Classification of Living Organisms (AQA GCSE Biology: Combined Science)

Exam Questions

1 hour10 questions
1a4 marks

Complete the sentence using the correct words from the box below.

You will not need to use every word from the box. 

A species is a group of similar _____________ that belong to the classification group below ___________. They can ____________ naturally with one another and produce _____________ offspring. 

animals          reproduce          living          phylum

genus          organisms          fertile          mix



1b1 mark

Figure 1 shows a bald eagle, an iconic species in North America.

Figure 1

bald-eagle-1

Which of A - D shows the correct way to write the bald eagle's binomial name? 

  • haliaeetus leucocephalus

  • Haliaeetus leucocephalus

  • haliaeetus leucocephalus

  • Haliaeetus leucocephalus

1c1 mark

Seven levels of classification of organisms are shown in Table 1, in descending order of size.

Two of the group names have been placed in the wrong sequence.

Identify which two. 

Table 1

Kingdom
Phylum
Class
Family
Order
Genus
Species

1d1 mark

Name the biologist who gave his name to the system of classification referred to in Question 1c). 

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2a1 mark

Which scientist first devised and set up the three-domain system of classification of organisms? 

  • Carl Woese

  • Carl Linnaeus

  • Charles Darwin

  • Gregor Mendel

2b3 marks

Name the three domains of the three-domain system of biological classification. 

2c3 marks

Figure 2 shows the three domains referred to in Question 2b), along with a number of descriptions which apply to each of the three domains.

Figure 2

3-d-1

Using a straight line, draw one line from each domain to the description that is unique to it. 

2d2 marks

Which of these two statements is correct?

  1. All eukaryotes are multicellular organisms.
  2. All multicellular organisms are eukaryotes.

Explain your answer.

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3a1 mark

Diagrams A - D below show four species, W, X, Y and Z in an evolutionary tree. 

phylo-tree-mcq-1

In which of A - D is species Y most closely related to species Z?

    3b3 marks

    Figure 3 shows an evolutionary tree for a number of plant groups. 

    Figure 3

    phylogenetic-diagram-1

    Complete the sentence using the correct words from the box.

    The green algae in Figure 3 represents the __________________ of all the plant groups shown. The liverwort's least closely related group is the ______________. A common feature among all the groups shown is the ability to perform ______________.

    hornworts               common ancestor          nearest descendent

    angiosperms               sexual reproduction           photosynthesis

    3c2 marks

    Of the plant groups shown in Figure 3 in Question 3b), the angiosperms are a wide group of plants that produce flowers and fruit. 

    Aside from differences in appearance to the naked eye, name two techniques that scientists can use to classify plant species within the angiosperm group. 

    3d2 marks

    Figure 4 shows an adult and infant capybara, the largest species of rodent in the world. 

    Figure 4

    capybara-1

    The capybara belongs to the following classification groups, in descending order of size. 

    1. Eukaryotes
    2. Animals
    3. Chordates
    4. Mammals
    5. Rodents
    6. Caviidae
    7. Hydrochoerus
    8. hydrochaeris

    Name the family and the class that the capybara belongs to.

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    1a2 marks

    The King Penguin and Emperor Penguin are two species of penguin.

    Collectively they are known as “the great penguins”.

    Define the term species.

    1b2 marks

    Table 1 below shows part of the classification of both species.

    Table 1

    Classification group King Penguin Emperor Penguin
      Animalia Animalia
      Chordata Chordata
    Class Aves Aves
      Sphenisciformes Sphenisciformes
    Family Spheniscidae Spheniscidae
      Aptenodytes Aptenodytes
    Species patagonicus forsteri

    Some of the classification groups are missing from the table above.

    Complete the table.

    1c1 mark

    Give the binomial name of the Emperor Penguin.

    1d2 marks

    Suggest a reason why the binomial naming system is a useful way of helping scientists classify organisms.

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    2a1 mark

    A group of students were investigating fruit flies for a school project.

    Fruit flies belong to the classification kingdom ‘Animalia’.

    What type of cells are found in a fruit fly?

    2b3 marks

    The way that scientists classify organisms has changed over time.

    In the 1970’s Carl Woese developed a classification system called the ‘three-domain system’.

    Name the three domains.

    2c3 marks

    Name which domain fruit flies belong to in the three-domain system. Justify your answer.

    2d3 marks

    The students collected three different types of fruit fly to study.

    The three species of fruit fly were Ceratitis capitata, Dacus dorsalis and Dacus oleae.

    What do these names suggest about the evolutionary relationships between these fruit fly species?

    Explain your answer.

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    3a1 mark

    In 1753, the Swedish botanist Carl Linnaeus published his book Species Plantarum.

    Every known species of plant known at the time was listed in this book.

    The plants were classified into groups called genera and each individual species was given a binomial name.

    Name the two classification groups that are identifiable in a binomial name.

    3b6 marks

    Scientists have been classifying organisms into groups for centuries.

    Modern technological developments have enhanced the ability of scientists to classify organisms into groups and to understand the evolutionary relationships between them.

    Describe how the process of classifying organisms has changed over time.

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    4a1 mark

    Figure 1 shows part of the evolutionary tree for penguins.

    Figure 1

    ehgU9mNq_1

    What does the evolutionary tree in Figure 1 tell us about the evolution of the Emperor and King penguins in relation to other species of penguin?

    4b2 marks

    What evidence is used by scientists to build an evolutionary tree to show the relatedness of organisms?

    4c2 marks

    Suggest why scientists view evolutionary trees as “a hypothesis of the evolutionary past”.

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    5a1 mark

    Evolutionary trees are a method to show how scientists believe organisms are related.

    Part of the evolutionary tree for the Canidae family, which includes the domestic dog, is shown in Figure 2 below.

    Figure 2-G6druvZ_2

    Draw a line and mark an ‘X’ on Figure 2 to show where the last common ancestor for the species’ Canis latrans and Canis lupus is.

    5b3 marks

    In the evolutionary tree shown in Figure 2, the domestic dog has the same binomial name as the gray wolf, but has been given an additional subspecies name, familiaris.

    Suggest why domestic dogs might be classified in this way.

    5c4 marks

    Five million years of evolution is represented by the evolutionary tree in Figure 2.

    Explain how several different species of canine could have evolved from a common ancestor over 5 million years.

    5d2 marks

    Scientists use molecular data and DNA analysis to develop evolutionary trees such as those shown in Figure 2.

    The enzymes involved in aerobic respiration can be studied to determine the relationships between different members of the canine family.

    Explain how DNA sequencing of an enzyme involved in aerobic respiration could have been used to determine the relationship between the domestic dog, grey wolf and coyote.

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    1a3 marks

    When attempting to classify organisms based on their characteristics, several types of difference between organisms can be observed. These are shown in Table 1.

    Table 1

    Differences Description
    A Differences observable under a microscope
    B Anatomical differences
    C Differences in DNA base sequences
    D Morphological differences
    E Differences in amino acid sequences

    Complete the table below to reorder differences A - E into the order of the amount of detail that can be gained, starting with the least detailed.  

    1st 2nd 3rd 4th 5th
             

    1b2 marks

    When carrying out DNA comparisons between species, explain why the same gene has to be selected from each species for sequencing. 

    1c4 marks

    Table 1 gives information about the amino acids that go into the chain of haemoglobin found in the blood of various animal species. The second column shows how many amino acids are different in the haemoglobin of that species to that of humans. 

    Table 1

    Animal Number of amino acids different to human haemoglobin
    Human 0
    Chicken 45
    Dog 15
    Frog 67
    Gibbon 2
    Gorilla 1
    Grey kangaroo 38
    Horse 25
    Mouse 27

    Based on your knowledge of classification and on the data in Table 1, draw a labelled evolutionary tree for the animals listed. 

    1d
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    3 marks

    This question refers to the data in Table 1.

    Humans and gibbons evolved separately from a common ancestor about 18 million years ago.

    Calculate an estimate of how many years ago the evolution of frogs diverged from that of humans. 

    Give your answer in standard form. 

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    2a2 marks

    The system of classification of organisms devised by Carl Linnaeus can be described as follows:

    A hierarchical classification system of organisms in biology that is used to organise and group similar organisms together so that they can be more easily understood. A hierarchical system is one in which larger groups contain smaller groups with no overlap between groups.

    Explain why it is important for there to be no overlap between groups. 

    2b4 marks

    Observers looking at the Linnaean hierarchy of organisms could criticise the system as just being one that sorts organisms into convenient groups with no apparent scientific benefit. 

    On the other hand, evolutionists would disagree strongly with that point of view.

    Suggest the benefits to evolutionists (and to biology in general) of classifying organisms in a hierarchical system like the Linnaean system. 

    2c2 marks

    Scientists investigating extinct species have used the fossil record to piece together evolutionary timelines for those organisms. 

    On occasions, the bodies of well-preserved animals are discovered, such as the woolly mammoth, Yuka, found in ice in Siberia in 2012. 

    Suggest the possible benefits of having a well-preserved animal carcass to examine, as opposed to fossils alone. 

    2d2 marks

    Explain why, in evolutionary terms, the more recent a common ancestor between two species, the more closely related those two species are. 

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