Population Genetics and Evolution Practice Problems

By — McGraw-Hill Professional
Updated on Aug 23, 2011

Review the following concepts if needed:


Vocabulary   For each of the following definitions, give the appropriate term and spell it correctly. Terms are single words unless indicated otherwise.

  1. The breeding structure of a population when each gamete has an equal opportunity of uniting with any other gamete from the opposite sex. (One or two words.)
  2. The total genetic information possessed by the reproductive members of a population of sexually reproducing organisms. (Two words.)
  3. An important model of population genetics. (Three words.)
  4. The condition of a locus that does not experience a change in allelic frequencies from one generation to the next.
  5. An interbreeding group of organisms sharing a common gene pool. (Two words.)
  6. Changes in gene frequencies due to sampling errors in very small populations. (Two words.)
  7. A deviation from Hardy-Weinberg expectations at any specific time in a population.
  8. A phenotypically and/or geographically distinctive group, composed of individuals inhabiting a defined geographic and/or ecological region, and possessing characteristic phenotypic and gene frequencies that distinguish it from other such groups.
  9. The general hallmark criterion that demarcates one biological species from another. (Two words.)
  10. Any change in the genetic composition of a population, such as a change in allele frequency.

Multiple-Choice Questions   Choose the one best answer.

For problems 1–4, use the following information. Snapdragon flowers may be red (CrCr), pink (CrCW), or white (CWCW). A sample from a population of these plants contained 80 white, 100 pink, and 20 red-flowered plants.

  1. The frequency of the red allele (Cr ) in this sample is   (a) 0.10   (b) 0.20   (c) 0.30   (d) 0.45   (e) none of the above
  2. The percentage of pink-flowered plants expected on the basis of the Hardy-Weinberg equation is approximately   (a) 35   (b) 45   (c) 50   (d) 55   (e) none of the above
  3. A chi-square test of the sample data against the Hardy-Weinberg expectations produces a chi-square value of   (a) 1.96   (b) 2.43   (c) 2.87   (d) 3.02   (e) 3.11
  4. Refer to Table 2-3 to answer this question. Assuming the sample is representative of its population in problem 3 above, it may be said that   (a) the chi-square test is significant and the sampled population is not in genetic equilibrium,   (b) the chi-square test is nonsignificant and the sampled population is not in genetic equilibrium   (c) the chi-square test is significant and the sampled population is in genetic equilibrium   (d) the chi-square test is nonsignificant and the sampled population is in genetic equilibrium   (e) the chi-square value is significant, thereby invalidating the test.

For problems 5–7, use the following information. Black pelage is an autosomal dominant trait in guinea pigs; white is the alternative recessive trait.AHardy-Weinberg population was sampled and found to contain 336 black and 64white individuals.

  1. The frequency of the dominant black gene is estimated to be   (a) 0.60   (b) 0.81   (c) 0.50   (d) 0.89   (e) none of the above
  2. The percentage of black individuals that is expected to be heterozygous is approximately   (a) 46   (b) 57   (c) 49   (d) 53   (e) none of the above
  3. The probability that a black male crossed to a white female would produce a white offspring is approximately   (a) 0.12   (b) 0.14   (c) 0.16   (d) 0.18   (e) none of the above

For problems 8–10, use the following information. Yellow body color in Drosophila is governed by a sex-linked recessive gene; wild-type color is produced by its dominant allele.

  1. A sample from a Hardy-Weinberg population contained 1021 wild-type males, 997 wild-type females, and 3 yellow males. The percentage of the gene pool represented by the yellow allele is estimated to be   (a) 0.04   (b) 0.16   (c) 0.21   (d) 0.42   (e) none of the above
  2. If the frequency of the yellow allele is 0.01, the percentage of wild-type females expected to carry the yellow allele is   (a) 1.98   (b) 1.67   (c) 2.04   (d) 2.76   (e) none of the above
  3. If the frequency of the yellow allele is 1.0 in females and 0 in males, the frequency of that allele in males of the next generation is expected to be   (a) 1.0   (b) 0.5   (c) 0.33   (d) 0.67   (e) none of the above



  1. random mating or panmixis
  2. gene pool
  3. Hardy-Weinberg rule
  4. equilibrium
  5. Mendelian population
  6. genetic drift
  7. disequilibrium
  8. race or subspecies
  9. reproductive isolation
  10. evolution

Multiple-Choice Questions

  1. e(035)
  2. b(455%)
  3. a
  4. d
  5. a
  6. b
  7. e(0286)
  8. e(029)
  9. a
  10. a
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