2. NATURAL SCIENCES GRADE 5 Life & Living Structures

3. http://www.youtube.com/watch?v=8wT5dihdt4E NATURAL SCIENCES GRADE 5

5.  Skeletons are the structures that hold animals (and our) bodies together  Both invertebrate and vertebrate animals have skeletons - these obviously differ  What do you think the main difference between a vertebrate and invertebrate skeleton would be?  Skeletons are mainly designed around how animals move NATURAL SCIENCES GRADE 5

7.  Consist of bones and joints and are inside the body  A backbone protects the spinal cord  The skull protects the brain  Ribs protect the heart and lungs  The bones are hard and form a strong frame structure NATURAL SCIENCES GRADE 5

8.  Have no backbone  Skeleton can be internal or external  They gain structural support for their bodies in other ways NATURAL SCIENCES GRADE 5

9. 1. Hydroskeleton  Found in soft bodied invertebrates and consists of water filled cavities controlled by muscles  E.g. earthworms, starfish and jellyfish NATURAL SCIENCES GRADE 5

10. 2. Endoskeletons  The internal skeleton made from bony and cartilaginous structure  The framework for the animal  The muscles and tissues are formed around the endoskeleton  Especially found in vertebrates NATURAL SCIENCES GRADE 5

11. 3. Exoskeleton  Skeletons found outside the body  Forms a protective coating for the animal  All crustaceans have an exoskeleton  Crabs, spiders, lobsters, insects are all crustaceans  Large exoskeletons are called shells NATURAL SCIENCES GRADE 5