Lesson 1.6 Classifying animals

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Introduction to the lesson

You have now discovered the five kingdoms that all living organisms are divided into. In this and the next lesson you will look in more detail at some of the major groups into which the animal kingdom is classified. In today’s lesson you will look at the five classes that fall under the Phylum Vertebrates. It is a fairly long lesson, so you may want to take two or even three days to complete it, but most of the activities should be simply a revision of prior knowledge.

Review of past lessons

Before you begin the lesson, review

  • Review the seven characteristics of living organisms. (Lesson 1.2). Consider how these apply to animals.
  • Review the categories of classification from kingdom to species (Lesson 1.3)
  • Review characteristics of all animals (Lesson 1.4).
  • Review the definitions from Lessons 1.2 to 1.5.

Preparing for the lesson

  1. When you hear the word “animal”, what do you understand by the word? What animal (or group of animals) do you think of? Do you think of a mammal when you hear the word “animal”? If you did, then you part of the majority group – most people think of a mammal when they hear the word “animal”. Can you think of a possible reason?
  2. Give some examples of animals you know that are NOT mammals?
  3. Can you think of some animals that live in water? (Which mammal lives in the sea?)
  4. Can you think of some animals, besides birds that fly?
  5. Which bird(s) can’t fly?
  6. Which is the largest class of animals? Which is the largest group within that class?
  7. Which is YOUR favorite animal and why?

Classifying animals

Look at Figure 1.10 on p. 9 of the course book. This diagram shows some of the major groups into which the animal kingdom is classified.

Learning Activity 1

Using Figure 1.10 and your own knowledge, answer the following questions in your exercise book:

  1.  Name the five phylum mentioned in the figure. (Look back to lesson 2 to see where phylum fits into the classification order)
  2.  Which phylum(s) has (have) animals with a backbone?
  3. Which phylum(s) has (have) animals with no backbone?
  4. What is a class? (refer back to Lesson 2)
  5. How many classes are there in the phylum vertebrates? Name them.
  6. The figure gives one class under the phylum arthropods (class insects), can you name at least another three classes under the phylum arthropods?

Phylum Vertebrates

Read the section 'Phylum Vertebrates' from p. 9-10

The IG biology course assumes a prior knowledge of the different classes of vertebrates. The learning activities that follow will encourage you to remember what you have learned in previous years. You may need to consult other resources such as books or the internet, to answer these questions.

Learning Activity 2: Class Fish

  1. What is the main habitat of the class of fish?
  2. How do fish breathe under water?
  3. Why is the streamline shape of the fish important for movement?
  4. What is the purpose of the fish’s fins?
  5. What function do the scales have?
  6. What are the two main groups of fish?
  7. What is the purpose of the swim bladder?

Learning Activity 3: Class Amphibians

  1. Describe the life-cycle of a frog.
  2. What two habitats do amphibians spend part of their life cycle in?
  3. What anatomical changes must occur in an amphibian to allow it to live in these two habitats?
  4. Describe an amphibian’s skin.
  5. Name some amphibians.

Learning Activity 4: Class Reptiles

  1. Describe the life cycle of a reptile.
  2. Describe the eggs of a reptile and state why they do not need to be laid in water.
  3. Briefly describe the type of food various reptiles eat and how they are able to eat that type of food. (Think about a tortoise and what it eats and why it does not need teeth, compared to the crocodile and its teeth and how it kills its prey and then compare that to a snake.)
  4. Reptiles are cold-blooded. What does this mean and does it affect their behaviour?
  5. Name some reptiles

Learning Activity 5: Class Birds

  1. Describe the avian egg.
  2. Describe some of the adaptions birds have made to enable them to fly.
  3. Name and briefly describe the different types of feathers found on a bird.
  4. Briefly describe what birds eat and what shape of beak is best suited to what food type.

Learning Activity 6: Class Mammals

  1. Humans are classified as belonging to the class of mammals.
    1. Why do you think they belong to this class?
    2. List some differences between humans and other mammals?
  2. What is different between mammal reproduction and that of the other classes of vertebrates?
  3. Mammals are endothermic. What does this mean?
    1. What is the normal body temperature of a human being?

Learning Activity 7

Make yourself a chart similar to figure 1.10 but where you can add the details of each of the phylum and the classes under the phylum.

  1. Under Phylum Vertebrates, list the characteristics of the phylum.
  2. Make a section for each of the classes and give the characteristics of each class.
  3. Draw a representative animal for each class (similar to Figures 1.11-1.15) and label your drawing. You may add extra labels not included in the course book.

Keep this chart as a summary of this section.

Learning Activity 8

Copy and complete the table to compare the different classes of vertebrates:

  FishAmphibianReptileBirdMammal
 Does it have a backbone?          
 How many limbs (legs)?          
 What body-covering does it have?          
 How does it reproduce          
Cold- or warm-blooded?          
How many chambers in the heart?          
What breathing organs does it have?          
Does it have a tail?          
Any other features that help you to classify it?          

Learning Activity 9

Complete the Exercise 1.1 'Observing and drawing organisms' on p. 1-4 of the Workbook. In this exercise you will practice observing biological specimens, drawing, and calculating magnification. You will need two whole fish to dissect as well as a dissecting blade (can be purchased at a pharmacy).

Learning Activity 10

In your exercise book, answer Questions 1.7 and 1.8 on p.12 of the Coursebook.

Mark your work: the answers to the questions in the coursebook are on p.318 of the coursebook. The answers to the workbook exercise can be found here: Workbook activity.

Common misunderstandings and misconceptions

 Make sure you are able to distinguish between characteristics that apply to all animals and the characteristics that apply to the phylum Vertebrates. Also make sure that you are able to distinguish between the different classes of vertebrates.

 Closing question

What class does the following animal belong to?
It has a moist smooth skin; lives on trees but lays its eggs in water. The young breathe with gills but develops lungs by the time it is an adult.

Closing the lesson

  •  What new things did you learn in this lesson?
  • What did you already know?
  • Is there anything that is confusing you? Ask your parent or teacher to help you.