u / s , the variable s stands for:
    1. allele frequency.
    2. heterozygote advantage.
    3. selection coefficient.
    4. mutation rate.
       
  14. If a recessive lethal (fitness = 0) mutation occurs at a rate of 10-6 per gene per generation, what is the expected frequency of the mutant allele at mutation-selection equilibrium?       q = square root ( u / s )
    1. 1 in 100
    2. 1 in 1000
    3. 1 in 10,000
    4. 1 in 100,000
    5. 1 in 1,000,000
      According to the equation provided, the allele frequency (      q) is equal to the square root of [the mutation rate (10-6) divided by the selection coefficient (s)].  For lethal genotypes, s is 1.
       
  15. If a recessive lethal (fitness = 0) mutation occurs at a rate of 10-6 per gene per generation, what is the expected frequency of the disease (homozygous genotype) at mutation-selection equilibrium?        q = square root ( u / s )
    1. 1 in 100
    2. 1 in 1000
    3. 1 in 10,000
    4. 1 in 100,000
    5. 1 in 1,000,000
      The answer to the previous question gives the allele frequency (      q) under these conditions.  The frequency of the disease is the frequency of the homozygous genotype before selection, which is q2.
       
  16. If a dominant lethal (fitness = 0) mutation occurs at a rate of 10-6 per gene per generation, what is the expected frequency of the mutant allele at mutation-selection equilibrium?        q = u / s
    1. 1 in 100
    2. 1 in 1000
    3. 1 in 10,000
    4. 1 in 100,000
    5. 1 in 1,000,000
      According to the equation provided, the allele frequency (q) is equal to the the mutation rate (10-6) divided by the selection coefficient (s).  For lethal genotypes, s is 1.  Thus, unsurprisingly, for dominant lethal alleles the occurrence of the disease is exactly equal to the mutation rate (i.e., every occurrence of the mutation appears as a case of the disease, and that particular example of the mutant allele is then eliminated from the population).
       
  17. Deleterious mutations may be retained at appreciable frequency within a population by:
    1. mutation-drift balance.
    2. mutation-selection balance.
    3. heterosis (heterozygote advantage).
    4. frequency-dependent selection.
       
  18. The frequency at which mutation-selection balance maintains alleles associated with a deleterious phenotype is:
    1. greater for dominant than recessive alleles.
    2. greater for recessive alleles than for dominant alleles.
    3. unaffected by allele dominance.
      Mutation introduces mutant alleles at low frequency.  Selective removal of low-frequency dominant alleles is much more efficient than selective removal of low-frequency recessives.
         
  19. If a genetic disease is caused by a recessive allele, and the disease occurs in 1 in 4000 individuals, what is the frequency of the recessive allele in the population?
    1. 1 in 63
    2. 1 in 200
    3. 1 in 400
    4. 1 in 4000
      Oops!  The answer originally posted was incorrect.  My arithmetic skills leave a bit to be desired.  The prevalence of the disease is the frequency of the homozygous recessive genotype, which (by the Hardy-Weinberg frequencies) is the square of the allele frequency.  (1 in 4000 is the square of 1 in 63.)
       
  20. The alleles which cause certain human genetic diseases, including sickle-cell anemia and cystic fibrosis, occur at relatively high frequencies.  It is believed that such high frequencies reflect conditions of:
    1. mutation-drift balance.
    2. mutation-selection balance.
    3. heterosis (heterozygote advantage).
    4. frequency-dependent selection.
      If severely deleterious recessive mutations at a locus occur at a rate of about 1 mutation in 100,000 copies of the allele, then mutation-selection balance is expected to maintain these alleles at a frequency of about 1 in 300 (i.e., at equilibrium the expected allele frequency for lethal recessives is the square root of the mutation rate).  This, in turn, leads to disease prevalence (i.e., the frequency homozygous genotypes) approximately equal to the mutation rate.  For disease prevalence much higher than this, some explanation other than mutation-selection must obtain.  For more, see discussion for end-of-chapter questions.
       
  21. Under conditions of heterozygote advantage, the equilibrium allele frequencies depend most directly on:
    1. the selection coefficient of the lower-frequency homozygote.
    2. the selection coefficient of the higher-frequency homozygote.
    3. the selection coefficient of the heterozygote.
    4. the proportion by which selection coefficient of the heterozygote exceeds that of the more-fit homozygote.
      The population-genetics equation for the equilibrium allele frequency under conditions of heterozygote advantage (see page 104) does not include the selection coefficient.  Selection can be weak or strong.  What matters is the proportion by which selection coefficient of the heterozygote exceeds that of the more-fit homozygote.

       
  22. When two or more alleles are maintained at fairly high frequencies because the fitness of each genotype depends on on the prevalence within the population of other genotypes, this condition is called:
    1. mutation-drift balance.
    2. mutation-selection balance.
    3. heterosis (heterozygote advantage).
    4. frequency-dependent selection.
      For more, see Chapter 5 notes.

End-of-chapter questions 5.1, 5.2, 5.3 and 5.4.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 6.  None.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 7.  (Notes for Chapter 7)  Correct answers are bold.

 

  1. What is the genetic cost of sex?
    1. 95%
    2. 90%
    3. 50%
    4. 10%
    5. 5%
       
  2. The condition of reproducing with unequal gametes (e.g., eggs and sperm) is called :
    1. diploidy.
    2. haploidy.
    3. haplo-diploidy.
    4. meiosis
    5. anisogamy.
       
  3. Genetic recombination in procaryotes involves:
    1. zygote formation.
    2. haplontic reproduction.
    3. diplontic reproduction.
    4. conjugation (with unequal exchange of genetic material).
    5. apomixis.
       
  4. A life cycle in which sexual reproduction alternates with asexual reproduction is called:
    1. haplontic.
    2. diplontic.
    3. cyclical parthenogenesis.
    4. apomixis.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

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Study questions for Chapter 8.  Correct answers are bold.

    FOR QUESTIONS 1 through 3, choose the member of each pair which would confer greater fitness, presuming no other considerations.  That is, in competition, which trait would be expected to confer greater reproductive success?

  1. Number of offspring during each reproductive cycle:
    1. more offspring
    2. fewer offspring
  1. Length of time from birth to first reproductive cycle:
    1. longer time to maturity
    2. shorter time to maturity
         
  2. Life span (total number of reproductive cycles after maturity):
    1. longer life span
    2. shorter life span
       
      *****
      FOR QUESTIONS 4 through 10, choose the member of each trait pair which would result as a tradeoff from the listed change.
       
  3. Increase investment of resources in each individual offspring:
    1. more offspring.
    2. fewer offspring.
       
  4. Decrease investment of resources in each individual offspring:
    1. greater probability of survival for each offspring.
    2. lower probability of survival for each offspring.
       
  5. Increase number of offspring in a given reproductive cycle:
    1. increased probability of future reproduction by the same parent.
    2. reduced probability of future reproduction by the same parent.
       
  6. Increase number of offspring in a given reproductive cycle
    1. greater probability of survival for each offspring.
    2. lower probability of survival for each offspring.
         
  7. Decrease time to maturation:
    1. smaller mature body size, fewer and/or smaller offspring.
    2. larger mature body size, more and/or larger offspring
       
  8. Increase lifespan:
    1. reduced resources devoted to reproduction.
    2. increased resources devoted to reproduction.
         
  9. Increase mature body size, increased number of offspring:
    1. more resources needed to reach maturity.
    2. reduced resources needed to reach maturity.
         
      *****
       
  10. Which term refers to the balance between costs and benefits?
    1. optimality
    2. allopatry
    3. heterogamy
    4. pleiotropy
       
  11. If natural selection has optimized a trait, a quantitative increase in that trait would be expected to:
    1. increase fitness.
    2. decrease fitness.
    3. have no effect on fitness.
       
  12. If natural selection has optimized a trait, a quantitative decrease in that trait would be expected to:
    1. increase fitness.
    2. decrease fitness.
    3. have no effect on fitness.
       
  13. A gene which affects two or more different traits is said to have:
    1. optimal effect.
    2. allopatric effect.
    3. heterogamic effect.
    4. pleiotropic effect.
         
  14. Genes which show antagonistic pleiotropy are those whose genetic effects cause:
    1. increased fitness in two or more traits.
    2. decreased fitness in two or more traits.
    3. increased fitness through one trait at the expense of decreased fitness through another trait.
         
  15. A co-evolutionary process in which a predator species evolves more effective means of predation while its prey species evolves more effective means of defense is called an evolutionary:
    1. tradeoff.
    2. mutualism.
    3. arms race.
       
  16. The phrase "Lack clutch size" refers to:
    1. the maximal number of eggs which a female bird can produce during one nesting season.
    2. the minimum number of eggs which will assure perpetuation of the species.
    3. the optimum number of eggs which will maximize the number of fledglings.
       
  17. Most species have a characteristic life span which results from tradeoffs between reproduction and survival.  Selection is expected to favor shifting resources away from immediate reproduction in order to increase life span only when the probability of survival from one reproductive season to the next is:
    1. high.
    2. low.
    3. optimal
    4. pleiotropic.
       
  18. R.A. Fisher attributed the prevalence of 50:50 sex ratios to:
    1. frequency dependent selection.
    2. haplo-diploidy.
    3. directional selection.
    4. disruptive selection
         

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 9.  Correct answers are bold.

  1. Competition for access to mates (usually among males) is responsible for a process called:
    1. sexual cannibalism.
    2. sexual reproduction.
    3. sexual recombination.
    4. sexual selection.
       
  2. Mate choice (usually by females) is responsible for a process called:
    1. sexual cannibalism.
    2. sexual reproduction.
    3. sexual recombination.
    4. sexual selection.
       
  3. The "sexy son hypothesis" and the "handicap hypothesis" both relate to reasons underlying:
    1. competition for mates.
    2. mate choice.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 10.  None.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 11.  Correct answers are bold.

  1. Most actual species are identified in practice by:
    1. demonstrated genetic isolation from other populations.
    2. distinct morphological, behavioral, and/or genetic characteristics.
    3. demonstrated descent from a single ancestral population.
       
  2. The concept of species:
    1. is difficult to define, with considerable disagreement over the most suitable criteria.
    2. must be defined in terms of reproductive isolation.
    3. must be defined in terms of ecological niche.
    4. must be defined in terms of descent from a single ancestral population
    5. must be defined in terms of morphological, behavioral and/or genetic characteristics.
       
  3. One of the most popular species concepts, often called the "biological species concept", is based on:
    1. geographic isolation.
    2. ecological isolation.
    3. reproductive isolation.
    4. morphology.
       
  4. The "biological species concept" is commonly attributed to:
    1. Carolus Linnaeus.
    2. Charles Darwin.
    3. Ernst Mayr.
    4. Stephen Jay Gould.
    5. James Watson.
       
  5. Which of the following does NOT create some difficulty for the "biological species concept"?
    1. Asexual organisms.
    2. Interspecies hybridization.
    3. Geographical isolation.
    4. Species-specific mate recognition.
       
  6. "Speciation is a by-product of intraspecific evolution" (text, p. 219).  This means that the evolutionary processes which lead to speciation are:
    1. the same as those (adaptation and drift) which operate to produce change within a species.
    2. are fundamentally different from those which operate to produce change within a species.
       
  7. "Sibling species" are pairs of species which are:
    1. difficult to distinguish from one another.
    2. not reproductively isolated from one another.
    3. created by inbreeding.
    4. created by hybridization of related species.
       
  8. Genetic separation and phenotypic differentiation are two processes involved in:.
    1. hybridization.
    2. speciation.
    3. sexual reproduction.
       
  9. The complete absence of gene flow between two populations is called:
    1. hybridization.
    2. sympatry.
    3. allopatry.
    4. reproductive isolation.
    5. speciation.
       
  10. Suppose that two populations begin by splitting from a single ancestral population, so that initially each has the same pattern of variation in many different alleles.  Over extended time, genetic drift acting alone [without mutation to introduce new alleles] is expected to:
    1. maintain genetic variation between the populations.
    2. increase genetic variation between the populations.  
    3. reduce or eliminate genetic variation between related populations.
       
  11. Processes which prevent mating between members of two different populations are called.
    1. prezygotic (or premating) isolating mechanisms.
    2. postzygotic (or postmating) isolating mechanisms.
    3. hybridization mechanisms.
    4. allopatric isolating mechanism.
    5. sympatric isolating mechanisms.
       
  12. Process which prevent successful reproduction after mating between members of two different populations are called:.
    1. prezygotic (or premating) isolating mechanisms.
    2. postzygotic (or postmating) isolating mechanisms.
    3. hybridization mechanisms.
    4. sympatric isolating mechanisms.
    5. allopatric isolating mechanism.
       
  13. Genetic incompatibility, such as mismatched numbers of chromosomes, which prevents hybrid offspring from surviving or reproducing, is an example of a:
    1. prezygotic isolating mechanism.
    2. postzygotic isolating mechanism.
       
  14. A behavioral trait which assures that only members of one's own population will be recognized as potential mates is an example of a:.
    1. prezygotic isolating mechanism.
    2. postzygotic isolating mechanism.
       
  15. The process by which genetic separation and phenotypic differentiation occur between populations which are geographically isolated from one another is called:
    1. sympatric speciation.
    2. allopatric speciation.
    3. reinforcement.
       
  16. The process by which genetic separation and phenotypic differentiation occur between populations which share the same geographic range is called:
    1. sympatric speciation.
    2. allopatric speciation.
    3. reinforcement.
       
  17. The process whereby two incompletely-isolated populations evolve more-effective genetic isolating mechanisms, on the basis of selection against the reduced fitness associated with cross-breeding, is called.
    1. sympatric speciation.
    2. allopatric speciation
    3. reinforcement.
       
  18. Host shifts in phytophagous insects, divergence in flowering time in plants, and polyploidy are all plausible mechanisms for:
    1. secondary reinforcement.
    2. increasing gene flow.
    3. adaptive hybridization.
    4. sympatric speciation.
       

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 12.  Correct answers are bold.

  1. Evolutionary convergence, parallelism, or reversal is the basis for:
    1. homology.
    2. homoplasy.
    3. plesiomorphy.
    4. synapomorphy.
       
  2. Morphological structures in different taxa which share the same relative position, are built by the same developmental pathways, and (at least by hypothesis) derive their similarity from structures in a common ancestor are called:.
    1. analogies.
    2. convergences.
    3. homoplasies.
    4. homologies.
       
  3. Plesiomorphy and synapomorphy are both terms which refer types of:
    1. homologous similarity.
    2. homoplasious similarity.
    3. convergence.
    4. divergence.
       
  4. Homology based on recent shared ancestry, characterizing a monophyletic group, is called:
    1. homoplasy.
    2. parsimony.
    3. plesiomorphy.
    4. synapomorphy.
       
  5. Homology based on distant ancestry, associated with paraphyly:
    1. homoplasy.
    2. parsimony.
    3. plesiomorphy.
    4. synapomorphy..
       
  6. A taxonomic group which contains all of the species descended a common ancestor is described as:
    1. monophyletic.
    2. polyphyletic.
    3. paraphyletic.
       
       
  7. A taxonomic group which contains some but not all of the species descended from the most recent common ancestor of all the members of the group is described as:
    1. monophyletic.
    2. polyphyletic.
    3. paraphyletic.
       
  8. A taxonomic group which contains species descended from several different ancestors that are also ancestors of species classified into other groups is described as:
    1. monophyletic.
    2. polyphyletic.
    3. paraphyletic.
       
  9. In cladistic classification, all taxonomic groups should be:
    1. monophyletic.
    2. polyphyletic.
    3. paraphyletic.
       
  10. Attempts to deduce phylogenetic trees by comparing the similarities and differences among species are often confounded by numerous homoplasies.  The hypothesis that the "best" tree is that tree which requires the fewest homoplasies (occurrences of convergence, parallelism, or reversal) is called the principle of.
    1. cluster analysis.
    2. neighbor joining.
    3. bootstrapping.
    4. parsimony.
       
  11. In cladistic methods for deducing phylogenetic trees, each monophyletic group should be characterized by at least one:
    1. synapomorphy.
    2. plesiomorphy.
    3. homoplasy.
    4. parsimony.
    5. autopolyploidy.
       
  12. Processes of mutation and drift lead to the accumulation of molecular differences between reproductively isolated populations.  The (hypothetical) accumulation of such changes at statistically predictable rates is called the:
    1. meiotic drive.
    2. molecular clock.
    3. reaction norm.
    4. canalization of mutation.
       
  13. The molecular clock leads to an approximate correlation of sequence divergence with:
    1. homology.
    2. time since common ancestory.
    3. taxonomic rank.
    4. sequence complexity.
       
  14. Methods for deducing phylogenetic trees based on extent of molecular sequence divergence are called:
    1. phylogenetic methods.
    2. molecular methods.
    3. parsimony methods.
    4. distance methods.
       

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 13.  Correct answers are bold.

  1. Which lists shows the correct order from oldest to most recent?
    1. Cenozoic, Mesozoic, Paleozoic.
    2. Cenozoic, Paleozoic, Mesozoic.
    3. Mesozoic, Cenozoic, Paleozoic.
    4. Mesozoic, Paleozoic, Cenozoic..
    5. Paleozoic, Mesozoic, Cenozoic.
    6. Paleozoic, Cenozoic, Mesozoic..
       
  2. The Mesozoic Era began about:
    1. 930 mya.
    2. 570 mya.
    3. 250 mya.
    4. 150 mya.
    5. 65 mya.
       
  3. The Paleozoic Era began about:
    1. 930 mya.
    2. 570 mya.
    3. 250 mya.
    4. 150 mya.
    5. 65 mya.
     
  4. The Cenozoic Era began about:
    1. 930 mya.
    2. 570 mya.
    3. 250 mya.
    4. 150 mya.
    5. 65 mya.
       
  5. The root "cen-" (as in Cenozoic and Holocene) means:
    1. old.
    2. ancient.
    3. early.
    4. dawn.
    5. recent.
       
  6. Paleocene, Eocene, Oligocene, Miocene, Pliocene, and Pleistocene are all periods in which era?
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
       
  7. Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian are all periods in which era?
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
     
  8. Triassic, Jurassic, and Cretaceous are all periods in which era?
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
       
  9. The great Permian extinction occurred approximately:
    1. 930 mya.
    2. 570 mya.
    3. 250 mya.
    4. 150 mya.
    5. 65 mya.
       
  10. The great Cretaceous extinction occurred approximately:
    1. 930 mya.
    2. 570 mya.
    3. 250 mya.
    4. 150 mya.
    5. 65 mya.
       
  11. Tertiary is another name for:
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
         
  12. The "Age of Dinosaurs" is the:
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
       
  13. Dinosaurs died off at the end of the:
    1. Permian.
    2. Devonian.
    3. Jurassic.
    4. Cretaceous.
    5. Holocene.
       
  14. The "Age of Mammals" is the:
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
         
  15. Trilobites are characteristic fossils of the:
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
       
  16. Which lists shows the correct order from oldest to most recent?
    1. Miocene, Pliocene, Pleistocene, Oligocene.
    2. Miocene, Pliocene, Oligocene, Pleistocene.
    3. Miocene, Oligocene, Pliocene, Pleistocene.
    4. Oligocene, Pleistocene, Miocene, Pliocene.
    5. Oligocene, Miocene, Pliocene, Pleistocene.
       
  17. Which lists shows the correct order from oldest to most recent?
    1. Triassic, Jurassic, and Cretaceous.
    2. Triassic, Cretaceous, Jurassic.
    3. Jurassic, Triassic, Cretaceous.
    4. Jurassic, Cretaceous, Triassic.
    5. Cretaceous, Triassic, Jurassic.
       
  18. Which lists shows the correct order from oldest to most recent?
    1. Cambrian, Ordovician, Silurian, Devonian.
    2. Cambrian, Devonian, Silurian, Ordovician.
    3. Cambrian, Silurian, Ordovician, Devonian.
    4. Ordovician, Cambrian, Devonian, Silurian
    5. Ordovician, Silurian, Devonian, Cambrian.
       
  19. Which preceded the Paleocene?
    1. Eocene.
    2. Permian.
    3. Cretaceous.
    4. Devonian.
    5. Precambrian.
       
  20. Which preceded the Triassic?
    1. Eocene.
    2. Permian.
    3. Cretaceous.
    4. Devonian.
    5. Precambrian.
       
  21. Which preceded the Cambrian?
    1. Eocene.
    2. Permian.
    3. Cretaceous.
    4. Devonian.
    5. Precambrian.
       
  22. The relatively sudden and widespread appearance of fossils representing most extant phyla characterizes the:
    1. Permian / Triassic boundary.
    2. Cretaceous / Paleocene boundary.
    3. Ordovician / Silurian boundary.
    4. Precambrian / Cambrian boundary.
    5. Pleistocene / Holocene boundary.
       
  23. The most recent retreat of continental glaciers characterizes the:
    1. Permain / Triassic boundary.
    2. Cretaceous / Paleocene boundary.
    3. Ordovician / Silurian boundary.
    4. Precambrian / Cambrian boundary.
    5. Pleistocene / Holocene boundary.
       
  24. Fossil evidence of mammals first appears during the:
    1. Paleozoic.
    2. Mesozoic.
    3. Cenozoic.
       
  25. According to the hypothesis of punctuated equilibrium (as described in our text), most evolutionary change occurs:
    1. during speciation events.
    2. throughout species' the entire duration.
       
  26. According to the hypothesis of punctuated equilibrium (as described in our text), the duration of most species' existance, between speciation events, is marked by:
    1. sporadic change.
    2. continuous change.
    3. stasis.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 14.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 15.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 16.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

Study questions for Chapter 17.

Questions for Chapter 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17

304 index page

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Last updated:  9 May 2003 / dgk