Lesson 4.1.2

4.1.2 Measuring biodiversity: heterozygosity and diversity index Quiz: Pearson Edexcel Biology A (Salters-Nuffield), Unit 4

20 questions

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Lesson 4.1.2, Measuring biodiversity: heterozygosity and diversity index: 20 multiple choice questions for the Pearson Edexcel Biology A (Salters-Nuffield) (9BI0), Unit 4: Biodiversity and Natural Resources, written with Revision Ninja.

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The 20 questions

  1. What does the heterozygosity index H measure?

    • The number of species present in a habitat
    • The rate at which a population is growing each year
    • The proportion of individuals in a population that are heterozygous at a locus, indicating genetic diversity
    • The average length of the organisms in a population

  2. Which formula gives the heterozygosity index H?

    • H = number of homozygotes / number of heterozygotes
    • H = number of alleles / number of loci
    • H = number of heterozygotes / number of individuals in the population
    • H = number of individuals / number of species

  3. In a population of 40 individuals, 8 are heterozygous at a locus. What is H?

    • 0.2
    • 0.02
    • 0.4
    • 5

  4. A population has 50 individuals, and 15 are heterozygous at a locus. What is the heterozygosity index H?

    • 0.3
    • 0.5
    • 0.15
    • 0.7

  5. What is the value of H if every individual in a population is homozygous?

    • 1
    • 2
    • 0
    • 0.5

  6. Which formula is used to calculate the index of diversity D in a habitat?

    • D = sum of n / N
    • D = N(N - 1) / sum of n(n - 1)
    • D = N / sum of n
    • D = sum of n(n - 1) / N(N - 1)

  7. In a sample of 20 individuals from three species with counts 10, 6 and 4, what is the index of diversity D?

    • 5.5
    • 0.35
    • 20
    • 2.88

  8. Which habitat has the higher index of diversity D, if it contains many species each with few individuals?

    • The habitat dominated by one species, because it has fewer species
    • The habitat with many species evenly represented
    • The habitat with the fewest individuals in total
    • Both habitats must have the same value of D

  9. Why is a value of H equal to 0.5 more informative than a count of heterozygotes alone?

    • It gives the proportion of the population that is heterozygous, allowing comparison between populations of different size
    • It shows the age structure of the population
    • It shows the number of genes in the genome
    • It shows the total number of species in the area

  10. Which statement about measuring biodiversity is correct?

    • Species richness can only be measured using genetic methods
    • Species richness and heterozygosity measure exactly the same quantity
    • Species richness measures the number of species
    • Heterozygosity counts the number of different habitats in an area

  11. A sample of 10 individuals contains 4 heterozygotes at a locus. What percentage of the sample is heterozygous?

    • 10%
    • 4%
    • 0.4%
    • 40%

  12. A habitat has a total of N = 10 individuals from two species, with counts of 8 and 2. What is D?

    • 10
    • 1.55
    • 20
    • 2.5

  13. Which measurement would best show genetic diversity within a single species?

    • Area of the sampled quadrat
    • Number of habitats in the region
    • Index of diversity D based on species counts
    • Heterozygosity index H

  14. Which of these is a limitation of using only species richness to compare habitats?

    • It cannot be counted in any habitat
    • It requires genetic sequencing for every species
    • It ignores how many individuals each species has
    • It ignores the number of species present

  15. A population of 200 individuals has 30 heterozygotes at a locus. What is H expressed as a decimal?

    • 0.6
    • 6.7
    • 0.3
    • 0.15

  16. Why does a large value of H indicate a population with greater genetic diversity?

    • The population is smaller and therefore more inbred
    • More individuals carry different alleles at the locus, so there is more variation
    • More individuals are homozygous for the same allele
    • The population has fewer alleles in total

  17. What does a low value of D indicate about a habitat?

    • A habitat with no living organisms at all
    • A habitat that has just been colonised by new species
    • High diversity, with many species evenly represented
    • Low diversity, with few species or most individuals belonging to one or a few species

  18. Which conclusion can be drawn from a higher D value in habitat A than in habitat B?

    • Habitat A contains more individuals than habitat B
    • Habitat A has a higher genetic diversity within each species
    • Habitat A is more diverse than habitat B, given the same sampling effort
    • Habitat B must have been polluted

  19. Why is the heterozygosity index calculated from heterozygotes rather than from all individuals?

    • Heterozygotes always outnumber homozygotes in a natural population
    • Heterozygotes carry two different alleles
    • Heterozygotes indicate the age structure of the population
    • Heterozygotes are easier to count than homozygotes in every field sample

  20. In a sample of 25 individuals, 5 are heterozygous at a locus. What is H?

    • 5
    • 0.05
    • 0.2
    • 0.5

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