Classification & Biodiversity — Drills · Grade 10 Science

Chapter: Evolution, Ancestry & Biodiversity

What these drills covers

By the end of Classification & Biodiversity you should be able to:

6 questions, multiple choice, numeric and written answer, each with a worked explanation.

Vocabulary used: taxonomy, binomial nomenclature, domain, cladogram, shared derived trait, biodiversity.

Problem 1

In the classification hierarchy, which grouping contains the fewest kinds of organism?
  1. Domain
  2. Kingdom
  3. Genus
  4. Species
Answer and explanation

Species

The hierarchy runs from broad to narrow — domain, kingdom, phylum, class, order, family, genus, species — so species is the narrowest.

Problem 2

In the binomial name Canis lupus, the word Canis is the
  1. species
  2. genus
  3. family
  4. domain
Answer and explanation

genus

The first word is the genus and the second identifies the species within it; the convention gives every species a unique two-part name.

Problem 3

Community A contains 14 species and community B contains 9. How many more species does A contain?
Answer and explanation

5

14 − 9 = 5 more species, which is a difference in species richness.

Problem 4

A sample of 200 individuals contains 180 of one species and 20 of a second. What percentage belongs to the most common species?
Answer and explanation

90 %

180 / 200 × 100 = 90 percent, which shows low evenness: richness of 2 does not mean the two species are equally represented.

Problem 5

Explain why classifications are revised when new evidence appears, using molecular data as the example.
Answer and explanation

Classification aims to reflect evolutionary relationships, so it depends on the evidence available about those relationships. Earlier schemes relied largely on visible structure, which can mislead because similar forms arise independently. Molecular comparison provides evidence that does not depend on form, and when sequences show that a group defined by appearance contains species with different ancestries, the group is redefined. Revision is therefore a sign that classification is evidence-based rather than a sign of earlier carelessness.

Response criteria

  • State a biologically accurate conclusion.
  • Show the data, mechanism, or calculation that supports it.
  • Include units, conditions, or limits where relevant.

Problem 6

Two communities each contain 10 species. Explain why they may still differ in biodiversity.
Answer and explanation

Species richness counts how many species are present, but biodiversity also depends on evenness — how individuals are distributed among those species. A community with ten species in roughly equal numbers is more diverse than one where a single species holds 95 percent of the individuals and the other nine are rare, because the second is dominated by one species and its rare ones are vulnerable to loss. Richness alone therefore gives an incomplete comparison.

Response criteria

  • State a biologically accurate conclusion.
  • Show the data, mechanism, or calculation that supports it.
  • Include units, conditions, or limits where relevant.

Browse all courses