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Exam questions · Biology · Evidence for Evolution and Classification

Classification and the Linnaean System

  • 7 exam questions
  • 21 marks
  • 8 quick checks
  1. 1 Name [2 marks]

    Name the smallest and the largest groups in the Linnaean system of classification.

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    Model answer

    The smallest group is the species. The largest group is the kingdom.

    Mark scheme

    • Species is the smallest — 1 mark
    • Kingdom is the largest — 1 mark
  2. 2 Give [3 marks]

    Write the seven ranks of the Linnaean system in order, starting with the largest group.

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    Model answer

    Kingdom, phylum, class, order, family, genus, species.

    Mark scheme

    • Kingdom, phylum, class in order — 1 mark
    • Order and family in order — 1 mark
    • Genus and species in the right order — 1 mark
  3. 3 Explain [3 marks]

    The diagram shows the classification of humans. Explain how the binomial name for humans is made up, and why the bars get narrower.

    Seven stacked bars showing the classification of humans.
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    Model answer

    The binomial name has two parts, the genus followed by the species, so it is Homo sapiens. The bars get narrower because each group is divided into smaller groups, so there are fewer organisms in each rank down, and they have more characteristics in common.

    Mark scheme

    • Genus followed by species — 1 mark
    • Homo sapiens — 1 mark
    • Each rank has fewer organisms, which are more alike — 1 mark
  4. 4 Explain [3 marks]

    The classification of four mammals is shown. Mammal W: Panthera leo. Mammal X: Panthera tigris. Mammal Y: Felis catus. Mammal Z: Canis lupus. Which two mammals are most closely related? Explain your answer.

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    Model answer

    Mammals W and X are most closely related. They are in the same genus, Panthera, which means that they share more ranks than any other pair. Y is in a different genus of the same family, and Z is in a different family.

    Mark scheme

    • W and X — 1 mark
    • Same genus (Panthera) — 1 mark
    • They share more groups than other pairs — 1 mark
  5. 5 Describe [3 marks]

    Describe how organisms are named using the binomial system.

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    Model answer

    Each organism has a name of two parts. The first part is the genus, written with a capital letter, and the second part is the species, written with a lower case letter. The name is written in italics, or underlined if handwritten.

    Mark scheme

    • Two names — 1 mark
    • Genus then species — 1 mark
    • Capital letter for the genus and lower case for the species — 1 mark
  6. 6 Explain [3 marks]

    Explain why scientists use scientific names for organisms rather than common names.

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    Model answer

    Common names are different in different countries and languages. The same common name may be used for more than one species. A scientific name is the same everywhere and identifies only one species.

    Mark scheme

    • Common names vary between countries — 1 mark
    • A common name may refer to more than one species — 1 mark
    • A scientific name is the same everywhere — 1 mark
  7. 7 Evaluate [4 marks]

    Evaluate the Linnaean system of classification as a way of showing how closely organisms are related.

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    Model answer

    The system is useful because organisms in the same group share structures and characteristics, and the lower the rank they share, the more closely they are related. It is standard and used worldwide. However, it is based on structure, so organisms that look similar may be grouped together even if they are not closely related, and it cannot show how recently species diverged. New evidence has led to changes.

    Mark scheme

    • Groups organisms by shared characteristics — 1 mark
    • Standard and used worldwide — 1 mark
    • Based on structure, so may not show true ancestry — 1 mark
    • Has been changed by new evidence — 1 mark

Quick check

  1. 1

    Who developed the system of classification into kingdom, phylum, class, order, family, genus and species?

    1. ACharles Darwin
    2. BGregor Mendel
    3. CCarl Linnaeus
    4. DAlfred Wallace
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    C: Carl Linnaeus

    Carl Linnaeus developed the system.

  2. 2

    Which is the smallest group in the Linnaean system?

    1. AGenus
    2. BSpecies
    3. CFamily
    4. DOrder
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    B: Species

    The species is the smallest group.

  3. 3

    Which is the correct order of ranks from largest to smallest?

    1. AKingdom, class, phylum, order, family, genus, species
    2. BKingdom, phylum, order, class, family, genus, species
    3. CKingdom, phylum, class, family, order, genus, species
    4. DKingdom, phylum, class, order, family, genus, species
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    D: Kingdom, phylum, class, order, family, genus, species

    Kingdom, phylum, class, order, family, genus, species.

  4. 4

    What does the binomial system use to name an organism?

    1. AIts genus and species
    2. BIts kingdom and phylum
    3. CIts family and order
    4. DIts common name and age
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    A: Its genus and species

    Binomial means two names: the genus and the species.

  5. 5

    Which is the correct way to write the scientific name of humans?

    1. Ahomo sapiens
    2. BHomo Sapiens
    3. CHomo sapiens
    4. DHOMO sapiens
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    C: Homo sapiens

    The genus has a capital letter and the species has a lower case letter: Homo sapiens.

  6. 6

    Two organisms are in the same genus. What does this show?

    1. AThey are the same species
    2. BThey are very closely related
    3. CThey are in different kingdoms
    4. DThey cannot breed with anything
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    B: They are very closely related

    Organisms in the same genus are very closely related.

  7. 7

    What is the Linnaean system mainly based on?

    1. ATheir DNA only
    2. BTheir habitat only
    3. CTheir age
    4. DTheir structure and characteristics
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    D: Their structure and characteristics

    Traditionally organisms were grouped by their structure and characteristics.

  8. 8

    Why is a scientific name better than a common name?

    1. AIt is the same everywhere and names one species
    2. BIt is shorter
    3. CIt is easier to spell
    4. DIt has been used for fewer years
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    A: It is the same everywhere and names one species

    It is the same all over the world and refers to one species.