GRADE SIX SCIENCE
Hello Boys and Girls, We are at the beginning of your third week at school. You should have settled in by now. How have you been working and getting along with your teacher? Have you been doing lots of new things? Have you been completing all your work? Please remember to pay careful attention to your teachers and to the work that you do.
Last week we read the poem, The Spider and the Fly by Merv Howitt. Did you enjoy it? Try to learn it in your spare time. I hope that you found the poem, The Flattered Flying Fish by E.V. Rieu which you should have learnt when you were in Grade Four. Did you read it again?
Last week we also found out a lot about centipedes and millipedes. Have you been seeing any of them around recently? You were also asked to compare the centipede and the millipede. Did you come up with a table like the one below?
Molluscs are invertebrates. They can be found on land and in water. Scientists estimate that there are more than 10,000 species of molluscs alive. They usually have shells made of calcium at the top of their bodies. Below, the body is unsegmented, soft and moist. Mucus, a slimy substance is secreted and this helps the mollusc to move.
Most molluscs have a head with eyes and a pair of tentacles. They breathe by gills and they feed on bacteria and algae off rocks. They are herbivorous.
Let’s now look at crustaceans. Crustacean comes from the Latin word crusta, meaning crust or shell. Crustaceans are a very large group of arthropods. They include lobsters, crabs, shrimp, crayfish, lice and barnacles. Can you name any others? They are mainly aquatic animals. They have exoskeletons which moult in order to grow.
The body of the crustacean is made up of body segments- the head, thorax and abdomen. For some of them the head and thorax are fused. On the head the eyes, jaws and two pairs of antennae can be found. Walking legs and feeding legs can be found on the thorax.
The crab and woodlice usually live on land but lay their eggs in the sea.
Here are pictures of crustaceans.