Genetics Quiz 2

Genetics Quiz

Genetics Quiz #2

Mendel’s Laws: 2. Principle of Independent Assortment: Genes for different traits assort independently of one another in gamete production What it means: different genes are inherited separately. For example, the gene which codes for eye color is inherited separately from the gene which codes for nose shape.

31. A ___________ trait is one that has been inherited from an earlier ancestor.

  • A) neutral
  • B) homologous
  • C) primitive
  • D) derived
ANS: {C} primitive


32. A _________ trait is one that has changed from an ancestral state.

  • A) neutral
  • B) homologous
  • C) primitive
  • D) derived
ANS: {D} derived


33. Neither apes nor humans have a tail, whereas other primates have tails. Compared with apes, the lack of a tail in human beings is a _____________ trait since they both inherited it from a
common ancestor.

  • A) neutral
  • B) homologous
  • C) primitive
  • D) derived
ANS: {C} primitive


34. ________ is used to determine what traits are primitive and what traits are derived in an analysis of closely related species.

  • A) A molecular clock
  • B) An outgroup
  • C) A phenetic approach
  • D) An adaptive radiation model
ANS: {B} An outgroup


35. Imagine you are studying the presence and absence of a hairy nose in a hypothetical group of organisms. If your outgroup shows a hairy nose, this means that a hairy nose is a __________ trait.

  • A) primitive
  • B) derived.
ANS: {A}  primitive


36. If you classify organisms based on all homologous traits, you are using a(n) __________ approach.

  • A) population genetic
  • B) homologous
  • C) evolutionary systematics
  • D) cladistic
ANS: {C}  evolutionary systematics

37. If you classify organisms based on evolutionary relationships, you are using a(n) ___________ approach.

  • A) population genetic
  • B) homologous
  • C) evolutionary systematics
  • D) cladistic
ANS: {D} cladistic


38. Cladistics is a method of classification that considers

  • A) traits that show homology and homoplasy.
  • B) all homologous traits, both primitive and derived.
  • C) only primitive homologous traits.
  • D) only derived homologous traits.
ANS: {D} only derived homologous traits.


39. According to the method of cladistics, two species are placed in the same group if they share__________ traits.

  • A) any homologous
  • B) primitive
  • C) derived
  • D) polymorphic
ANS: {C}  derived


40. If parallel evolution is common, the evolutionary systematics approach to classification will

  • A) make species seem more distantly related than they really are.
  • B) make species seem more closely related than they really are.
  • C) have no effect on judging evolutionary relationships.
  • D) make it seem as though there were more species than actually existed.
ANS: {B} makes species seem more closely related than they really are.


41. A population is a group of individuals of a species which:

  • A) interbreed.
  • B) reside in the same area.
  • C) inhabit the same space at the same time.
  • D) only b and c are true
  • E) a, b, and c are true
Ans: {E}  a, b, and c are true


42. The sum total of all alleles carried in all members of a population is called its:

  • A) gene pool.
  • B) genome.
  • C) ploidy.
  • D) polygenic sum.
  • E) polymorphism.
Ans: {A} gene pool.

43. Microevolution is defined as:

  • A) a process that includes new species formation.
  • B) changes in the frequency of alleles within a population.
  • C) evolution of microorganisms.
  • D) interactions between species.
  • E) all of the above
Ans: {B}  changes in the frequency of alleles within a population.


44. Macroevolution is defined as:

  • A) evolution that occurs over geologic time.
  • B) process by which new species emerge from existing species.
  • C) the consequence of extended periods of microevolution.
  • D) the origin of new species by mutation and natural selection.
  • E) all of the above
Ans: {E} all of the above


45. Population genetics provides answers for all of the following questions except:

  • A) what is the frequency of genetic disease in a population?
  • B) what fraction of the phenotypic variation in a trait is the result of genetic variation?
  • C) what alleles are most likely to mutate?
  • D) given certain quantifiable variables, how long is a disease likely to persist?
  • E) how rapidly can a disease gain a foothold in a population?
Ans: {C} what alleles are most likely to mutate?


46. Which of the following is not one of the assumptions of the Hardy-Weinberg law ?

  • A) The population is very large.
  • B) There is non-random mating within the population.
  • C) Mutations in the alleles do not occur.
  • D) No migration occurs into or out of the population.
  • E) The ability of all genotypes for survival and reproduction is the same.
Ans: {B} There is non-random mating within the population.


47. Hardy-Weinberg equilibrium in populations is defined as conditions that produce:

  • A) only heterozygotes.
  • B) many lethal alleles.
  • C) genetic drift.
  • D) constant allele frequencies which do not change from generation to generation.
  • E) all of the above
Ans: {D} constant allele frequencies which do not change from generation to generation.


48. The heterozygote genotype frequency term for a gene with two alternate alleles A (frequency p) and a (frequency q) in the Hardy-Weinberg equation is:

  • A) p 2
  • B) q 2
  • C) 2pq.
  • D) (p+q)2
  • E) p+q.
Ans: {C}  2pq.

49. If in a population of 1 million people, 100 albinos (homozygous recessives, aa) were found, how many normal (homozygous dominants, AA) individuals will be found in the next generation under equilibrium conditions?

  • A) 19,800
  • B) 100,000
  • C) 980,010
  • D) 999,900
  • E) 100
Ans: {C}  980,010


50. In humans, brachydactyly is a dominant condition. Six thousand four hundred people in a population of 10,000 show the disease (1,600 are BB, 4,800 are Bb) and 3,600 are normal phenotypes (bb). The frequency of the b allele is:

  • A) 0.6.
  • B) 0.4.
  • C) 0.36.
  • D) 0.48.
  • E) 0.16.
Ans: {A}  0.6.


51. The frequency of the Hemoglobin A allele is 0.9. The heterozygote with the recessive allele, s, show resistance to the malarial parasite. What is the frequency of the heterozygote for the pair As?

  • A) 0.81
  • B) 0.1
  • C) 0.01
  • D) 0.18
  • E) 0.09
Ans: {D} 0.18


52. The genotypic frequency of inherited autosomal recessive condition, phenylketonuria, is 1 in 3,600 people. The frequency of the normal allele is:

  • A) 0.0167.
  • B) 0.9833.
  • C) 0.0328.
  • D) 0.00286.
  • E) 3,599.
Ans: {B} 0.9833.


53. Which of the following is not generally true about conditions of natural populations?

  • A) Size is not always very large.
  • B) Individuals do not mate at random.
  • C) New mutations do occur.
  • D) There is migration in and out of the population.
  • E) Different genotypes have the same fitness.
Ans: {E} Different genotypes have the same fitness.

54. Fitness is described as:

  • A) an individual's ability to survive to adulthood.
  • B) an individual's ability to reproduce.
  • C) the effect of the particular genotype which cannot always be predicted.
  • D) a, b, and c are true.
  • E) only a, and b are true.
Ans: {D} a, b, and c are true.


55. Changes in allele frequency in conditions of either natural or artificial selection depends on:

  • A) allele frequencies themselves.
  • B) relative fitness related to viability.
  • C) reproductive abilities of the different phenotypes.
  • D) a, and b only.
  • E) a, b, and c.
Ans: {D} a, and b only.


56. Many human recessive genetic diseases are maintained despite continuing selection against them because:

  • A) heterozygotes have higher fitness than either homozygote.
  • B) the recessive alleles mutate to the dominant type.
  • C) there is no inheritance for the recessive allele.
  • D) the dominant allele frequency remains the same over generations.
  • E) none of the above.
Ans: {A} heterozygotes have higher fitness than either homozygote.


57. A disease that has been studied in great detail for heterozygote superiority is:

  • A) brachydactyly.
  • B) sickle cell disease.
  • C) insulin-dependent diabetes.
  • D) albinism.
  • E) tuberculosis.
Ans: {B} sickle cell disease.


58. If African populations have a relative fitness of the wild type genotype of 0.8, and that of the heterozygote of 1.0, then the relative advantage in the fitness of the heterozygotes would be:

  • A) 0.8.
  • B) 0.08.
  • C) 0.16.
  • D) 0.28.
  • E) 1.25.
Ans: {E} 1.25.


59. Mutations arise from:

  • A) DNA damage due to environmental agents.
  • B) from errors in replication.
  • C) from errors in the transmission of genetic information in cell division.
  • D) only a and b.
  • E) a, b, and c.
Ans: {E} a, b, and c.

60. The frequency of disease alleles is influenced by:

  • A) heterozygous advantage.
  • B) mutation.
  • C) time of onset of disease.
  • D) selection.
  • E) all of the above.
Ans: {E} all of the above.