Biology • Topic
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Humans and animals
1.1 Animal skeletons Student’s Book pages 1–3
Scientific enquiry skills
Biology learning objectives
• Obtain and present evidence: Make relevant observations and comparisons in a variety of contexts; present results in drawings, bar charts and tables.
• Know that humans (and some animals) have bony skeletons inside their bodies. • Know that skeletons grow as humans grow, support and protect the body.
Resources • Workbook pages 1 and 2 • Slideshow B1: Does it have a skeleton?
Classroom equipment
Key words • • • • •
bones internal skeleton move support
• large sheets of paper • drawing or colouring equipment • samples of X-rays, if possible • reference books, pictures of different animals with their names
Scientific background Animals can be classified as vertebrates (with backbones) and invertebrates (without backbones). The five groups of vertebrates are: fish, amphibians, reptiles, birds and mammals. (Humans are mammals, but students do not need to know the names of these groups at this stage.) Invertebrates have no internal bone skeleton. They make up more than 98% of the world’s animal species. Many invertebrates have a hydrostatic skeleton (a fluid-filled cavity surrounded by muscles). Others, such as insects and crustaceans, have a hard outer shell. Skeletons are for movement, support and protection of internal organs and soft internal tissue such as nerves. Most vertebrate skeletons are made of bone but some, such as sharks’, are made of cartilage. Weight for weight, bone is one of the strongest materials there is and it is light and flexible.
Introduction � Before turning to the Student’s Book, give each group a large sheet of paper. Ask the students to sketch their ideas of an animal with no skeleton. Once they have done this, explain that most animals have no bony skeleton inside them. Some, such as crabs, have hard outer shells. They need
Students should never touch animal bones that they find lying around in the environment. Bones can carry and spread quite serious diseases, including anthrax.
to shed their shells to grow. Ask: What does the shell do for the animal? (Supports it and protects it.) When the shell is shed, the new shell under it is soft. What could happen to the animal while the shell is still soft? (It could be eaten by a predator.) Jellyfish and worms have a water skeleton, which is a waterfilled space surrounded by muscles. Jellyfish are supported by the water they live in. What happens to a jellyfish out of water? Refer to Student’s Book page 2 and study the photograph with the class. � Ask the class what they already know about bones and skeletons. Explain that they are going to draw a map of these ideas (a concept map). Ask them to write ‘bones and skeletons’ in a circle in the middle of a piece of paper. On the board, show the class how to develop the concept map. Write words for things that are related to bones and skeletons around the outside of the circle. Continue to add to the diagram, drawing lines to link new words to those already there. Let the students copy this class concept map. Some students could write a few words along the lines, to explain how the words are related. Ask each student to show their concept map to a partner and talk about it. � Ask the students to look at page 1 of the Student’s Book. Ask them to say what they are looking at. Discuss whether this skeleton came from a large or
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Biology • Topic
small animal. Ask questions such as: What can you tell about this animal from its skeleton? What body parts can you recognise?
Teaching and learning activities � Ask the students to turn to pages 2 and 3 of the Student’s Book. Emphasise that the frog, fish, snake and bird in the photographs have a bony internal skeleton, made up of lots of bones joined together, and a backbone. The skeleton helps the animal move and supports it, as well as protecting the soft parts inside its body (organs and tissues). � Ask: Which is the best type of skeleton for an animal to have to survive? Why do you think this? Elicit that it depends on the animal’s habitat, the way it needs to move and whether it is the prey of other animals. � Show the class Slideshow B1. As you show each slide, ask them to say whether the animal has a skeleton and what type of skeleton it has. � Let the students work in pairs or individually to complete Workbook page 1. They should think about what they have learned and what they saw in the slideshow.
Graded activities 1 The students can draw on the information in their books for some of the animals, but they may need to do some research of their own to find enough examples. If you have time, you could combine their answers to make a class table.
2 Encourage the students to find examples different
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Humans and animals 1.1
Consolidate and review â—? Show the class images of different animals. Let them sort these into groups according to whether they have a skeleton and what type of skeleton. â—? Let the students complete Workbook page 2 as a consolidation task to remind them that some animals have bony skeletons and that you can normally work out what an animal is by looking at its skeleton. Ask more able students to label the body parts on each skeleton.
Differentiation All of the students should be able to classify the animals they have studied in this lesson. They should be able to find other examples by doing some simple research. Students with a good general knowledge will be able to do the task from memory. Make sure the students do not include animals with exoskeletons in this task. Most of the students should be able to name locusts and beetles as they are mentioned in the text and they should make that association. Some students may have no experience of such animals and they will need to do some research. Make sure the students understand that a shell does not imply an exoskeleton; for instance, tortoises and turtles are vertebrates. Some of the students should be able to answer the questions with little or no help. More able students will delve deeper into the topic to find out how X-rays are produced and used.
from those used in their books and on the slideshow. Use reference books or the internet to find examples. For fun, you could expand this to look at ‘superheroes’ who have exoskeletons, such as Ironman, and discuss how having a bony internal skeleton combined with a hard shell is to their benefit.
3 Some students may be able to answer this question from their own experience, for example if they have ever broken a bone or had a dental X-ray. If you have samples of X-ray photographs, show them to the class. You may like to allow the students to discuss their experiences of having X-rays. Today, most X-rays are produced digitally and the doctor looks at the images on screen; images are seldom printed out.
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