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1.2  Why we need a skeleton


              can move because there are muscles joined to bones of the skeleton.

              Muscles are parts of the body that help us to move.


              Questions



              1  How does the skeleton protect the brain?

              2  Which organs does the rib cage protect?

              3  Why do we need strong bones?
              4  Explain how our skeleton helps us to move.


              Skeletons help us grow



              We grow and get bigger because our skeleton

              grows. An adult’s skeleton is much bigger than a child’s skeleton. An

              adult’s skeleton has stopped growing.



                 Think like a scientist

                 Measuring bone lengths

                 Work with a partner.                            You will need: a tape measure

                 Use the tape measure to measure the length, from end to end, of each

                 other’s:
                 •  upper arm bone              •  upper leg bone             •  lower leg bone.


                 Record the measurements in a table like the one shown here.

                                                    Length in cm
                  Bone
                                               Me               Partner

                  Upper arm bone

                  Lower arm bone
                  Lower leg bone


                 1  Whose bones are longer?
                 2  Predict what you think the length of a

                     teenager’s bones would be. Say why.





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