Natural Sciences and Technology Grade 5 Term 1

Natural Sciences and Technology Grade 5 Term 1: Life and Living Animal Skeletons (PPT 2)

Topic 2 Animal Skeletons of Vertebrates Gr 5 Natural Sciences and Technology – Term 1, Topic 2

What is a Skeleton? • Skeletons are the structures that hold animals (and our) bodies together. • Both invertebrate and vertebrate animals have skeletons, but these skeletons differ from each other. • What do you think the main difference between a vertebrate and invertebrate skeleton would be? • Skeletons are mainly designed around how animals move Gr 5 Natural Sciences and Technology – Term 1, Topic 2

Gr 5 Natural Sciences and Technology – Term 1, Topic 2

s n o t Skele of s e t a r b e t Ver Gr 5 Natural Sciences and Technology – Term 1, Topic 2

Skeletons of Vertebrates • 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. Gr 5 Natural Sciences and Technology – Term 1, Topic 2

s n o t Skele of s e t a r b e t r e v In Gr 5 Natural Sciences and Technology – Term 1, Topic 2

There are 3 different types of skeletons 1. Hydroskeleton 2. Endoskeleton 3. Exoskeleton NATURAL SCIENCES GRADE 5

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

Endoskeleton • 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

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